knuth-errata sources their own package, following CTAN

git-svn-id: svn://tug.org/texlive/trunk@58225 c570f23f-e606-0410-a88d-b1316a301751
author: Karl Berry <karl@freefriends.org> 2021-03-08 18:32:57 +0000
committer: Karl Berry <karl@freefriends.org> 2021-03-08 18:32:57 +0000
commit: b8bbb5c4096ec141403ff5e06e55c25eb7f3c805 (patch)
tree: 64c2b4b1b84765421aba98966cb8a4d9a297015c /Master
parent: a4aa2281f58a777d7188ff716f0b38e78098e480 (diff)
22 files changed, 29295 insertions, 11 deletions
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/cm85.bug b/Master/texmf-dist/doc/generic/knuth-errata/cm85.bug
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+This file is a log of changes made to the "new generation" of Computer Modern
+fonts, after the first output proofs were ready. I had a great deal of
+advice from Neenie Billawala, Matthew Carter, and Richard Southall while
+I was making these revisions.
+
+Entries are in chronological order; thus the most recent news appears
+at the bottom of the file.
+
+-------------------------------------------------------------------------------
+Changes based on the proofsheets of April 26, 1985
+ACCENT.MF:
+ lower the idots, umlauts, and tilde (MC)
+ Polish ell cross: longer stroke in bold
+CMBASE.MF:
+COMLIG.MF:
+ double quotes too close together in bold (MC)
+CSCSPU.MF:
+ SS made from two S's
+GREEKU.MF:
+ Gamma: .25u longer arm
+ Lambda: too narrow (MC,NB)
+ Xi: 1u wider; shorten middle serifs (MC)
+  top and bottom strokes to be arms (NB)
+ Psi: more super; thin the lower curve (MC)
+  add points 3' and 7' for crisp sans
+ Omega: redo the bottom, curl 0 becomes vertical (MC)
+  thin from hair to vair at points 3 and 5
+PUNCT.MF:
+ Monospace period, comma, colon, semicolon made heavier (MC)
+ROMAN.MF:
+ ligs=2 gets ff, fi, etc.; ligs=1 gets only --, '', etc.
+ II kerning introduced
+ kern between a and ' in csc
+ROMAND.MF:
+ 0: med_curve decreased to curve; y2l and y4l raised
+ 1: cap_bar changed to bar in the top stroke
+  sans-serif serifs also use bar as the slab height
+ 2: lighten cap_curve and cap_stem slightly (RS)
+  move point 3 down by .5vair (MC)
+ 4: thin the diagonal still more (NB)
+  bar line moves up one pixel when there's a serif below it
+ 6: move bulb to the right (MC)
+  make the lower left curve more_super (RS,NB)
+ 9: make the upper right curve more_super (RS,NB)
+ROMANL.MF:
+ a: bulb positioned by its center rather than the left (MC)
+ c: right terminals moved closer to the edge (MC,NB)
+  more pull on the inside left (RS)
+ e: less left sidebar in monospace (MC)
+  bold versions to be wider (MC)
+  more pull on inside left (MC,RS)
+ g: lower edge of loop goes one pixel lower
+ varg: point 6 raised above baseline (MC)
+  y0 calculated so that it works when x7l=stem_edge
+  lower arc goes one pixel lower
+ i: monospace version gets more left sidebar (MC)
+  dot moves slightly right (NB)
+  stem'' increased to stem' (MC,RS,NB)
+  slab replaces tiny in correction for dot-too-close
+ j: diminish monospace sidebars (MC)
+  shift slightly to right (MC)
+ k: serif right_jut decreased .8 to .6
+  bug fixed in alpha2 (had y1 not y11)(MC,RS,NB)
+  decreased diagonal weights
+  "if abs(angle(z3-z4)-45)<2:y4:=y3-(x3-x4);fi" rejected; moves y4 down too much
+ n: omit pull inside the arch (MC,RS)
+  introduce stem_shift, shifts this character and others slightly right (MC)
+ o: raise y2l and y4l (RS)
+ s: reduced sidebearing in sans (MC)
+  increased thickness at edges (.35 to .5) (RS)
+  changed to super_arc, and made it more_super (RS)
+  raised the top of upper barb to equal top of the character (RS)
+  removed typo (`tiny' for `fine')
+  reduced flare in upper terminal of sans, and rounded it properly
+ t: width to grow in bold case
+  height made independent of bar_height
+  slightly longer bar (MC)
+ v: decreased left stem (RS)
+ w: decreased stems (MC,RS)
+  monospace version drops middle from 2/3 to .6 and lengthens inner serifs
+ x: decreased left stem
+ y: decreased left stem
+ z: lighter diagonal, longer upper arm (MC,RS,NB)
+ROMANP.MF:
+ $: tau eliminated
+ROMANU.MF:
+ A: decrease right stem (MC)
+  make the bar thinner (MC,NB)
+  bar position based on y0 rather than bar_height
+ C: use cap_band instead of vair' at top and bottom (RS)
+  correct typo: x2l to be reset, not y2l
+ E: middle arm .35u longer, but beak reduced from .7 to .6 (MC)
+ F: top arm .25u longer; middle arm as E (MC)
+ G: same as C; also the bar is raised one pixel
+ J: slightly longer upper left serif
+ K: lower diagonal thinned and moved outward
+ M: monospace version raised still more in middle
+ N: diagonal thinned (MC,RS)
+ O: y2l and y4l raised
+ R: tail should move to the right (MC,RS,NB)
+  bold case gets wider (RS,NB)
+ S: changed as s (RS)
+ V: took stem_corr off the left stem (MC)
+ W: monospace version takes center down from 2/3 to .6, lengthens inner jut
+ X: took stem_corr off the left stem (MC)
+ Y: took stem_corr off the left stem (MC)
+ Z: diagonal made lighter in sans (MC)
+  upper arm made longer (MC,RS)
+ROMLIG.MF:
+ equalize stem weights (RS,NB)
+ROMSPL.MF:
+ ae, oe: incorporate changes of a and e and o
+ ss: more stem weight, less curve weight, less bulb (MC,NB)
+ dotless i,j: see i,j
+ROMSPU.MF:
+ AE: middle arm changes as E (MC)
+  if hefty and monospace, avoid the serif on middle arm
+  bars not aligned if hefty
+  if monospace, middle stem moves to right
+ OE: middle arm changes as in AE (MC)
+  middle stem lightened
+ROMSUB.MF:
+ blankspace: not so close to sides
+SYM.MF:
+CMR10.MF etc:
+ bar_height raised in the quote and bold fonts (MC,NB)
+ comma_depth in cmtt10 increased from 40 to 50 (MC)
+ cap_notch_cut decreased in cmsc10, cmsx10
+ apex_o decreased in cmr10, cmb10, cmbx10, cmbx5, cmcsc10, cmtt10
+ o decreased in cmb10
+ cap_jut decreased from 39 to 34 in cmb10; cap_serif_fit increased 5 to 6
+ cmbx5 gets smaller beak, fudge, cap_ess; more apex_corr
+GENERAL:
+ "robustness" added when points like x8r of "a" are calculated
+  (this affects a,b,d,varg,j,p,q,t,u,dj,ae,6,9,f_stroke)
+ "robustness" also added to avoid curl at end of paths
+  (this affects c,e,s,C,G,S,1,5,ae,oe,breve,parens)
+ "term" subroutine adds robustness for sans-serif terminals
+  (this affects C,G,J,S,f_stroke,j,ss,ae,oe,2,3,5,6,9,$,&,?,@)
+ code revised to use "pos" instead of "penpos" when possible
+Changes based on the proofsheets of May and June, 1985
+ROMAND.MF:
+ 1: use o instead of apex_o
+ 4: bar line height shouldn't depend on bar_height
+ 5: sans-serif lower terminal position raised; depends on upper left edge
+    bug in arm at top (0 for 90) made all hefty arms too small
+ 9: disappears at link
+ROMANU.MF:
+ B: middle bar positioned by its middle, not its bottom (RS)
+    serifed lobes thickened slightly at bottom (RS)
+ C: lower terminal is tilted the other way
+ C,G: upper terminal in sans-serif is tilted slightly
+    upper barb is darkened
+ J: tilt the lower terminal
+ K: lighten the main diagonal (serif case) (RS)
+    lighten the upper diagonal (sans-serif case) (RS)
+ M: remove apex_corr (RS)
+ N: lighten the diagonal
+ P: too light below counter (RS)
+ Q: sharpen upper right corner of sans-serif tail (RS)
+    top of tail thickened and moved slightly left
+ S: less super at upper left and lower right (MC)
+    barb to go below baseline
+    barbs darkened
+    add weight at top, bottom in sans_serif version (RS)
+    tilt the lower terminal like the upper one
+    top weight needs to be maxed with fine.breadth
+ W: top middle stems allowed to overlap in serifed case
+    second inner serif made no longer than left outer serif (MC)
+    ceiling must become floor, to ensure that x5r>=x4r-mid_corr
+ Z: diagonal still too heavy, because previous change was ineffective
+    beaks made darker
+    better positioning of y2 and y3 when tiny is zero
+CSCSPU.MF:
+ J,SS: changes from J and S
+ROMANL.MF:
+ a: inappropriate uses of "fine" are removed
+    bh introduced to guard against "wild" bar heights
+    thin_join introduced at point 9
+    robustness logic changed so that x8l-x8r<=u
+ c: too much weight constrast between strokes in sans_serif (RS)
+    top terminal lowered to match a
+    bottom terminal tilted the other way
+ d: fine.breadth should have been thin_join as in b, p, q
+ e: 1+xpart changed to xpart
+    bottom terminal tilted the other way
+ g: sans-serif ear to use z0l and z0r
+ h,m,n: left inner serifs stay at jut length
+ i,l: mod_width for better fit at lowres
+ j: reposition stem for better fit (use .5w+2.5u, not w-2.5u)
+    remove bug in "pos" change
+ k: upper diagonal serif lengthened from 1.2jut to 1.4jut (RS)
+    diagonals made still lighter
+ r: thin_join introduced
+ s: barb to go below baseline
+    barbs darkened
+    add weight at top, bottom in sans_serif version (RS)
+    tilt the lower terminal like the upper one (RS)
+    top weight needs to be maxed with fine.breadth
+ t: bar extended still more at right (RS)
+ v: decreased the width by .25width_adj#
+ w: overlap allowed as in W
+    second inner serif made no longer than left outer serif (MC)
+    ceiling must become floor, to ensure that x5r>=x4r-mid_corr
+ x: decreased the width by .5width_adj# (RS)
+ y: sans-serif tail curls up too far (RS)
+ z: beaks too light; decrease the diagonal to compensate (RS)
+    better positioning of y2 and y3 when tiny is zero
+ROMSPL.MF:
+ dotless i and j: as i and j
+ ae and oe: bottom terminal tilted the other way
+ ae: corrected as a
+ROMSPU.MF:
+ AE: x12 based on x1l rather than x1, works better in bold cases (RS)
+ OE: left curve not to be pulled
+GREEKU.MF:
+ Phi and Psi: middle parts must keep away from the serifs
+ROMANP.MF:
+ $: strengthened the terminals in sans-serif case, and tilted them
+ &: opened the eye by moving point 8 left .5u (RS)
+ ?: tilted the sans-serif terminal and moved it down a little more
+PUNCT.MF:
+ %: move the diagonal a bit left at the top
+ ( and ): 3.5( changed to 3(.
+ [ and ]: round changed to ceiling and floor, avoids disappearing brackets
+ @: inner a placed by its edges instead of its stem centers (RS)
+ITALL.MF:
+ f: lower bulb moved left; .5 changed to .6 between bulb and stem
+ k: bug in lower right stroke (missing e's)
+ l: bug in italic correction for math fitting (u not u#)
+ m: avoid hooks in monospace version
+ p: lengthed left serif at bottom from .5jut to .75jut
+ x: bulbs moved .25u further out; .5 used between bulb and stem
+ w: avoid hook in monospace version
+ITALIG.MF:
+ all five: changed like f
+ fi: made 1u less wide
+ fl,ffl: made .5u less wide, bulb now touches the l stem
+ ffi: made .75u less wide
+GREEKL.MF:
+ beta, gamma, zeta, xi, omega, varepsilon: +eps at the tight turns
+ gamma: final diagonal should be more slanted (MC)
+ zeta: as tall as xi, shallower diagonal slant (MC)
+ kappa: bug in lower right stroke (missing e's)
+ xi: raise the bottom diagonal and distort arc slightly (MC)
+ chi: introduce slight curve in main diagonal stroke
+ varphi: too wide at right half bowl (MC)
+ITALMS.MF:
+ wp: bulb smaller, bottom a little more open
+ITALD.MF:
+ 5: changed like 5 in ROMAND
+OLDDIG.MF:
+ 2: top a bit narrower, bottom a bit wider (MC)
+ 5: changed like 5 in ROMAND
+SYM.MF:
+ plus-minus: shift depends on u not asc_height
+SYMBOL.MF:
+ minus-plus: shift depends on u not asc_height
+ up-and-down arrows (characters '154 and '155): taller and deeper
+ clubsuit: wider
+ spadesuit: y1+1 changed to y1+.75 (also in clubsuit)
+ROMAN.MF:
+ eliminated kerning between L and O,C,G,Q,U (also in TEXTIT and CSC)
+MATHEX.MF:
+ font_x_height needed to be set, for positioning of accents
+CMB10.MF:
+ dishing is too much (on all bold fonts)
+CMR5.MF:
+ letter_fit decreased 10 to 5
+CMBX5.MF:
+ fudge should be 1 (cap_stem 8=:7 in aps mode was too much)
+ decrease letter_fit drastically; this means f-ligatures must come back
+ lowercase parameters increased by 2/36
+CMBI10.MF:
+ lowercase serifs too short. (same change to all the italic fonts)
+CMSX10.MF:
+ decrease `ess' (RS)
+CMTC10.MF:
+ fudge is too much in lowercase
+CMCC10.MF:
+ lowercase more extended
+ much less letterspace in caps
+ increase lower.cap_curve, decrease lower.o
+CMSQI8.MF:
+ slope shouldn't be so much (RS)
+ increase `ess' (RS)
+
+GENERAL:
+ serif-abutment corrections changed to +1 instead of +2
+ vround used for vertical rounding
+
+CMBASE.MF:
+ new way to set shrink_fit (0,1,2) for monotonicity with letter_fit
+ letter_fit not included in mono_charwd
+ fine must be positive (else we lose barbs)
+ thin_join must be positive (else h_stroke gives a bad pos)
+Changes based on the `version 0' test fonts of July 12
+[not showing hundreds of changes to the `typography' of the programs]
+
+Driver files in general:
+Frequency info (from MANUAL.TEX[tex,dek]) was used to order the ligtables
+font_xheight changed to font_x_height (a change to PLAIN.MF)
+
+Program files in general:
+ use `hround' instead of `round' wherever granularity might be wanted
+ less_rounded was taken out; autorounded occasionally put in
+ arm($,$$,...), the value of y$$ was adjusted by eps (lower) or -eps (upper)
+
+Parameter files in general:
+ new 12pt and 17+pt fonts; more sans serif fonts
+ new comment at bottom of all parameter files: `switch to the driver file'
+
+ACCENT.MF:
+ ^: eps subtracted from y1 (helps avoid degenerate equations in ultralowres)
+ '`: eps added to y1
+
+ROMAN.MF:
+ kern entry for gj had the wrong sign
+ kerns for v removed in sans serif
+ new kern for aj in serif case
+ new kern for ar in sans serif
+
+ROMAND.MF:
+ 3: pos3 needed to be maxed with fine.breadth
+    y1r,y9r needed to be adjusted by eps
+ 6,9: keep x1 on the correct side of x2 at lowlowres
+    (this change also affects OLDDIG, ITALD, and ITALMS partial sign)
+
+ROMANP.MF:
+ $: less_tense bulbs
+
+ROMSPL.MF:
+ ss: ensure x5 not > x4l at low resolutions
+
+ROMLIG.MF:
+ itc shouldn't include the slant...
+
+COMLIG.MF:
+ em dash should be one em wide (add letter_fit# to the adjustments)
+
+BIGOP.MF:
+ \displaystyle coproduct sign had 1.2bracket instead of 1.8bracket
+ charlist syntax changed from commas to colons
+
+BIGDEL.MF:
+ extensible double arrow: position wasn't computed as in top and bottom
+ charlist syntax changed from commas to colons
+
+BIGACC.MF:
+ charlist syntax changed from commas to colons
+
+ITALL.MF:
+ c: point 1 made definitely greater than point 2, for lowlowres
+ q: x4 increased by eps, for lowlowres path intersection
+ r: x4 based on w, not 5u
+ s: max(ess,fine.breadth)
+    add eps and 2eps for lowlowres case (cmmi6 at 100/in)
+
+ITALMS.MF:
+ wp: x6r must not be less than x1r at lowlowres
+
+TSETSL.MF:
+ gamma: last time's bugfix from GREEKL needs to be here too
+
+GREEKL.MF:
+ omega: add 2eps to x4-x6
+ lambda: make sure that y3>y4 at lowlowres
+ zeta: make sure that x2>x0 at lowlowres
+ varsigma: make sure that x1>x2 at lowlowres
+
+CMFIB8.MF:
+ decreased serif_fit, cap_serif_fit; increased curve, cap_curve
+
+CMBASE.MF:
+ l,r made newinternals
+ serif darkness and skew switches now done with boolean variables
+ comma and ammoc: 2eps addedto/subtractedfrom position of x@2
+ mod_width now called change_width
+ ess and cap_ess initialized to preserve ratios with stem and cap_stem
+ mode="string" had to be handled properly
+ ^ and ! changed to t_ and o_, as per new PLAIN conventions
+ make cmchar "outer"
+ t_ is now `relaxed' if it is useless
+ soft is now softjoin in PLAIN (we must set join_radius:=u)
+ eps is now in PLAIN
+ vair is vrounded but at least 1; also slab, etc.
+ cal nibs, yscaled by cap_hair not vair
+ autorounding and smoothing turned off
+
+ROMANL.MF:
+ a: `footed' version is .25u tighter at the right
+ b,d,varg,p,q: x4l position relative to .5(w-serif_fit) not 5u
+ e: testpath uses .r not .l (because of cmss10)
+ f: added 1 at right for monospace lowres versions
+ varg: robust sans-serif terminal at tail
+ m: missing `round' in r adjustment caused noninteger chardx
+ r: x4 based on w, not 5.25u
+ s: watch out that ess isn't so small that badpos error occurs (also ROMANU)
+    barbs made longer; based on middle stroke not just h
+ t: sans-serif terminal made more robust in extreme cases
+ w: in non-monospace hefty serif case, the middle point comes to .8h not h
+ y: robust sans-serif terminal at tail
+
+ROMANU.MF:
+ E: good.y used in y9
+
+PUNCT.MF:
+ []: side_thickness needed to be maxed with crisp.breadth
+     +1 or -1 makes lowres versions more distinctive
+ #: tricky part lost at low resolution
+
+SYMBOL.MF:
+ angle brackets: +1 and -1 to make lowres versions more distinctive
+ aleph: eps added so that y5 will be well defined at lowlowres
+
+SYM.MF:
+ integral sign: bulbs need to be in right direction at lowlowres
+
+CALU.MF:
+ A: apex moved slightly down
+ D: less flat at top, slightly lower lobe
+ F: u less right sidebar
+ H: soft corner at upper left
+ I: middle stroke more like J, upper bar a little further right
+ K: introduce t_ in case of aspect_ratio
+ L: darker
+ M: lighter first diagonal; clean the joins
+ N: lighter diagonal; clean bottom right; .5u less right sidebar
+ O: shortened the inner stroke
+ P: stem comes lower
+ Q: tail not so long at left
+ R: not so flat at top; diagonal less tense; tail less high
+ T: narrower, also changed like I, .5u less right sidebar,
+     heavier, not so high at right
+ U: less extreme curve at lower left
+ V: cleaned up at bottom; lighter first diagonal; slightly wider
+ W: changed like V, but double
+ X: new design, less rigid
+ Y: new design based more on V than U
+ Z: tighter at right, heavier at top and bottom
+
+CMSS10.MF:
+ decreased notch_cut and bar_height
+
+%Note: The following can presumably be deleted; I removed it from CMBASE because
+%  I don't think it is used any more:
+vardef parallel_pos(expr d,u,v,w) = % point at distance $d$ from $u$,
+  % on the line through $w$ that's parallel to |u..v|
+ pair p_; p_=w+whatever*(u-v)=u+whatever*(u-v) rotated 90;
+ numeric d_; d_=length(u-p_);  % distance from $w$ to |u..v|
+ if d_>=d: p_ else: p_+(d+-+d_)*unitvector(v-u) fi enddef;
+Changes subsequent to `Version 1' as released on October 7, 1985.
+
+1. thin_join should be subject to blacker:
+@x in CMBASE.MF, the font_setup routine
+ define_whole_pixels(letter_fit,thin_join,fine,crisp,tiny);
+ define_whole_vertical_pixels(body_height,asc_height,
+  cap_height,fig_height,x_height,comma_depth,desc_depth,serif_drop);
+ define_whole_blacker_pixels(hair,stem,curve,flare,
+@y
+ define_whole_pixels(letter_fit,fine,crisp,tiny);
+ define_whole_vertical_pixels(body_height,asc_height,
+  cap_height,fig_height,x_height,comma_depth,desc_depth,serif_drop);
+ define_whole_blacker_pixels(thin_join,hair,stem,curve,flare,
+@z
+@x
+ if thin_join=0: thin_join:=1; fi
+@y
+@z
+[Note, December 11: My first correction also introduced the statement
+ if fine<thin_join: fine:=thin_join; fi
+in place of
+ if fine=0: fine:=1; fi
+but I can't understand why I would do such a stupid thing!]
+
+2. A new subroutine needed in CMBASE.MF (for cases with aspect_ratio<>1):
+vardef Vround primary y = y_:=vround y;
+ if y_<min_Vround: min_Vround else: y_ fi enddef;
+newinternal y_,min_Vround;
+
+@x related changes to the font_setup routine (in CMBASE.MF):
+ forsuffixes $=vair,bar,slab,cap_bar,cap_band:
+  $:=vround($.#*hppp+blacker); if $<=1: $:=1; fi endfor
+@y
+ define_whole_vertical_blacker_pixels(vair,bar,slab,cap_bar,cap_band);
+@z
+@x
+ vair':=max(1,vround(vair+vair_corr));
+ vstem:=max(1,vround .8[vair,stem]);
+ cap_vstem:=max(1,vround .8[vair,cap_stem]);
+@y
+ vair':=vround(vair+vair_corr);
+ vstem:=vround .8[vair,stem]; cap_vstem:=vround .8[vair,cap_stem];
+@z
+@x
+ pickup pencircle scaled rule_thickness; rule.nib:=savepen;
+@y
+ min_Vround:=max(fine.breadth,crisp.breadth,tiny.breadth);
+ forsuffixes $=vair,bar,slab,cap_bar,cap_band,vair',vstem,cap_vstem:
+  if $<min_Vround: $:=min_Vround; fi endfor
+ pickup pencircle scaled rule_thickness; rule.nib:=savepen;
+@z
+
+The Vround routine is substituted for vround in the programs for
+  Macron, line 6 (in ACCENT.MF)
+  Variant epsilon, line 5 (in GREEKL.MF)
+  Sigma, line 6 (in GREEKU.MF)
+  Omega, line 14 (in GREEKU.MF)
+  2, line 6 (in OLDDIG.MF and ROMAND.MF)
+  7, lines 6 and 8 (in OLDDIG.MF and ROMAND.MF)
+  g, lines 6 and 8 (in ROMANL.MF)
+  s, line 6 (in ROMANL.MF)
+  y, line 9 (in ROMANL.MF)
+  z, line 6 (in ROMANL.MF)
+  &, line 39 (in ROMANP.MF)
+  ?, line 18 (in ROMANP.MF)
+  Spanish open ?, line 17 (in ROMANP.MF)
+  Z, line 6 (in ROMANU.MF)
+  smile and frown, line 4 (in ROMMS.MF)
+
+3. Typo in program for oe ligature.
+@x in file ROMSPL.MF
+else: left_curve=max(tiny.breadth,hround(curve-2stem_corr));
+@y
+else: left_curve=max(fine.breadth,hround(curve-2stem_corr));
+@z
+
+4. Forgotten update to program for SS.
+@x in file CSCSPU.MF
+pickup fine.nib; pos2(max(fine.breadth,s_slab-vround vair_corr),-90);
+pos0(cap_ess,theta); pos7(s_slab,-90);
+x2+x7=2x0=w; x7-x2=if serifs: u else: 0 fi; top y2l=h+o; bot y7r=-o;
+y0=.52h; lft x3l=hround u; rt x6r=hround(w-u);
+x3r-x3l=x6r-x6l=hround .5[s_slab,cap_ess] -fine;
+@y
+numeric ess'; ess'=max(fine.breadth,cap_ess);
+pickup fine.nib; pos2(max(fine.breadth,s_slab-vround vair_corr),-90);
+pos0(ess',theta); pos7(s_slab,-90);
+x2+x7=2x0=w; x7-x2=if serifs: u else: 0 fi; top y2l=h+o; bot y7r=-o;
+y0=.52h; lft x3l=hround u; rt x6r=hround(w-u);
+x3r-x3l=x6r-x6l=hround .5[s_slab,ess']-fine;
+@z
+
+5. Hairline in `k' was overcorrected. (Pavel Curtis)
+@x in file ROMANL.MF
+stem3=max(tiny.breadth,hround(fudged.hair-4stem_corr));
+@y
+stem3=max(tiny.breadth,hround(fudged.hair if hefty:-\\4stem_corr fi));
+@z
+
+6. Too much kerning in "We", etc., in sans-serif fonts
+@x in file ROMAN.MF and TEXSET.MF
+ ligtable "F": "V": "W": "o" kern kk#, "e" kern kk#, "u" kern kk#,
+   "r" kern kk#, "a" kern kk#, "A" kern kkk#,
+@y
+ ligtable "F": "V": "W": if serifs: "o" kern kk#, "e" kern kk#, "u" kern kk#,
+    "r" kern kk#, "a" kern kk#, "A" kern kkk#,
+   else: "o" kern k#, "e" kern k#, "u" kern k#,
+    "r" kern k#, "a" kern k#, "A" kern kk#, fi
+@z
+@x in file TITLE.MF
+ ligtable "F": "V": "W": "A" kern kkk#,
+@y
+ ligtable "F": "V": "W": "A" kern if serifs: kkk# else: kk#\\fi,
+@z
+@x in file CSC.MF
+ ligtable "F": "V": "W": "a" kern kkk#, "A" kern kkk#,
+@y
+ ligtable "F": "V": "W": if serifs: "a" kern kkk#, "A" kern kkk#,
+  else: "a" kern kk#, "A" kern kk#, fi
+@z
+@x in file CSC.MF
+ ligtable "f": "v": "w": "a" kern kkk#,
+@y
+ ligtable "f": "v": "w": "a" kern if serifs: kkk# else: kk#\\fi,
+@z
+
+7. dish serifs need to be more robust when dishing is very small.
+@x in file CMBASE.MF
+  if y$<y$$: dish_out=bot y$; dish_in=dish_out+dish;
+  else: dish_out=top y$; dish_in=dish_out-dish; fi
+  erase fill\\(x@1,dish_out)..(x$,dish_in){right}..(x@@1,dish_out)--cycle;
+@y
+  if y$<y$$: dish_out=bot y$; dish_in=dish_out+dish; let rev_=reverse;
+  else: dish_out=top y$; dish_in=dish_out-dish; let rev_=relax; fi
+  erase fill rev_
+   ((x@1,dish_out)..(x$,dish_in){right}..(x@@1,dish_out)--cycle);
+@z
+
+8. more robustness in case thin_join is too big
+@x in file ROMANL.MF, program for "b"
+pos4(vair,90); pos5(curve,0);
+pos6(vair,-90); penpos7(x3l-x3r,-180);
+rt x3l=1/3[rt x2,edge]; y3=1/8[bar_height,x_height];
+@y
+pos4(vair,90); pos5(curve,0); pos6(vair,-90); penpos7(x3l-x3r,-180);
+rt x3l=max(rt x3l-(lft x3r-tiny.lft x2l),1/3[rt x2,edge]);
+y3=1/8[bar_height,x_height];
+@z
+@x ibid, program for "d"
+pos4(vair,90); pos5(curve,180);
+pos6(vair,270); penpos7(x3r-x3l,360);
+lft x3l=1/3[lft x2,edge]; y3=1/8[bar_height,x_height];
+@y
+pos4(vair,90); pos5(curve,180); pos6(vair,270); penpos7(x3r-x3l,360);
+lft x3l=min(lft x3l-(rt x3r-tiny.rt x2r),1/3[lft x2,edge]);
+y3=1/8[bar_height,x_height];
+@z
+@x ibid, program for variant "g"
+pos4(vair,90); pos5(curve,180);
+pos6(vair,270); penpos7(x3r-x3l,360);
+lft x3l=2/3[lft x2,edge]; y3=bar_height;
+@y
+pos4(vair,90); pos5(curve,180); pos6(vair,270); penpos7(x3r-x3l,360);
+lft x3l=min(lft x3l-(rt x3r-tiny.rt x2r),2/3[lft x2,edge]); y3=bar_height;
+@z
+@x ibid, program for "p"
+rt x3l=1/3[rt x2,edge]; y3=1/8[bar_height,x_height];
+@y
+rt x3l=max(rt x3l-(lft x3r-tiny.lft x2l), 1/3[rt x2,edge]);
+y3=1/8[bar_height,x_height];
+@z
+@x ibid, program for "q"
+lft x3l=2/3[lft x2,edge]; y3=bar_height;
+@y
+lft x3l=min(lft x3l-(rt x3r-tiny.rt x2r),2/3[lft x2,edge]); y3=bar_height;
+@z
+@x ibid, proram for "q"
+x6l=x4l-.2u; bot y6r=-oo;
+lft x7l=1/3[lft x2,edge]; y7=min(y3,y6+y4-y3+.6vair);
+@y
+x6l=x4l-.2u; bot y6r=-oo; y7=min(y3,y6+y4-y3+.6vair);
+lft x7l=min(lft x7l-(rt x7r-tiny.rt x2r),1/3[lft x2,edge]);
+@z
+
+9. More robust "c" and "e" and "C"
+@x in file ROMANL.MF, program for "c"
+ (x,y4l)=whatever[z4r,z5l]; x4l:=x;
+@y
+ (x,y4l)=whatever[z4r,z5l]; x4l:=min(x,x4l+.5u);
+@z
+@x ibid, program for "e"
+ (x,y4l)=whatever[z4r,z5]; x4l:=x;
+@y
+ (x,y4l)=whatever[z4r,z5]; x4l:=min(x,x4l+.5u);
+@z
+@x in file ROMSPL.MF, programs for "ae" and "oe"
+ (x,y14l)=whatever[z14r,z15]; x14l:=x;
+@y
+ (x,y14l)=whatever[z14r,z15]; x14l:=min(x,x14l+.5u);
+@z
+@x in file ROMANU.MF, programs for "C" and "G"
+ (x2l',y2l)=whatever[z2r,z1l]; x2l:=x2l';
+ (x4l',y4l)=whatever[z4r,z5l]; x4l:=x4l';
+@y
+ (x2l',y2l)=whatever[z2r,z1l]; x2l:=min(x2l',x2l+.5u);
+ (x4l',y4l)=whatever[z4r,z5l]; x4l:=min(x4l',x4l+.5u);
+@z
+
+10. More robust foot in "a"
+@x in file ROMANL.MF
+  filldraw stroke z5'e---z10e...z11e{right};  % foot
+@y
+  pos12(shaved_stem,0); x11=x12; top y12=slab+eps;
+  filldraw z5'l---z10l...z11l{right}--z11r
+   --z12r{left}...z10r+.75(z12-z11)---z5'r--cycle;  % foot
+@z
+
+11. Barbs less sharp
+@x in file ROMANU.MF, programs for "C" and "G"
+ x6=x1r; top y6=h+o; x1r-x1'=2cap_curve-fine; y1'=y1;
+ path upper_arc; upper_arc=z1{x2-x1,10(y2-y1)}..z2{left};
+ numeric t; t=xpart(upper_arc intersectiontimes (z6--z1'));
+ filldraw z1r--z6--subpath(t,0) of upper_arc--cycle; % barb
+@y [actually "G" had something similar but not identical]
+ pos6(.3[fine.breadth,cap_hair],0); x6r=x1r; top y6=h+o;
+ x1r-x1'=2cap_curve-fine; y1'=y1;
+ path upper_arc; upper_arc=z1{x2-x1,10(y2-y1)}..z2{left};
+ numeric t; t=xpart(upper_arc intersectiontimes (z6l--z1'));
+ filldraw z1r--z6r--z6l--subpath(t,0) of upper_arc--cycle; % barb
+@z
+@x ibid, program for "S"
+ x10=x1l; top y10=top y2l; x9=x8r; bot y9=bot y7r;
+ x1l-x1'=x8'-x8r=1.6cap_curve-fine; y1'=y1; y8'=y8;
+ numeric t; t=xpart(upper_arc intersectiontimes(z10--z1'));
+ filldraw z1l--z10--subpath(t,0) of upper_arc--cycle;  % upper barb
+ t:=xpart(lower_arc intersectiontimes(z9--z8'));
+ filldraw z8r--z9--subpath(t,1) of lower_arc--cycle;  % lower barb
+@y
+ pos10(.3[fine.breadth,cap_hair],0); pos9(.3[fine.breadth,cap_hair],0);
+ x10r=x1l; top y10=top y2l; x9l=x8r; bot y9=bot y7r;
+ x1l-x1'=x8'-x8r=1.6cap_curve-fine; y1'=y1; y8'=y8;
+ numeric t; t=xpart(upper_arc intersectiontimes(z10l--z1'));
+ filldraw z1l--z10r--z10l--subpath(t,0) of upper_arc--cycle;  % upper barb
+ t:=xpart(lower_arc intersectiontimes(z9r--z8'));
+ filldraw z8r--z9l--z9r--subpath(t,1) of lower_arc--cycle;  % lower barb
+@z [the same change goes into file CSCSPU.MF, the program for two S's]
+@x in file ROMANL.MF, program for "s"
+ x10=x1l; top y10=top y2l; x9=x8r; bot y9=bot y7r;
+ x1l-x1'=x8'-x8r=1.6curve-fine; y1'=y1; y8'=y8;
+ numeric t; t=xpart(upper_arc intersectiontimes(z10--z1'));
+ filldraw z1l--z10--subpath(t,0) of upper_arc--cycle;  % upper barb
+ t:=xpart(lower_arc intersectiontimes(z9--z8'));
+ filldraw z8r--z9--subpath(t,1) of lower_arc--cycle;  % lower barb
+@y
+ pos10(.3[fine.breadth,cap_hair],0); pos9(.3[fine.breadth,cap_hair],0);
+ x10r=x1l; top y10=top y2l; x9l=x8r; bot y9=bot y7r;
+ x1l-x1'=x8'-x8r=1.6cap_curve-fine; y1'=y1; y8'=y8;
+ numeric t; t=xpart(upper_arc intersectiontimes(z10l--z1'));
+ filldraw z1l--z10r--z10l--subpath(t,0) of upper_arc--cycle;  % upper barb
+ t:=xpart(lower_arc intersectiontimes(z9r--z8'));
+ filldraw z8r--z9l--z9r--subpath(t,1) of lower_arc--cycle;  % lower barb
+@z
+
+12. Italic ampersand more robust
+@x in file ITALP
+ & pulled_arc.e(9,10)...{dir(theta+90)}z11e;  % bowls, loop, and stem
+@y
+ & {{interim superness:=more_super; pulled_arc.e(9,10)}}
+ ..tension .9 and 1..{dir(theta+100)}z11e;  % bowls, loop, and stem
+@z
+
+13. h_stroke more robust (esp in case of typewriter-style m)
+@x in file CMBASE
+ pickup fine.nib; pos@0(thin_join,180);
+@y
+ penpos@0(min(rt x$r-lft x$l,thin_join)-fine,180); pickup fine.nib;
+@z
+
+14. eliminate dishing in conflict with arm.
+Put a new subroutine into CMBASE.MF:
+def nodish_serif(suffix $,$$,@)(expr left_darkness,left_jut)
+  (suffix @@)(expr right_darkness,right_jut) suffix modifier =
+ serif($,$$,@,left_darkness,-left_jut) modifier;
+ serif($,$$,@@,right_darkness,right_jut) modifier; enddef;
+
+Now use this instead of dish_serif in the following places:
+GREEKU:  Gamma, upper serif
+  Pi, both upper serifs (fix erroneous comments!)
+SYMBOL:  Amalgamation, both lower serifs (fix erroneous comments!)
+ROMANU:  B, both serifs
+  D, both serifs
+  E, both serifs
+  F, upper serif
+  L, lower serif
+  P, upper serif
+  R, upper serif
+  T, upper bracketing
+ROMSPU: AE, upper and lower middle serifs
+
+15. Change #2 wasn't quite good enough!
+@x in CMBASE
+ min_Vround:=max(fine.breadth,crisp.breadth,tiny.breadth);
+@y
+ min_Vround:=max(fine.breadth,crisp.breadth,tiny.breadth);
+ if min_Vround<vround min_Vround: min_Vround:=vround min_Vround; fi
+ if flare<vround flare: flare:=vround flare; fi
+@z
+
+16. body_depth# is now called paren_depth#, since body_depth is
+computed differently. (This is a cosmetic change only; it affects
+files CMBASE, PUNCT, SYM, SYMBOL, and ROMMS.)
+
+17. more robust Sigma
+@x in GREEKU, page 9
+top y1=h; bot y2=h-slab; bot y4=0; x3l-x1l=4/11(w-2u); y3=.5h;
+@y
+top y1=h; bot y2=h-slab-eps; bot y4=0; x3l-x1l=4/11(w-2u); y3=.5h;
+@z
+@x in BIGOP, page 7
+top_arm_thickness=rule_thickness;
+@y
+top_arm_thickness=Vround rule_thickness;
+@z
+@x in BIGOP, page 7 (this change needed twice)
+top y1=0; bot y2=-top_arm_thickness; bot y4=-d; y3=-.5d;
+@y
+top y1=0; bot y2=-top_arm_thickness-eps; bot y4=-d; y3=-.5d;
+@z
+
+18. yet another refinement of change #2
+@x in CMBASE
+ forsuffixes $=vair,bar,slab,cap_bar,cap_band,vair',vstem,cap_vstem:
+@y
+ forsuffixes $=vair,bar,slab,cap_bar,cap_band,vair',vstem,cap_vstem,bold:
+@z
+
+19. slightly more robust `k'
+@x in ROMANL
+top y3=x_height; rt x3r=hround(r-letter_fit-.7u-right_jut);
+bot y6=0; rt x6r=hround(r-letter_fit-.3u-right_jut);
+@y
+top y3=x_height; rt x3r=hround(r-letter_fit-.7u-right_jut)+eps;
+bot y6=0; rt x6r=hround(r-letter_fit-.3u-right_jut)+eps;
+@z
+
+20. small parameter changes for consistency
+@x in CMBX6
+dish#:=.9/36pt#;    % amount erased at top or bottom of serifs
+@y
+dish#:=.8/36pt#;    % amount erased at top or bottom of serifs
+@z
+@x in CMBX5
+dish#:=.75/36pt#;    % amount erased at top or bottom of serifs
+@y
+dish#:=.7/36pt#;    % amount erased at top or bottom of serifs
+@z
+@x in CMSS9 and CMSSI9 [these two lines are not consecutive in the files!]
+notch_cut#:=23/36pt#;    % maximum breadth above or below notches
+cap_notch_cut#:=29/36pt#;  % max breadth above/below uppercase notches
+@y
+notch_cut#:=17/36pt#;    % maximum breadth above or below notches
+cap_notch_cut#:=24/36pt#;  % max breadth above/below uppercase notches
+@z
+@x in CMSS8 and CMSSI8 [these two lines are not consecutive in the files!]
+notch_cut#:=21/36pt#;    % maximum breadth above or below notches
+cap_notch_cut#:=27/36pt#;  % max breadth above/below uppercase notches
+@y
+notch_cut#:=16/36pt#;    % maximum breadth above or below notches
+cap_notch_cut#:=22/36pt#;  % max breadth above/below uppercase notches
+@z
+@x in CMTI9
+cap_hair#:=10/36pt#;    % uppercase hairline breadth
+@y
+cap_hair#:=11/36pt#;    % uppercase hairline breadth
+@z
+@x in CMTI8
+cap_hair#:=9.5/36pt#;    % uppercase hairline breadth
+@y
+cap_hair#:=11/36pt#;    % uppercase hairline breadth
+@z
+@x in CMTI7
+cap_hair#:=9/36pt#;    % uppercase hairline breadth
+@y
+cap_hair#:=10.5/36pt#;    % uppercase hairline breadth
+@z
+@x in CMTCSC10
+lower.cap_notch_cut#:=24pt#;  % max breadth above/below uppercase notches
+@y
+lower.cap_notch_cut#:=24/36pt#;  % max breadth above/below uppercase notches
+@z
+
+21. New parameter file CMFI10 was added; font_identifier is "CMFI".
+Also changed the name `cmit10' to `cmitt10'; font_identifier is "CMITT".
+
+22. Still more changes for robustness (based on resolution h120 x v108).
+@x in ROMAND and ITALD, "5"
+bot y5=vround(.53h-vair); top y6r=vround .61803h+o;
+@y
+bot y5=vround(.53h-vair); top y6r=max(vround .61803h+o,top y6r+y5+eps-y6l);
+@z
+@x in OLDDIG, "5"
+bot y5=vround(.53[-d,h]-vair); top y6r=(vround .61803[-d,h])+o;
+@y
+bot y5=vround(.53[-d,h]-vair);
+top y6r=max((vround .61803[-d,h])+o,top y6r+y5+eps-y6l);
+@z
+@x in ROMANU, "C"
+ bot y1=vround max(.6h,x_height-.5vair); y5=good.y .95(h-y1);
+@y
+ bot y1=min(vround max(.6h,x_height-.5vair),bot y2l-eps);
+ y5=max(good.y .95(h-y1),y4l+eps);
+@z
+@x in ROMANU, "G"
+ bot y1=vround max(.6h,x_height-.5vair);
+@y
+ bot y1=min(vround max(.6h,x_height-.5vair),bot y2l-eps);
+@z
+@x in GREEKL page 6 and TSETSL page 8
+y1=.9h; top y2l=h+oo; top y8r=x_height+oo; y4=y8;
+@y
+top y2l=h+oo; y1=min(.9h,y2r-eps); top y8r=x_height+oo; y4=y8;
+@z
+@x in GREEKL page 16
+x6=x7=w-2u; x8=.5w+.5u; y6=-.3d; y8=-3/4d-oo; bot y7r=-d-oo;
+@y
+x6=x7=w-2u; x8=.5w+.5u; y6=-.3d; bot y7r=-d-oo; y8=max(-3/4d-oo,y7l);
+@z
+@x in ITALL page 12, ITALMS page 6, ITALSP page 4
+lft x5r=hround-.5u; x4=1/3(w-u);
+@y
+x4=1/3(w-u); lft x5r=min(hround-.5u,lft x5r+x4-x5l-eps);
+@z
+@x in ROMANL, "g"
+x11=x13=.5w; bot y13r=-d-oo-1; x14=w-x12; z10'l=z10l;
+@y
+x11=x13=max(.5w,x10+eps); bot y13r=-d-oo-1; x14=w-x12; z10'l=z10l;
+@z
+@x in ROMANL, "s"
+ filldraw stroke z1e..tension.9..{left}z2e;  % upper arc and terminal
+ filldraw stroke z7e{left}..z8e; fi  % lower arc and terminal
+@y
+ filldraw stroke term.e(2,1,right,.9,4);  % upper arc and terminal
+ filldraw stroke term.e(7,8,left,1,4); fi  % lower arc and terminal
+@z
+@x in ROMANL, "c"
+ filldraw stroke pulled_super_arc.e(2,3)(.7superpull)
+  & pulled_super_arc.e(3,4)(.5superpull)
+  ..tension .9 and 1..z5e; fi  % arc and lower terminal
+@y
+ forsuffixes e=l,r: path p.e; p.e=z4e{right}..tension .9 and 1..z5e;
+  if angle direction 1 of p.e>75:
+   p.e:=z4e{right}..tension atleast.9 and 1..{dir 75}z5e; fi endfor
+ filldraw stroke pulled_super_arc.e(2,3)(.7superpull)
+  & pulled_super_arc.e(3,4)(.5superpull) & p.e; fi  % arc and lower terminal
+@z
+@x in ROMSPL, page 5
+lft x8r=hround(stem_edge+.5u+1); x7=max(x8l+eps,.4[lft x8r,x6]);
+@y
+lft x8r=min(hround(stem_edge+.5u+1),lft x8r+x6r-2eps-x8l);
+x7=max(x8l+eps,.4[lft x8r,x6]);
+@z
+@x in ROMAND and OLDDIG, "2"
+ lft x1r=hround .75u; bot y1l=vround .7h; y1r:=good.y y1r; x1l:=good.x x1l;
+@y
+ lft x1r=hround .75u; bot y1l=vround .7h; y1r:=good.y y1r+eps; x1l:=good.x x1l;
+@z
+@x in SYMBOL, page 42 (Fraktur R)
+z=(z20{up}...{right}z21)intersectionpoint(z22l--z22l+(h,0) rotated theta);
+@y
+path p; p=z20{up}...(z21--(w,y21));
+z=p intersectionpoint(z22l--z22l+(h,0) rotated theta);
+@z
+
+23. Another consequence of change 2:
+"vround" should be "Vround" in the BIGDEL programs for extensible arrows
+(five times).
+Also five times in the BIGOP programs for summation, product, coproduct.
+
+24. Cosmetic change to bring CMBASE in line with PLAIN.
+@x in CMBASE.MF
+def pickup secondary q =
+ if numeric q: currentpen:=pen_[q];
+  pen_top:=pen_top_[q];  pen_bot:=pen_bot_[q];
+  pen_lft:=pen_lft_[q];  pen_rt:=pen_rt_[q];
+  currentpen_path:=pen_path_[q];
+  if known breadth_[q]: currentbreadth:=breadth_[q]; fi
+ else: currentpen:=q yscaled aspect_ratio;
+  pen_top:=(ypart penoffset left of currentpen)_o_;
+  pen_bot:=(ypart penoffset right of currentpen)_o_;
+  pen_lft:=xpart penoffset down of currentpen;
+  pen_rt:=xpart penoffset up of currentpen;
+  path currentpen_path;
+ fi enddef;
+@y
+def numeric_pickup_ primary q =
+ currentpen:=pen_[q];
+ pen_lft:=pen_lft_[q];  pen_rt:=pen_rt_[q];
+ pen_top:=pen_top_[q];  pen_bot:=pen_bot_[q];
+ currentpen_path:=pen_path_[q];
+ if known breadth_[q]: currentbreadth:=breadth_[q]; fi enddef;
+@z
+
+25. false italic correction in lambda of texset fonts (Feb 25, 1986)
+@x in TEXSET
+mode_setup; font_setup;
+@y
+mode_setup; font_setup; mono_charic#:=0;
+@z
+@x ibid
+slant:=mono_charic#:=0;  % the remaining characters will not be slanted
+@y
+slant:=0;  % the remaining characters will not be slanted
+@z
+[now remove the occurrences of `charic:=0;' in TSETSL, as they are unnecessary]
+
+*** The above changes are incorporated into the published book,
+*** Computer Modern Typefaces; this is "Version 2" (released March 5, 1986).
+Changes subsequent to `Version 2' as published in C&T, Volume E:
+
+@x in GREEKU
+numeric shaved_stem; shaved_stem=hround .9[vair,.85cap_stem];
+@y
+numeric shaved_stem; shaved_stem=hround .9[vair,.85cap_stem];
+if shaved_stem<crisp.breadth: shaved_stem:=crisp.breadth; fi
+@z
+
+@x in CMSS9 [this affects the TFM file to a small extent!]
+fig_height#:=236/36pt#;    % height of numerals
+@y
+fig_height#:=212/36pt#;    % height of numerals
+@z
+
+@x in CMSSI9 [this affects the TFM file in ten hts and eleven italcorrs]
+fig_height#:=236/36pt#;    % height of numerals
+@y
+fig_height#:=212/36pt#;    % height of numerals
+@z
+
+@x in CMR17 [no change to TFM file]
+curve#:=41/36pt#;    % lowercase curve breadth
+@y
+curve#:=40/36pt#;    % lowercase curve breadth
+@z
+@x
+cap_stem#:=40/36pt#;    % uppercase stem breadth
+cap_curve#:=48/36pt#;    % uppercase curve breadth
+@y
+cap_stem#:=41/36pt#;    % uppercase stem breadth
+cap_curve#:=47/36pt#;    % uppercase curve breadth
+@z
+@x
+serif_drop#:=17/36pt#;    % vertical drop of sloped serifs
+@y
+serif_drop#:=7/36pt#;    % vertical drop of sloped serifs
+@z
+
+@x in ROMAND [this fixes the `disappearing hairline' in some lowres 8's]
+ lower_side=hround(.5[hair,stem]+stem_corr);
+@y
+ lower_side=hround(.5[hair,stem]+stem_corr);
+ if lower_side>1.2upper_side: upper_side:=lower_side; fi
+@z
+% Note: the SAME change should also be made in files ITALD and OLDDIG
+
+@x in ITALL [this fixes italic ell especially at low resolutions]
+top y1=h; x1=x2; filldraw stroke z1e--z2e;  % stem
+@y
+top y1=h; x1=x2; filldraw stroke z1e--z2'e;  % stem
+@z
+
+@x in SYM, the plus-or-minus character
+x1=x2=.5w; lft x3=lft=x5=hround u-eps; x4=x6=w-x3;
+@y
+x1=x2=.5w; lft x3=lft x5=hround u-eps; x4=x6=w-x3;
+@z actually the code worked but it was "infelicitous"
+
+@x in SYMBOL, the minus-or-plus character
+x1=x2=.5w; lft x3=lft=x5=hround u-eps; x4=x6=w-x3;
+@y
+x1=x2=.5w; lft x3=lft x5=hround u-eps; x4=x6=w-x3;
+@z actually the code worked but it was "infelicitous"
+
+@x in ROMANU, letter J [fixes a bug if dish=0 and crisp<tiny and serifs]
+ bulb(3,4,5);  % bulb
+@y
+ pickup tiny.nib; bulb(3,4,5);  % bulb
+@z
+
+@x in ROMANL, letter w [makes notch_cut more useful]
+ else: fill diag_end(6r,5r,1,1,5l,6l)--.5[z5l,z6l]
+   --.5[z5r,z6r]--cycle;% middle stem
+@y
+ else: fill diag_end(6r,5r,1,1,5l,6l)--.9[z5l,z6l]
+   ..{z5-z6}.1[z5r,z6r]--cycle; % middle stem
+@z the same change applies also to letter W in ROMANU
+
+@x in CMBASE, makes lowres types (especially TT) look better
+ define_blacker_pixels(notch_cut,cap_notch_cut);
+@y
+ define_blacker_pixels(notch_cut,cap_notch_cut);
+ forsuffixes $=notch_cut,cap_notch_cut: if $<3: $:=3; fi endfor
+@z
+
+@x in BIGOP, the \displaystyle coproduct sign
+lft x11=hround u; x1l-x11=x2l-x12=x22-x2r=hround cap_jut;
+@y
+lft x11=hround u; x1l-x11=x2l-x12=x22-x2r=hround 1.6cap_jut;
+@z
+
+@x in ROMANL, the letter m
+lft x1l=hround(2.5u-.5stem); x1l=x1'l=x2l=x2'l;
+lft x3l=hround(.5w-.5stem); x5-x3=x3-x1;
+if not monospace: r:=hround(x5+x1)-l; fi  % change width for better fit
+@y
+lft x1l=hround(2.5u-.5stem); x1l=x1'l=x2l=x2'l; % stem, sic
+lft x3l=hround(.5w-.5mfudged.stem); x5-x3=x3-x1;
+if not monospace: r:=hround(x5+x1)+r-w; fi  % change width for better fit
+@z
+
+@x a new routine for CMBASE, following change_width
+@y
+def center_on(expr x) = if not monospace: % change width for symmetric fit
+ r:=r+2x-w; w:=2x; fi enddef;
+@z
+@x in SYMBOL, the elementary division operator
+x3-.5dot_size=hround(.5w-.5dot_size); w:=r:=2x3;
+@y
+x3-.5dot_size=hround(.5w-.5dot_size); center_on(x3);
+@z
+Similarly, whenever the construction "w:=r:=2x*" appears, change it to
+"center_on(x*)". This happens in the programs for elementary division operator
+(as noted above), large triangle, large inverted triangle, lattice top,
+lattice bottom, dagger mark, double dagger mark, club/diamond/heart/spade suit
+(all in SYMBOL), plus the diamond operator and universal quantifier in SYM.
+The following additional change needs to be made in the programs
+for lattice top and lattice bottom:
+@x
+x1=x2=good.x .5w; center_on(x1); lft x3=hround u; x4=r-x3;
+@y
+x1=x2=good.x .5w; center_on(x1); lft x3=hround u; x4=w-x3;
+@z
+
+@x in SYMBOL, at end of zero-width slash
+labels(1,2); zero_width; endchar;
+@y
+labels(5,6); zero_width; endchar;
+@z
+
+@x in ROMANU, the letter Q (this change simply labels point 8 on proofs)
+math_fit(-.3cap_height#*slant-.5u#,ic#); penlabels(1,2,3,4,5,6,7); endchar;
+@y
+math_fit(-.3cap_height#*slant-.5u#,ic#);
+penlabels(1,2,3,4,5,6,7,8); endchar;
+@z
+
+@x in ROMANL, the letter i (this change by Jonathan Kew makes the dot rounder)
+if serifs: x3r=max(x1r,x1+.5(dot_diam-tiny)-.2jut) else: x3=x1-.5 fi;
+@y
+if serifs: x3r=max(x1r,hround(x1+.5dot_diam-.2jut)-.5tiny)
+else: x3=x1-.5 fi;
+@z
+
+-----------Improvements made in January 1992
+[No change to TFM files]
+@x in cmbase (improve lowres as suggested by John Hobby)
+def normal_adjust_fit(expr left_adjustment,right_adjustment) =
+ l:=-hround(left_adjustment*hppp)-letter_fit;
+ interim xoffset:=-l;
+ charwd:=charwd+2letter_fit#+left_adjustment+right_adjustment;
+ r:=l+hround(charwd*hppp)-shrink_fit;
+ w:=r-hround(right_adjustment*hppp)-letter_fit;
+ enddef;
+
+def mono_adjust_fit(expr left_adjustment,right_adjustment) =
+ numeric expansion_factor;
+ mono_charwd#=2letter_fit#
+   +expansion_factor*(charwd+left_adjustment+right_adjustment);
+ forsuffixes $=u,jut,cap_jut,beak_jut,apex_corr:
+   $:=$.#*expansion_factor*hppp; endfor
+ l:=-hround(left_adjustment*expansion_factor*hppp)-letter_fit;
+ interim xoffset:=-l;
+ r:=l+mono_charwd-shrink_fit;
+ w:=r-hround(right_adjustment*expansion_factor*hppp)-letter_fit;
+ charwd:=mono_charwd#; charic:=mono_charic#;
+ enddef;
+@y
+def do_expansion(expr expansion_factor) =
+ forsuffixes $=u,jut,cap_jut,beak_jut,apex_corr:
+   $:=$.#*expansion_factor*hppp; endfor
+enddef;
+
+def normal_adjust_fit(expr left_adjustment,right_adjustment) =
+ numeric charwd_in; charwd_in=charwd;
+ l:=-hround(left_adjustment*hppp)-letter_fit;
+ interim xoffset:=-l;
+ charwd:=charwd+2letter_fit#+left_adjustment+right_adjustment;
+ r:=l+hround(charwd*hppp)-shrink_fit;
+ w:=r-hround(right_adjustment*hppp)-letter_fit;
+ do_expansion(w/(charwd_in*hppp));
+ enddef;
+
+def mono_adjust_fit(expr left_adjustment,right_adjustment) =
+ numeric charwd_in; charwd_in=charwd;
+ numeric expansion_factor;
+ mono_charwd#=2letter_fit#
+   +expansion_factor*(charwd+left_adjustment+right_adjustment);
+ l:=-hround(left_adjustment*expansion_factor*hppp)-letter_fit;
+ interim xoffset:=-l;
+ r:=l+mono_charwd-shrink_fit;
+ w:=r-hround(right_adjustment*expansion_factor*hppp)-letter_fit;
+ charwd:=mono_charwd#; charic:=mono_charic#;
+ do_expansion(w/(charwd_in*hppp));
+ enddef;
+@z
+@x in SYM, Downward arrow
+pos3(bar,90); pos4(bar,90);
+lft x1l=hround(.5w-.5rule_thickness); y1+.5rule_thickness=h;
+x0=x1=x2; bot y0=-d; x0-x3=x4-x0=3u+eps;
+y3=y4=y0+.24asc_height+eps;
+pos5(bar,angle(z4-z0)); z5l=z0;
+pos6(bar,angle(z3-z0)); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y (make arrowheads heavier, as suggested by Zapf)
+pos3(rule_thickness,90); pos4(rule_thickness,90);
+lft x1l=hround(.5w-.5rule_thickness); y1+.5rule_thickness=h;
+x0=x1=x2; bot y0=-d; x0-x3=x4-x0=if monospace:3u else:4u fi+eps;
+y3=y4=y0+if monospace:.24 else:.36 fi asc_height+eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYM, Upward arrow
+pos3(bar,90); pos4(bar,90);
+lft x1l=hround(.5w-.5rule_thickness); y1-.5rule_thickness=-d;
+x0=x1=x2; top y0=h; x0-x3=x4-x0=3u+eps;
+y3=y4=y0-.24asc_height-eps;
+pos5(bar,angle(z4-z0)); z5l=z0;
+pos6(bar,angle(z3-z0)); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos3(rule_thickness,90); pos4(rule_thickness,90);
+lft x1l=hround(.5w-.5rule_thickness); y1-.5rule_thickness=-d;
+x0=x1=x2; top y0=h; x0-x3=x4-x0=if monospace:3u else:4u fi+eps;
+y3=y4=y0-if monospace:.24 else:.36 fi asc_height-eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYM, Leftward arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis; x1+.5rule_thickness=hround(w-u); lft x0=hround u;
+y3-y0=y0-y4=.24asc_height+eps; x3=x4=x0+3u+eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis; x1+.5rule_thickness=hround(w-u); lft x0=hround u;
+y3-y0=y0-y4=if monospace:.24 else:.36 fi asc_height+eps;
+x3=x4=x0+if monospace:3u else:4u fi+eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYM, Rightward arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis; x1-.5rule_thickness=hround u; rt x0=hround(w-u);
+y3-y0=y0-y4=.24asc_height+eps; x3=x4=x0-4u-eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis; x1-.5rule_thickness=hround u; rt x0=hround(w-u);
+y3-y0=y0-y4=if monospace:.24 else:.36 fi asc_height+eps;
+x3=x4=x0-if monospace:3u else:4u fi-eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYM, Left-and-right arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis if monospace:+vround.3asc_height fi; lft x0=hround u;
+if monospace: x1+.5rule_thickness=hround(w-u) else: x1=.5w fi;
+y3-y0=y0-y4=.24asc_height+eps; x3=x4=x0+3u+eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis if monospace:+vround.3asc_height fi; lft x0=hround u;
+if monospace: x1+.5rule_thickness=hround(w-u) else: x1=.5w fi;
+y3-y0=y0-y4=if monospace:.24 else:.36 fi asc_height+eps;
+x3=x4=x0+if monospace:3u else:4u fi+eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x ibid
+pos11(rule_thickness,90); pos12(rule_thickness,90); pos13(bar,0); pos14(bar,0);
+y10=y11=y12=math_axis if monospace:-vround.3asc_height fi;
+rt x10=hround(w-u);
+if monospace: x11-.5rule_thickness=hround u else: x11=.5w fi;
+y13-y10=y10-y14=.24asc_height+eps; x13=x14=x10-3u-eps;
+pos15(bar,angle(z14-z10)); z15l=z10; pos16(bar,angle(z13-z10)); z16l=z10;
+z19=.381966[.5[z13,z14],z10];
+@y
+pos11(rule_thickness,90); pos12(rule_thickness,90);
+pos13(rule_thickness,0); pos14(rule_thickness,0);
+y10=y11=y12=math_axis if monospace:-vround.3asc_height fi;
+rt x10=hround(w-u);
+if monospace: x11-.5rule_thickness=hround u else: x11=.5w fi;
+y13-y10=y10-y14=if monospace:.24 else:.36 fi asc_height+eps;
+x13=x14=x10-if monospace:3u else:4u fi-eps;
+pos15(rule_thickness,angle(z14-z10)); z15l=z10;
+pos16(rule_thickness,angle(z13-z10)); z16l=z10;
+z19=.2[.5[z13,z14],z10];
+@z
+@x in SYMBOL, Up-and-down arrow
+pos3(bar,90); pos4(bar,90);
+lft x1l=hround(.5w-.5rule_thickness); y1=.5[-d,h];
+x0=x1=x2; bot y0=-d-o; x0-x3=x4-x0=3u+eps;
+y3=y4=y0+.24asc_height+eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos3(rule_thickness,90); pos4(rule_thickness,90);
+lft x1l=hround(.5w-.5rule_thickness); y1=.5[-d,h];
+x0=x1=x2; bot y0=-d-o; x0-x3=x4-x0=4u+eps;
+y3=y4=y0+.36asc_height+eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x ibid
+pos13(bar,90); pos14(bar,90);
+x10=x11=x12; top y10=h+o; x10-x13=x14-x10=3u+eps;
+y13=y14=y10-.36asc_height-eps;
+pos15(bar,angle(z14-z10)); z15l=z10;
+pos16(bar,angle(z13-z10)); z16l=z10;
+z19=.381966[.5[z13,z14],z10];
+@y
+pos13(rule_thickness,90); pos14(rule_thickness,90);
+x10=x11=x12; top y10=h+o; x10-x13=x14-x10=4u+eps;
+y13=y14=y10-.24asc_height-eps;
+pos15(rule_thickness,angle(z14-z10)); z15l=z10;
+pos16(rule_thickness,angle(z13-z10)); z16l=z10;
+z19=.2[.5[z13,z14],z10];
+@z
+@x in SYMBOL, Northeast arrow
+pos3(bar,theta); pos4(bar,theta);
+y3=y0; x4=x0; x0-x3=y0-y4=delta+eps;
+pos5(bar,-90); z5l=z0; pos6(bar,-180); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos3(rule_thickness,theta); pos4(rule_thickness,theta);
+z3-z0=(-4u,.36asc_height) rotated theta;
+z4-z0=(-4u,-.36asc_height) rotated theta;
+pos5(rule_thickness,-90); z5l=z0; pos6(rule_thickness,-180); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYMBOL, Southeast arrow
+pos3(bar,theta); pos4(bar,theta);
+x3=x0; y4=y0; y3-y0=x0-x4=delta+eps;
+pos5(bar,180); z5l=z0; pos6(bar,90); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos3(rule_thickness,theta); pos4(rule_thickness,theta);
+z3-z0=(-4u,.36asc_height) rotated theta;
+z4-z0=(-4u,-.36asc_height) rotated theta;
+pos5(rule_thickness,180); z5l=z0; pos6(rule_thickness,90); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYMBOL, Northwest arrow
+pos3(bar,-180+theta); pos4(bar,-180+theta);
+x3=x0; y4=y0; x4-x0=y0-y3=delta+eps;
+pos5(bar,0); z5l=z0; pos6(bar,-90); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos3(rule_thickness,-180+theta); pos4(rule_thickness,-180+theta);
+z4-z0=(4u,.36asc_height) rotated theta;
+z3-z0=(4u,-.36asc_height) rotated theta;
+pos5(rule_thickness,0); z5l=z0; pos6(rule_thickness,-90); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in SYMBOL, Southwest arrow
+pos3(bar,-180+theta); pos4(bar,-180+theta);
+y3=y0; x4=x0; x3-x0=y4-y0=delta+eps;
+pos5(bar,90); z5l=z0; pos6(bar,0); z6l=z0;
+z9=.381966[.5[z3,z4],z0];
+@y
+pos3(rule_thickness,-180+theta); pos4(rule_thickness,-180+theta);
+z4-z0=(4u,.36asc_height) rotated theta;
+z3-z0=(4u,-.36asc_height) rotated theta;
+pos5(rule_thickness,90); z5l=z0; pos6(rule_thickness,0); z6l=z0;
+z9=.2[.5[z3,z4],z0];
+@z
+@x in ROMMS, Leftward top half arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis; x1+.5rule_thickness=hround(w-u); lft x0=hround u;
+y3-y0=y0-y4=.24asc_height+eps; x3=x4=x0+3u+eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis; x1+.5rule_thickness=hround(w-u); lft x0=hround u;
+y3-y0=y0-y4=.36asc_height+eps; x3=x4=x0+4u+eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+@z
+@x in ROMMS, Leftward bottom half arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis; x1+.5rule_thickness=hround(w-u); lft x0=hround u;
+y3-y0=y0-y4=.24asc_height+eps; x3=x4=x0+3u+eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis; x1+.5rule_thickness=hround(w-u); lft x0=hround u;
+y3-y0=y0-y4=.36asc_height+eps; x3=x4=x0+4u+eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+@z
+@x in ROMMS, Rightward top half arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis; x1-.5rule_thickness=hround u; rt x0=hround(w-u);
+y3-y0=y0-y4=.24asc_height+eps; x3=x4=x0-3u-eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis; x1-.5rule_thickness=hround u; rt x0=hround(w-u);
+y3-y0=y0-y4=.36asc_height+eps; x3=x4=x0-4u-eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+@z
+@x in ROMMS, Rightward bottom half arrow
+pos1(rule_thickness,90); pos2(rule_thickness,90); pos3(bar,0); pos4(bar,0);
+y0=y1=y2=math_axis; x1-.5rule_thickness=hround u; rt x0=hround(w-u);
+y3-y0=y0-y4=.asc_height+eps; x3=x4=x0-3u-eps;
+pos5(bar,angle(z4-z0)); z5l=z0; pos6(bar,angle(z3-z0)); z6l=z0;
+@y
+pos1(rule_thickness,90); pos2(rule_thickness,90);
+pos3(rule_thickness,0); pos4(rule_thickness,0);
+y0=y1=y2=math_axis; x1-.5rule_thickness=hround u; rt x0=hround(w-u);
+y3-y0=y0-y4=.36asc_height+eps; x3=x4=x0-4u-eps;
+pos5(rule_thickness,angle(z4-z0)); z5l=z0;
+pos6(rule_thickness,angle(z3-z0)); z6l=z0;
+@z
+@x in CALU, Calligraphic F
+top y1=top y6=h; z2=.5[z3,z1]+bend;
+bot y3=-o; y4=.1h; y5=y2; y7=.9h;
+draw flex(z1,z2,z3) softjoin (z3...{x4-x3,5(y4-y3)}z4);  % stem
+draw z1-flourish_change{up}...z1---z6...{down}z7;  %  upper bar
+@y
+top y1=top y6=h; z2=.5[z3,z1]+1.2bend;
+bot y3=-o; y4=.1h; y5=y2; y7=.9h;
+draw flex(z1,z2,z3) softjoin (z3...{x4-x3,5(y4-y3)}z4);  % stem
+draw z1-flourish_change{up}...(z1-(u,0))---z6...{down}z7;  %  upper bar
+@z
+@x in CALU, Calligraphic H
+lft x1=lft x3=0; rt x4=rt x6=.8w; rt x9=w;
+top y1=top y4=h; bot y3=-o; bot y6=bot_flourish_line; y9=y6+.1h;
+z2=.6[z3,z1]+bend; z5=.4[z6,z4]-2bend;
+path p[]; p1=flex(z1,z2,z3); p2=flex(z4,z5,z6);
+p3=(-w,.55h)--(2w,.55h);
+lft z7=p3 intersectionpoint p1; rt z8=p3 intersectionpoint p2;
+draw (z1-flourish_change{up}....z1-(u,0)---z1) softjoin p1;  % left stem
+@y
+lft x1=lft x3=.5u; rt x4=rt x6=.8w-.6u; rt x9=w;
+top y1=top y4=h; bot y3=-.06h; bot y6=bot_flourish_line; y9=y6+.1h;
+z2=.6[z3,z1]+bend; z5=.4[z6,z4]-bend;
+path p[]; p1=flex(z1,z2,z3); p2=flex(z4,z5,z6);
+p3=(-w,.45h)--(2w,.45h);
+rt z7+2bend=p3 intersectionpoint p1; rt z8=p3 intersectionpoint p2;
+draw (z1-flourish_change-bend{curl2}....z1-(u,0)---z1) softjoin p1;  % left stem
+@z
+@x in CALU, Calligraphic I
+lft x0=0; x1=.9w; x2=x4=.5w; x5=.2w; x6=.75w; rt x7=w;
+@y
+lft x0=0; x1=.9w; x2=x4=.5w; x5=.2w; x6=.8w; rt x7=1.05w;
+@z
+@x in CALU, Calligraphic T
+x1=x3=.5w; lft x4=0; x5=w-x6=.25w; rt x7=w;
+x1=.47w; x3=.5w; lft x4=0; x5=w-x6=.25w; rt x7=1.05w;
+z2=.5[z3,z1]+bend;
+x1-x8=x9-x1=2u; y8=y9=y3;
+z0=1/3[z1,z6];
+draw z0{left}...z2{down}...{left}z8;  % stem
+draw z8--z9;  % foot
+draw z4{up}...z5{right}...z6{right}...{up}z7;  % arms
+math_fit(.5u#-5/7h#*slant,-u#); labels(1,2,3,4,5,6,7,8,9); endchar;
+@y
+x1=.47w; x3=.5w; lft x4=0; x5=.25w; x6=.85w; rt x7=1.05w;
+top y1=h; bot y3=-.1h; y4=3/4h; top y5=top y6=h; top y7=1.05h;
+z2=.3[z3,z1]+bend;
+top y0=y1; x0=x2;
+z8=(2u,.2h);
+draw z0---z2...z3;  % stem
+draw z4{curl 2}...z5{right}...z6{right}...{up}z7;  % arms
+math_fit(.5u#-5/7h#*slant,-u#); labels(1,2,3,4,5,6,7); endchar;
+@z
+@x in GREEKL, lowercase delta
+pos1(hair,-180); pos2(vair,-90);
+numeric theta; theta=angle(18u,-h);
+pos3(stem,theta+90); pos4(stem,theta+90); pos5(1/4[hair,stem],20);
+pos6(vair,-90); pos7(curve,-180); pos8(vair,-270);
+rt x1l=hround(w-2u+.5hair); x2=.5w; x3r=3u; rt x5r=hround(w-u);
+x4=x6=x8=.5w+.5u; lft x7r=hround(1.5u-.5curve);
+top y2l=h+oo; y1=min(.9h,y2r-eps); top y8r=x_height+oo; y4=y8;
+z4-z3=whatever*(18u,-h); y5=y7=.5[y6,y8]; bot y6=-oo;
+filldraw stroke z1e{x2-x1,3(y2-y1)}...z2e{left}...z3e---z4e
+ ....z5e{down}...pulled_arc.e(6,7) & pulled_arc.e(7,8);  % hook and bowl
+math_fit(-.3x_height#*slant+.5curve#-u#,.7x_height#*slant-.5u#);
+penlabels(1,2,3,4,5,6,7,8); endchar;
+@y
+x0=-u; y0=1.1h;
+numeric light_flare; light_flare=2/3[vair,flare];
+x1=w-2u-.5light_flare; y1=h-.5light_flare;
+numeric theta; theta=angle (z1-z0);
+pos1(light_flare,theta-90); pos2(.2[vair,light_flare],-90); pos3(vair,theta);
+x2=x3+u; y2=h;
+x4=x6=.5w+.5u; top y8r=x_height+oo; z4=z8;
+pos6(vair,-90); pos7(stem,-180); pos8(vair,-270);
+pos4(stem,angle(z4-z0)+90); pos5(stem,30);
+z3=.5[.5[z1,z4],z0];
+y5+.1x_height=y7=.5[y6,y8]; bot y6=-oo;
+lft x7r=hround(1.4u-.5stem); rt x5r=hround(w-u);
+filldraw stroke z1e{z0-z1e}....z2e....z3e{(z0-z1)rotated 90}
+ ...z4e{z4e-.8[z4,z0]}
+ ....z5e{down}...pulled_arc.e(6,7) & pulled_arc.e(7,8);  % hook and bowl
+filldraw z1r{z1r-z0}...z1l{z0-z1l}--cycle; % bulb
+math_fit(-.3x_height#*slant+.5curve#-u#,.7x_height#*slant-.5u#);
+penlabels(0,1,2,3,4,5,6,7,8); endchar;
+@z
+@x in TSETSL, lowercase delta for extended ASCII
+pos1(hair,-180); pos2(vair,-90);
+numeric theta; theta=angle(18u,-h);
+pos3(stem,theta+90); pos4(stem,theta+90); pos5(1/4[hair,stem],20);
+pos6(vair,-90); pos7(curve,-180); pos8(vair,-270);
+rt x1l=hround(w-2u+.5hair); x2=.5w; x3r=3u; rt x5r=hround(w-u);
+x4=x6=x8=.5w+.5u; lft x7r=hround(1.5u-.5curve);
+top y2l=h+oo; y1=min(.9h,y2r-eps); top y8r=x_height+oo; y4=y8;
+z4-z3=whatever*(18u,-h); y5=y7=.5[y6,y8]; bot y6=-oo;
+filldraw stroke z1e{x2-x1,3(y2-y1)}...z2e{left}...z3e---z4e
+ ....z5e{down}...pulled_arc.e(6,7) & pulled_arc.e(7,8);  % hook and bowl
+penlabels(1,2,3,4,5,6,7,8); endchar;
+@y this next line differs from GREEKL, but the other lines agree
+x0=-u; y0=1.05h;
+numeric light_flare; light_flare=2/3[vair,flare];
+x1=w-2u-.5light_flare; y1=h-.5light_flare;
+numeric theta; theta=angle (z1-z0);
+pos1(light_flare,theta-90); pos2(.2[vair,light_flare],-90); pos3(vair,theta);
+x2=x3+u; y2=h;
+x4=x6=.5w+.5u; top y8r=x_height+oo; z4=z8;
+pos6(vair,-90); pos7(stem,-180); pos8(vair,-270);
+pos4(stem,angle(z4-z0)+90); pos5(stem,30);
+z3=.5[.5[z1,z4],z0];
+y5+.1x_height=y7=.5[y6,y8]; bot y6=-oo;
+lft x7r=hround(1.4u-.5stem); rt x5r=hround(w-u);
+filldraw stroke z1e{z0-z1e}....z2e....z3e{(z0-z1)rotated 90}
+ ...z4e{z4e-.8[z4,z0]}
+ ....z5e{down}...pulled_arc.e(6,7) & pulled_arc.e(7,8);  % hook and bowl
+filldraw z1r{z1r-z0}...z1l{z0-z1l}--cycle; % bulb
+penlabels(0,1,2,3,4,5,6,7,8); endchar;
+@z
+
+----------- Changes made after the fourth printing (1993) of Volume E
+
+@x in CSCSPU, letter J [fixes a bug if dish=0 and crisp<tiny and serifs]
+ bulb(3,4,5);  % bulb
+@y
+ pickup tiny.nib; bulb(3,4,5);  % bulb
+@z
+
+@x in BIGDEL, two harmless bugs caught by Robert Hunt
+"Extensible vertical arrow--extension module";
+@y
+cmchar "Extensible vertical arrow--extension module";
+@z
+@x
+"Extensible double vertical arrow--extension module";
+@y
+cmchar "Extensible double vertical arrow--extension module";
+@z
+
+@x in GREEKU, letter Phi (hi-res glitch found by Robert Hunt)
+lft x1l=lft x2l=hround(.5w-.5cap_stem); top y1=h; bot y2=0;
+@y
+lft x1l=lft x2l=hround(.5w-.5shaved_stem); top y1=h; bot y2=0;
+@z
+@x in GREEKU, letter Psi similarly
+lft x1l=lft x2l=hround(.5w-.5cap_stem); top y1=h; bot y2=0;
+@y
+lft x1l=lft x2l=hround(.5w-.5shaved_stem); top y1=h; bot y2=0;
+@z
+
+@x in BIGOP, teststyle integral sign
+x5=.5[x4,x6]; x4-x6=1.2u; lft x5r=hround(.5w-.5stem);
+@y
+x5=.5[x4,x6]; x4-x6=1.2u; lft x5r=hround(.5w-.5curve);
+@z
+@x same, displaystyle integral sign
+x5=.5[x4,x6]; x4-x6=4.8u; lft x5r=hround(.5w-.5stem);
+@y
+x5=.5[x4,x6]; x4-x6=4.8u; lft x5r=hround(.5w-.5max_size);
+@z
+@x same, textstyle contour integral sign
+x5=.5[x4,x6]; x4-x6=1.2u; lft x5r=hround(.5w-.5stem);
+@y
+x5=.5[x4,x6]; x4-x6=1.2u; lft x5r=hround(.5w-.5curve);
+@z
+@x same, displaystyle contour integral sign
+x5=.5[x4,x6]; x4-x6=4.8u; lft x5r=hround(.5w-.5stem);
+@y
+x5=.5[x4,x6]; x4-x6=4.8u; lft x5r=hround(.5w-.5max_size);
+@z
+
+@x in ITALMS, the partial differential sign
+path p; p=pulled_super_arc.l(3,4)(pull);
+@y
+path p; {{interim superness:=more_super; p=pulled_super_arc.l(3,4)(pull)}};
+@z
+
+@x in SYMBOL, the elementary division operator
+beginarithchar(oct"004"); pickup rule.nib;
+x3-.5dot_size=hround(.5w-.5dot_size); center_on(x3);
+y3+.5dot_size=vround(math_axis+math_spread[.5x_height,.6x_height]+.5dot_size);
+@y note that pickup rule.nib leaves currentbreadth unchanged
+beginarithchar(oct"004"); pickup fine.nib; pickup rule.nib;
+numeric del; del=dot_size-currentbreadth; % currentbreadth=fine
+x3-.5del=good.x(.5w-.5del); center_on(x3);
+y3+.5del=good.y(math_axis+math_spread[.5x_height,.6x_height]+.5del);
+@z
+
+@x in CMBASE, compute_spread can force even spreads for better rounding
+ spread:=ceiling(spread#*hppp)+eps; enddef;
+@y
+ spread:=2ceiling(spread#*hppp/2)+eps; enddef;
+@z
+
+@x in CMBASE, better diag_ratio routine avoids overflow in hi-res chars
+ numeric a_,b_; b_=b/y; a_=a*a-b_*b_;
+ (a*(c++y*sqrt a_)-b_*c)/a_/y enddef;
+@y
+ numeric a_,b_,c_; b_=b/y; c_=c/y; a_=a*a-b_*b_;
+ (a*(c_++sqrt a_)-b_*c_)/a_ enddef;
+@z
+
+@x in ROMAND, numeral 3, allow hi-res cminch to run without overflow (MacKay)
+x4=1/3[x5,x3l]; z4=z5+whatever*(150u,h);
+@y
+x4=1/3[x5,x3l]; z4=z5+whatever*(15u,.1h);
+@z
+
+@x in ITALP, the Sterling sign (bug caught by Yannis Haralambous)
+lft x6r=hround u; x7=3u; x8=w-3.5u; rt x9r=hround(w-u);
+@y
+lft x6r=hround u; x7=3u; x8=w-3.5u; rt x9l=hround(w-u);
+@z
+
+@x in GREEKL, lowercase omega, I made minor changes for new edition of TAOCP:
+y1+.5hair=h; x1=x2+.75u; pos1(hair,angle(2(x1-x2),y1-y2)+90);
+@y
+y1+.5hair=h; x1=x2+.75u; pos1(hair+dw,angle(2(x1-x2),y1-y2)+90);
+@z
+@x
+x3=.5[x2,x4]; x7+.25u=.5[x6,x8]; rt x8r=hround(w-.5u);
+@y
+x3=.5[x2,x4]; x7-.25u=.5[x6,x8]; rt x8r=hround(w-.5u);
+@z
+
+@x in GREEKL, lowercase beta, I made minor changes for new edition of TAOCP:
+pos3(stem,0); pos4(vair,-90); pos5(hair,-180);
+pos6(vair,-270); pos7(curve,-360); pos8(vair,-450); pos9(hair,-540);
+x0=x1=x9; lft x0l=hround(1.5u-.5hair); x2=x4=x6=x8=.5w+.25u;
+rt x3r=hround(w-1.5u); rt x7r=hround(w-1.5u+.5curve); rt x5l=hround(x4-u);
+bot y0=-d; y1=top y6r=x_height; top y2r=h+oo; y3=.5[y2,y4];
+y5=.5[y4,y6]; top y6r-bot y4r=vstem+eps; bot y8=-oo; y7=y9=.5[y6,y8];
+@y (this change also is made in TSETSL)
+pos3(.8[hair,stem],0); pos4(vair,-90); pos5(hair,-180);
+pos6(vair,-270); pos7(stem,-360); pos8(vair,-450); pos9(hair,-540);
+x0=x1=x9; lft x0l=hround(1.5u-.5hair); x2=x4=x6=x8=.5w-.25u;
+rt x3r=hround(w-1.75u); rt x7r=hround(w-u); rt x5l=hround(x4-u);
+bot y0=-d; y1=top y6r=x_height; top y2r=h+oo; y3=.5[y2,y4];
+y5=.5[y4,y6]; top y6r-bot y4r=vstem+eps; bot y8=-oo; y7=y9=.55[y6,y8];
+@z
+
+@x in ROMANU, less overshoot on uppercase sans serif C (for Vol 2 of TAOCP)
+ top y1r=vround .95h+o; top y2r=h+o; y3=.5h;
+ bot y4r=-o; bot y5r=vround .08h-o; y5l:=good.y y5l; x5l:=good.x x5l;
+@y
+ top y1r=vround .95h+oo; top y2r=h+oo; y3=.5h;
+ bot y4r=-oo; bot y5r=vround .08h-oo; y5l:=good.y y5l; x5l:=good.x x5l;
+@z
+
+@x in ROMANU, likewise for G
+ top y1r=vround .93h+o; top y2r=h+o; y3=.5h;
+ bot y4r=-o; bot y5r=vround .07h-o;
+@y
+ top y1r=vround .93h+oo; top y2r=h+oo; y3=.5h;
+ bot y4r=-oo; bot y5r=vround .07h-oo;
+@z
+
+@x in SYMBOL, spade suit, a cosmetic change that doesn't affect any fonts:
+labels(1,2,3,5,6,10,11,12,13,14,15); endchar;
+@y
+labels(1,2,3,5,6,7,8,9,10,11,12,13,14,15); endchar;
+@z
+
+@x in CMBASE, sloped_serif.l never used $$ except rarely in letter p
+ y@0=max(y@2l-bracket,y$$)-eps;
+@y and in letter p, it was wrong to do so! (but not in any normal font)
+ y@0=y@2l-bracket-eps;
+@z
+@x sloped_serif.r never used $$ in any reasonable way at all
+ y@0=min(y@2l+bracket,y$$)+eps;
+@y
+ y@0=y@2l+bracket+eps;
+@z
+
+in ITALD, programs for 6 and 9: same change as above for partial derivative
+in OLDDIG, programs for 6 and 9: same change as above for partial derivative
+in ROMAND, programs for 6 and 9: same change as above for partial derivative
+in TSETSL, program for partial derivative: same change as above
+
+@x in ROMANL, slight change to cmss10 and cmssbx10 `g' improves meta-ness
+loop_top=Vround .77[vair,fudged.stem];
+@y
+loop_top=if serifs: Vround .77[vair,fudged.stem] else: vair fi;
+@z
+
+@x in CMBASE, recent change shouldn't clobber a_, b_, and c_ of plain.mf
+ numeric a_,b_,c_; b_=b/y; c_=c/y; a_=a*a-b_*b_;
+ (a*(c_++sqrt a_)-b_*c_)/a_ enddef;
+@y
+ numeric aa_,bb_,cc_; bb_=b/y; cc_=c/y; aa_=a*a-bb_*bb_;
+ (a*(cc_++sqrt aa_)-bb_*cc_)/aa_ enddef;
+@z
+
+@x in ITALMS, Arrow (vector) accent
+lft x1=hround .5u; x2=w-x1; y1=y2=good.x .7[x_height,asc_height];
+@y a correction of almost purely academic interest
+lft x1=hround .5u; x2=w-x1; y1=y2=good.y .7[x_height,asc_height];
+@z
+
+the following patches make the arrows more robust, but essentially unchanged
+@x in SYM, Downward arrow
+ --z2r---z1r..z1l---z2l--subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@y
+ ---z1r..z1l---subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@z
+@x in SYM, Upward arrow
+ --z2r---z1r..z1l---z2l--subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ ---z1r..z1l---subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in SYM, Leftward arrow
+ --z2l---z1l..z1r---z2r--subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@z
+@x in SYM, Rightward arrow
+ --z2l---z1l..z1r---z2r--subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in SYM, Left-and-right arrow
+ --z2l---z1l..z1r---z2r--subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@z
+@x ibid
+ --z12l---z11l..z11r---z12r--subpath (t,0) of\\(z13l{z19-z13}..z15r)
+@y
+ ---z11l..z11r---subpath (t,0) of\\(z13l{z19-z13}..z15r)
+@z
+@x in SYMBOL, Up-and-down arrow
+ --z2r---z1r..z1l---z2l--subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@y
+ ---z1r..z1l---subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@z
+@x ibid
+ --z12r---z11r..z11l---z12l--subpath (t,0) of\\(z13l{z19-z13}..z15r)
+@y
+ ---z11r..z11l---subpath (t,0) of\\(z13l{z19-z13}..z15r)
+@z
+@x in SYMBOL, Northeast arrow
+ --z2l---z1l..z1r---z2r--subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in SYMBOL, Southeast arrow
+ --z2l---z1l..z1r---z2r
+ --subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in SYMBOL, Northwest arrow
+ --z2l---z1l..z1r---z2r--subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in SYMBOL, Southwest arrow
+ --z2l---z1l..z1r---z2r
+ --subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ ---z1l..z1r---subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in ROMMS, Leftward top half arrow
+filldraw z0--(x0,y2l)---z1l..z1r---z2r
+ ..subpath (t,0) of\\(z3r..{2(x0-x3),y0-y3}z5r)
+@y
+filldraw z0--(x0,y2l)--z1l{right}..{left}z1r
+ --subpath (t,0) of\\(z3r..{2(x0-x3),y0-y3}z5r)
+@z
+@x in ROMMS, Leftward bottom half arrow
+filldraw z0{2(x4-x0),y4-y0}..z4l
+ --subpath (0,t) of\\(z4r..{2(x0-x4),y0-y4}z6r)
+@y
+ --z1l{right}..{left}z1r--(x0,y2r)--cycle;  % arrowhead and stem
+@z
+@x in ROMMS, Rightward top half arrow
+filldraw z0--(x0,y2l)---z1l..z1r---z2r
+ ..subpath (t,0) of\\(z3l..{2(x0-x3),y0-y3}z5r)
+@y
+filldraw z0--(x0,y2l)--z1l{left}..{right}z1r
+ --subpath (t,0) of\\(z3l..{2(x0-x3),y0-y3}z5r)
+@z
+@x in ROMMS, Rightward bottom half arrow
+ ..z2l---z1l..z1r---(x0,y2r)--cycle;  % arrowhead and stem
+@y
+ --z1l{left}..{right}z1r--(x0,y2r)--cycle;  % arrowhead and stem
+@z
+@x in BIGDEL, Extensible vertical arrow--top
+ --z2r---z1r--z1l---z2l--subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@y
+ --z1r--z1l--subpath (t,0) of\\(z3l{z9-z3}..z5r)
+@z
+@x in BIGDEL, Extensible vertical arrow--bottom
+ --z2r---z1r--z1l---z2l--subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@y
+ --z1r--z1l--subpath (t,0) of\\(z3r{z9-z3}..z5r)
+@z
+
+@x in ROMLIG, the ligature fi
+ x13=x11-.5; top y14r=min(2x_height,h+1); top y11=x_height;
+@y make the center of the dot consistent with ordinary i, in sans-serif fonts
+ x13=x11-.5; top y14r=min(10/7x_height+.5bulb_diam,h)+1; top y11=x_height;
+@z
+@x in ROMLIG, the ligature ffi
+ x23=x21-.5; top y24r=min(2x_height,h+1); top y21=x_height;
+@y same corrections as to fi
+ x23=x21-.5; top y24r=min(10/7x_height+.5bulb_diam,h)+1; top y21=x_height;
+@z
+
+@x in SYMBOL, the circle operator
+lft x6=hround u; x2=w-x6; top y8=h; y2=math_axis;
+@y this correction makes it a circle even at small size, low resolution
+lft x6=hround u; x2=w-x6; top y8=h; y8-y4=x2-x6;
+@z
+@x in SYMBOL, the bullet
+lft x6=hround u; x2=w-x6; top y8=h; y2=math_axis; circle_points;
+@y likewise
+lft x6=hround u; x2=w-x6; top y8=h; y8-y4=x2-x6; circle_points;
+@z
+
+@x in ROMAND, the numeral 2
+ ..z3e{down}.. z4e---z5e--z6e;  % stroke
+@y it's more robust to avoid --- next to -- (in case of tiny loops)
+ ..z3e{down}..{z5e-z4e}z4e--z5e--z6e;  % stroke
+@z
+@x in OLDDIG, oldstyle numeral 2
+ ..z3e{down}.. z4e---z5e--z6e;  % stroke
+@y likewise
+ ..z3e{down}..{z5e-z4e}z4e--z5e--z6e;  % stroke
+@z
+
+@x in CSC, after the second font_setup
+extra_endchar:=extra_endchar&"charcode:=charcode+code_offset";
+@y
+extra_endchar:=extra_endchar&"charcode:=charcode+code_offset;";
+@z
+
+@x in ACCENT, in program for Breve
+numeric mid_thickness; mid_thickness=vround 1/3[vair,stem];
+@y
+numeric mid_thickness; mid_thickness=Vround 1/3[vair,stem];
+@z
+
+@x in CMBASE, a more robust arm routine fixes the 7 in cmbx5,6,7,8
+  filldraw z$$l{z@1-z$$l}...darkness[z@1,.5[z@2,z$$l] ]...z@2
+   ---z$l--z$r--z@0--z$$r--cycle; % arm and beak
+@y
+  path p_; p_= z$$l{z@1-z$$l}...darkness[z@1,.5[z@2,z$$l] ]...z@2
+    ---z$l--z$r--z@0--z$$r--cycle;
+  if (y$$>y$) <> (ypart precontrol 1 of p_ > ypart postcontrol 1 of p_):
+    p_:=z$$l{z@1-z$$l}...darkness[z@1,.5[z@2,z$$l] ]
+     ---z$l--z$r--z@0--z$$r--cycle; fi
+  filldraw p_; % arm and beak
+@z
+
+@x in CALU, I decided in July 2005 that I really wanted a less swashy F
+top y1=top y6=h; z2=.5[z3,z1]+1.2bend;
+bot y3=-o; y4=.1h; y5=y2; y7=.9h;
+draw flex(z1,z2,z3) softjoin (z3...{x4-x3,5(y4-y3)}z4);  % stem
+draw z1-flourish_change{up}...(z1-(u,0))---z6...{down}z7;  %  upper bar
+@y
+top y1=top y6=h; z2=.5[z3,z1]+bend;
+bot y3=-o; y4=.1h; y5=y2; y7=.9h;
+draw flex(z1,z2,z3) softjoin (z3...{x4-x3,5(y4-y3)}z4);  % stem
+draw z1-flourish_change+(0,.15asc_height){up}...{right}(z1-(2u,0))
+        ---z6...{down}z7;  %  upper bar
+@z
+
+@x in SYMBOL, two points of Hardy's asymptotic equivalence sign were unlabeled
+labels(1,2,3,4); endchar;
+@y
+labels(1,2,3,4,5,6); endchar;
+@z
+
+@x in GREEKL, correct a tiny notch that can show up at hires (Charles Duan)
+filldraw z1l--z2l--z--z1r--cycle;  % stem
+@y
+filldraw z1l--z2l...(x3,y2l)...z--z1r--cycle;  % stem
+@z
+
+@x in GREEKL, make almost-invisible semantic corrections to beta
+x0=x1=x9; lft x0l=hround(1.5u-.5hair); x2=x4=x6=x8=.5w-.25u;
+@y
+x0=x1=x9; lft x0r=hround(1.5u-.5hair); x2=x4=x6=x8=.5w-.25u;
+@z
+@x
+y5=.5[y4,y6]; top y6r-bot y4r=vstem+eps; bot y8=-oo; y7=y9=.55[y6,y8];
+@y
+y5=.5[y4,y6]; top y6r-bot y4r=vstem+eps; bot y8r=-oo; y7=y9=.55[y6,y8];
+@z
+@x and also to delta
+y5+.1x_height=y7=.5[y6,y8]; bot y6=-oo;
+@y
+y5+.1x_height=y7=.5[y6,y8]; bot y6r=-oo;
+@z
+@x and also to phi
+top y1=x_height+oo; y2=y4=.5[y1,y3]; bot y3=-oo;
+@y
+top y1r=x_height+oo; y2=y4=.5[y1,y3]; bot y3r=-oo;
+@z
+
+-----------Here I draw the line with respect to further changes
+
+(I sincerely believe there won't be any more!)
+
+I absolutely guarantee that the TFM files will never change again.
+(Otherwise I would consider zeroing the depth of italic 7,
+which I admit is strange... we can live with it.)
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.eight b/Master/texmf-dist/doc/generic/knuth-errata/errata.eight
new file mode 100644
index 00000000000..f7ceafd9f69
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.eight
@@ -0,0 +1,610 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 1992}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting\/} between 15 March 1992 and the publication of the final
+printed versions of those books.
+Corrections made to the softcover version of {\sl The \TeX book\/} are
+the same as corrections to Volume~A\null. Corrections to the softcover
+version of {\sl The \slMF\kern1ptbook\/} are the same as corrections
+to Volume~C\null. Changes to Volume~B refer to the fourth printing
+(1991), which differs markedly from earlier printings because it includes
+all the revisions for \TeX3.0. Changes to Volume~D refer to the third
+printing (1991), which differs markedly from earlier printings because
+it includes all the revisions for \MF\kern1pt2.0. Changes to the mini-indexes
+and master indexes of Volumes B and~D are not shown here unless they are
+not obviously derivable from what has been shown.
+\looseness=-1
+
+% volume A
+
+\bugonpage A23, line 14 (9/1/92)
+
+\tenpoint\noindent
+a command and you type `|tex|' or `|run| |tex|' or something like that.)
+
+\bugonpage A53, line 23 (7/7/92)
+
+\tenpoint\noindent
+{\sl scientiarum imperialis petropolitan\ae\/}
+became {\sl Akademi\t\i a Nauk SSSR, Doklady}.
+
+\bugonpage A146, line 2 from the bottom (2/25/93)
+
+|$\bigl|\|| |\||x|\||-|\||y|\|| \bigr|\||$|\hskip1.25in
+  $\bigl\vert\vert x\vert-\vert y\vert\bigr\vert$
+
+\bugonpage A149, lines 3--5 (2/25/93)
+
+\noindent
+example, we used |\bigl| and |\bigr| to produce $\bigl\vert\vert x\vert-
+\vert y\vert\bigr\vert$ in one of the previous illustrations; |\left| and
+|\right| don't make things any bigger than necessary, so
+`|$\left|\||\left|\||x\right|\||-\left|\||y\right|\||\right|\||$|'
+yields only `$\left\vert
+ \left\vert x\right\vert -\left\vert y\right\vert \right\vert$'.\cutpar
+
+\bugonpage A158, line 18 from the bottom (2/25/93)
+
+\ninepoint
+are four possibilities for each of these fields.
+A field can be
+
+\bugonpage A282, line 9 from the bottom (7/8/92)
+
+\ninepoint\noindent
+category~4) are intercepted by the alignment
+process, en route to \TeX's stomach, so\cutpar
+
+\bugonpage A293, new paragraph after line 15 (4/9/92)
+
+\ninepoint
+\textindent{$\bull$}|\unhbox|\<8-bit number>, |\unhcopy|\<8-bit number>.\enskip
+The specified box register must be void. Nothing happens.
+
+\bugonpage A309, line 23 (7/7/92)
+
+\ninepoint\noindent
+|petropolitan\ae\/} became {\sl Akademi\t\i a Nauk SSSR, Doklady}.|
+
+\bugonpage A320, line 11 (1/26/93)
+
+\ninepoint
+\ansno17.12:
+|$\bigl(x+f(x)\bigr) \big/ \bigl(x-f(x)\bigr)$|. \ Notice especially the\cutpar
+
+\bugonpage A349, second line from the bottom (7/8/92)
+
+\ninepoint\noindent
+expand to a ^\<number> en route to \TeX's
+``stomach''; |\multiply| wouldn't work, because\cutpar
+
+\bugonpage A358, bottom line (2/3/93)
+
+\ninepoint\noindent
+it is easy to define ^|\ldots| and ^|\cdots| macros that
+give the proper spacing in most\cutpar
+
+\bugonpage A370, lines 28 and 29 (9/1/92)
+
+\def\Russiantt#1{{\tt\hbox to.5em{\hss\eighttt\char#1\hss}}}
+\ninepoint\noindent
+example, if \TeX\ is implemented for
+a purely ^{Cyrillic} ^^{Russian} keyboard, the letter `\Russiantt5' should be
+assigned to code \oct{160} and `\Russiantt{`T}' to code \oct{164}, so that
+`\Russiantt5\Russiantt{`T}' still means `|pt|'; or else control\cutpar
+
+\bugonpage A377, lines 17--24 (5/4/92)
+
+\ninepoint
+\begintt
+\def\sanswitch{\let\n@xt\endsanity \ifx\next\endsanity
+  \else\ifcat\noexpand\next\stoken\aftergroup\space\let\n@xt=\eat
+   \else\ifcat\noexpand\next\bgroup\aftergroup{\let\n@xt=\eat
+    \else\ifcat\noexpand\next\egroup\aftergroup}\let\n@xt=\eat
+     \else\let\n@xt=\copytok\fi\fi\fi\fi \n@xt}
+\def\eat{\afterassignment\sanitize \let\next= }
+\long\def\copytok#1{\ifcat\noexpand#1\relax\aftergroup\noexpand\fi
+  \ifcat\noexpand#1\noexpand~\aftergroup\noexpand\fi
+\endtt
+
+\bugonpage A455, line 25 (2/26/93)
+
+\ninepoint\noindent
+rent language'' is set equal to |\language|. Whenever a
+character is added to the cur-\cutpar
+
+\bugonpage A459, second line of entry for ampersand (3/22/92)
+
+\eightpoint\indent\qquad
+{\it231--248}, $\underline{282}$, {\it339}, 344, 385--386, 428.
+
+\bugonpage A461, right column (2/19/93)
+
+\eightpoint
+\newbox\astbox \setbox\astbox=\hbox to0pt{\hss\lower1pt\hbox{*}}
+\def\prim#1{\par\indent\copy\astbox{\tt\char`\\#1}}
+\prim{chardef}, 44, 121, 155, 210, 214, 215, 271,\par
+\indent\qquad $\underline{277}$, 336, {\it343}, {\it345}, {\it356}, 452.\par
+\indent\<chardef token>, $\underline{271}$, 283, 286, 289.
+
+\bugonpage A467, left column (2/25/93)
+
+\eightpoint
+Greek, 127--128, 137, 156, 164, 319,\par
+\indent\qquad 358, 430, 434.
+
+\bugonpage A470, left column (2/25/93)
+
+\eightpoint
+margins, {\sl see\/} |\hoffset|, |\hsize|, |\narrower|.
+
+\bugonpage A471, left column (2/19/93)
+
+\eightpoint
+\prim{mathchardef}, 155, 199, 214, 215, 271,\par
+\indent\qquad 277, 289, 336, {\it358}, {\it394}.\par
+\indent\<mathchardef token>, $\underline{271}$, 289.
+
+\bugonpage A474, right column (3/22/92)
+
+\eightpoint
+pound sterling, 54, {\it339}, 428.
+
+\bugonpage A477, right column (3/22/92)
+
+\eightpoint
+sterling, 54, {\it339}, 428.
+
+\bugonpage A480, left column (4/9/92)
+
+\eightpoint
+\prim{unhbox}, 120, 283, $\underline{285}$, 293, {\it354}, {\it356},
+  {\it399}.\par
+\prim{unhcopy}, 120, 283, $\underline{285}$, 293, {\it353}.
+
+\bugonpage A481, left column (2/25/93)
+
+\eightpoint
+whatsits, 95, 110, 157, 226--229, 455.
+
+\bugonpage A483, lines 15--21 (2/25/93)
+
+{\tt P.O. Box 869\par
+Santa Barbara, CA 93102-0869 USA.\par
+|}|}
+\smallskip\noindent
+Don't delay, write today! That number again is
+
+\smallskip
+{\obeylines
+\TeX\ Users Group
+P.O. Box 869
+Santa Barbara, CA 93102-0869 USA.
+}
+
+% volume B
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage B2, line 10 from the bottom (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]3.1415\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B89, line 12 (2/27/93)
+
+\tenpoint
+\noindent\hskip10pt
+In horizontal mode, the \\{prev\_graf} field is used for initial language data.
+
+\bugonpage B89, line 20 (2/27/93)
+
+\ninepoint
+\noindent\hskip20pt
+\\{pg\_field}, \\{ml\_field}: \\{integer}; \  \\{aux\_field}: \\{memory\_word};
+\par
+\noindent [Also delete the definitions of \\{lhmin} and \\{rhmin}, lines
+32 and 33.]
+
+\bugonpage B90, line 13 (2/27/93)
+
+\ninepoint
+\noindent\hskip10pt
+$\\{prev\_depth}\gets\\{ignore\_depth}$; \ $\\{mode\_line}\gets0$; \
+$\\{prev\_graf}\gets0$;
+
+\bugonpage B91, top three lines (2/27/93)
+
+\ninepoint
+\noindent\hskip20pt
+{\bf if\/} $m=\\{hmode}$ {\bf then if\/} $\\{nest}[p].\\{pg\_field}\ne
+ \oct{40600000}$ {\bf then}\par\noindent\hskip40pt
+{\bf begin} \\{print}({\tt\char`\"\](language\char`\"}); \
+ \\{print\_int}(\\{nest}[$p$].\\{pg\_field} {\bf mod} \oct{200000});\par
+\noindent\hskip40pt
+ \\{print}({\tt\char`\":hyphenmin\char`\"}); \
+ \\{print\_int}(\\{nest}[$p$].\\{pg\_field} {\bf div} \oct{20000000}); \
+ \\{print\_char}({\tt\char`\",\char`\"});\par\noindent\hskip40pt
+\\{print\_int}((\\{nest}[$p$].\\{pg\_field} {\bf div} \oct{200000})
+ {\bf mod} \oct{100}); \ \\{print\_char}({\tt\char`\")\char`\"});
+
+\bugonpage B344, lines 21 and 22 (2/27/93)
+
+\tenpoint\noindent\hskip10pt
+This code assumes that a \\{glue\_node} and a \\{penalty\_node} occupy the
+same number of \\{mem}~words.
+
+\bugonpage B344, line 30 (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+$\\{link}(\\{tail})\gets\\{new\_param\_glue}(\\{par\_fill\_skip\_code})$; \
+ $\\{init\_cur\_lang}\gets\\{prev\_graf}$ {\bf mod} \oct{200000};\par
+\noindent\hskip10pt
+$\\{init\_l\_hyf}\gets\\{prev\_graf}$ {\bf div} \oct{20000000}; \
+$\\{init\_r\_hyf}\gets(\\{prev\_graf}$ {\bf div} \oct{200000}) {\bf mod}
+ \oct{100}; \
+\\{pop\_nest};
+
+\bugonpage B353, line 4 (2/27/93)
+
+\tenpoint\noindent\hskip10pt
+Kern nodes do not disappear at a line break unless they are \\{explicit}.
+
+\bugonpage B353, lines 15 and 16 (2/27/93)
+
+\ninepoint\noindent\hskip20pt
+\\{math\_node}: $\\{break\_width}[1]\gets\\{break\_width}[1]-\\{width}(s)$;\par
+\noindent\hskip20pt
+\\{kern\_node}: {\bf if\/} $\\{subtype}(s)\ne\\{explicit}$
+  {\bf then goto} \\{done}\par\noindent\hskip30pt
+{\bf else} $\\{break\_width}[1]\gets\\{break\_width}[1]-\\{width}(s)$;
+
+\bugonpage B354, lines 6 and 7 (2/27/93)
+
+\tenpoint\noindent
+will be the background
+plus $l_1$, so the length from \\{cur\_p} to \\{cur\_p} should be
+$\gamma+l_0+l_1-l$.
+If the post-break text of the discretionary is empty, a break may also
+discard~$q$; in that unusual case we subtract the length of~$q$ and any
+other nodes that will be discarded after the discretionary break.
+
+\bugonpage B354, line 18 (2/27/93)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin} $\langle\,$Add the width of node $s$ to \\{break\_width}{\sevenrm
+  \kern.5em842}$\,\rangle$;
+
+\bugonpage B354, line 22 (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{post\_break}(\\{cur\_p})=\\{null}$ {\bf then}
+  $s\gets\\{link}(v)$;\quad$\{\,$nodes may be discardable after the break$\,\}$
+
+\bugonpage B355, top line (2/27/93)
+
+\ninepoint\noindent
+{\tenbf842.\quad}$\langle\,$Add the width of node $s$ to
+ \\{break\_width}{\sevenrm\kern.5em842}$\,\rangle\equiv$
+
+\bugonpage B355, lines 9--14 (2/27/93)
+
+\ninepoint\noindent\hskip20pt
+$\\{hlist\_node},\\{vlist\_node},\\{rule\_node},\\{kern\_node}$:
+    $\\{break\_width}[1]\gets\\{break\_width}[1]+\\{width}(s)$;\par
+\noindent\hskip20pt
+{\bf othercases} \\{confusion}({\tt\char`\"disc2\char`\"})\par
+\noindent\hskip20pt
+{\bf endcases}
+
+\bugonpage B364, line 10 (2/27/93)
+
+\tenpoint\noindent
+a glue node, penalty node, explicit kern node, or math node.
+
+\bugonpage B366, line 11 from the bottom (2/27/93)
+
+\ninepoint\noindent
+\\{kern\_node}: {\bf if\/} $\\{subtype}(\\{cur\_p})=\\{explicit}$
+ {\bf then} \\{kern\_break}\par\noindent\hskip10pt
+{\bf else} $\\{act\_width}\gets\\{act\_width}+\\{width}(\\{cur\_p})$;
+
+\bugonpage B367, line 21 (2/27/93)
+
+\ninepoint\noindent\hskip20pt
+{\bf else if\/} \\{precedes\_break}(\\{prev\_p}) {\bf then}
+ $\\{try\_break}(0,\\{unhyphenated})$\par\noindent\hskip20pt
+{\bf else if\/} $(\\{type}(\\{prev\_p})=\\{kern\_node})\land
+ (\\{subtype}(\\{prev\_p})\ne\\{explicit})$ {\bf then}
+ $\\{try\_break}(0,\\{unhyphenated})$;
+
+\bugonpage B372, lines 12 and 13 (2/27/93)
+
+\ninepoint\noindent\hskip20pt
+{\bf if\/} $\\{type}(q)=\\{kern\_node}$ {\bf then}\par\noindent\hskip30pt
+{\bf if\/} $\\{subtype}(q)\ne\\{explicit}$ {\bf then goto} \\{done1};
+
+\bugonpage B376, line 3 from the bottom (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+$\\{cur\_lang}\gets\\{init\_cur\_lang}$; \
+$\\{l\_hyf}\gets\\{init\_l\_hyf}$; \
+$\\{r\_hyf}\gets\\{init\_r\_hyf}$;
+
+\bugonpage B377, lines 11 and 12 (2/27/93)
+
+\ninepoint\noindent
+$\\{cur\_lang},\\{init\_cur\_lang}$: \\{ASCII\_code};\quad
+ $\{\,$current hyphenation table of interest$\,\}$\par\noindent
+$\\{l\_hyf},\\{r\_hyf},\\{init\_l\_hyf},\\{init\_r\_hyf}$: \\{integer};\quad
+ $\{\,$limits on fragment sizes$\,\}$
+
+\bugonpage B378, line 5 from the bottom, overriding earlier change (2/27/93)
+
+\ninepoint\noindent\hskip30pt
+{\bf else if} $(\\{type}(s)=\\{kern\_node})\land(\\{subtype}(s)=\\{normal})$
+ {\bf then}\par\noindent\hskip50pt
+{\bf begin} $\\{hb}\gets s$; \ $\\{hyf\_bchar}\gets\\{font\_bchar}[\\{hf}]$; \
+ {\bf end}\par\noindent\hskip40pt
+{\bf else goto} \\{done3};
+
+
+\bugonpage B394, lines 12 and 13 (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+{\bf var} $n$: $0\to64$;\quad$\{\,$length of current word; not always
+  a \\{small\_number}$\,\}$\par\noindent\hskip20pt
+$j$: $0\to64$;\quad$\{\,$an index into \\{hc}$\,\}$
+
+\bugonpage B404, line 21 (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+{\bf var} $k,l$: $0\to64$;\quad$\{\,$indices into \\{hc} and \\{hyf};
+                  not always in \\{small\_number} range$\,\}$
+
+\bugonpage B460, lines 21 and 22 (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+\\{push\_nest}; \ $\\{mode}\gets\\{hmode}$; \ $\\{space\_factor}\gets1000$; \
+ \\{set\_cur\_lang}; \ $\\{clang}\gets\\{cur\_lang}$;\par\noindent\hskip10pt
+$\\{prev\_graf}\gets(\\{norm\_min}(\\{left\_hyphen\_min})\ast\oct{100}+
+ \\{norm\_min}(\\{right\_hyphen\_min}))\ast\oct{200000}+\\{cur\_lang}$;
+
+\bugonpage B492, line 6 from the bottom (2/27/93)
+
+\ninepoint\noindent\hskip10pt
+\\{unsave}; \ $\\{prev\_graf}\gets\\{prev\_graf}+3$;\par\noindent\hskip10pt
+\\{push\_nest}; \ $\\{mode}\gets\\{hmode}$; \ $\\{space\_factor}\gets1000$; \
+ \\{set\_cur\_lang}; \ $\\{clang}\gets\\{cur\_lang}$;\par\noindent\hskip10pt
+$\\{prev\_graf}\gets(\\{norm\_min}(\\{left\_hyphen\_min})\ast\oct{100}+
+ \\{norm\_min}(\\{right\_hyphen\_min}))\ast\oct{200000}+\\{cur\_lang}$;
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\bugonpage C151, line 11 from the bottom (6/26/93)
+
+\ninepoint\indent
+\qquad   scaled $1.42(1+\max(-\\{pen\_lft},\\{pen\_rt},\\{pen\_top},
+  -\\{pen\_bot}))$
+
+\bugonpage C262, line 15 (6/26/93)
+
+\ninepoint\noindent
+|string base_name, base_version; base_name="plain"; base_version="2.71";|
+
+\bugonpage C262, line 29 (6/26/93)
+
+\ninepoint\noindent
+|def |^|gobble|| primary g = enddef; def |^|killtext|| text t = enddef;|
+
+\bugonpage C271, bottom line (6/26/93)
+
+\ninepoint\noindent
+| culldraw p enddef;|
+
+\bugonpage C272, three new lines for top of page (6/26/93)
+
+{\ninepoint\parindent=0pt
+|def |^|culldraw|| expr p = addto pic_ doublepath p.t_ withpen currentpen;|\par
+| cull pic_ dropping(-infinity,0) withweight default_wt_;|\par
+| addto_currentpicture also pic_; pic_:=nullpicture; killtext enddef;|\par
+}
+
+\bugonpage C272, replacement for former line 5 (6/26/93)
+
+\ninepoint\noindent
+|  (cut_ scaled (1+max(-pen_lft,pen_rt,pen_top,-pen_bot))|
+
+\bugonpage C296, line 24 (2/3/93)
+
+\ninepoint\noindent
+the definition of |rp| is changed to `|]..tension 4..|',
+and if `|scaled|~|5pt|' is inserted\cutpar
+
+\bugonpage C299, line 3 (5/15/92)
+
+\ninepoint\noindent
+a Bernshte{\u\i}n polynomial of order $n-1$.)
+
+\bugonpage C347, left column (5/15/92)
+
+\eightpoint
+Bernshte{\u\i}n, Serge{\u\i} \thinspace Natanovich, 14.
+
+\bugonpage C348, left column (6/26/93)
+
+\eightpoint
+|culldraw|, {\it271}, $\underline{272}$.
+
+\bugonpage C350, left column (6/26/93)
+
+\eightpoint
+exponential, {\sl see\/} |mexp|.
+
+\bugonpage C352, left column (6/26/93)
+
+\eightpoint
+|killtext|, $\underline{262}$, {\it 272}.
+
+\bugonpage C352, right column (6/26/93)
+
+\eightpoint
+logarithm, {\sl see\/} |mlog|.
+
+\bugonpage C361, lines 14 and 15 (2/25/93)
+
+P.O. Box 869\par
+Santa Barbara, CA 93102-0869 USA.
+
+
+% Volume D
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Dxiv, line 13 (4/19/96)
+
+\noindent preprocessor converts these into numeric constants that are
+256 or more. This\cutpar
+
+\bugonpage Dxiv, line $-1$ (4/19/96)
+
+\ninepoint\noindent This file contains one line per string, starting with
+string number 256, then number 257,\cutpar
+
+\bugonpage Dxv, lines 10 and 11 (4/19/96)
+
+\ninepoint\noindent
+In this case, occurrences of |""| in the |WEB| program will be replaced by
+256; occurrences of |"This longer string"| will be replaced by 257.
+The symbol |@$| stands for the numeric\cutpar
+
+\hsize=35pc
+\bugonpage D2, line $-17$ (8/7/98)
+
+\def\RQ/{{\char'23}} % right quote in a string
+\ninepoint\noindent
+{\bf define} $\\{banner}\equiv\hbox{\tt\RQ/This\]is\]METAFONT,\]%
+   Version\]2.7182\RQ/}$\quad$\{\,$printed when \MF\ starts$\,\}$
+
+\bugonpage D50, line 26 (8/7/98)
+
+\ninepoint\noindent
+\quad{\bf if\/} $b>0$ {\bf then}
+
+\bugonpage D138, line 14 from the bottom (3/6/95)
+
+\tenpoint
+\textindent{$2'$)} Let $Z_k^{(j+1)}={1\over2}(Z_k^{(j)}+Z_{k+1}^{(j)})$, for
+$1\le k\le n-j$, for $1\le j<n$.
+
+\bugonpage D190, D191, D194, D195 (6/26/93)
+
+\noindent[Several changes to the code in sections 415, 416, 424, and 425
+were made to \MF\ version 2.71 in July~1991, too numerous to mention here.
+They are documented in file {\tt mf84.bug} as bug number 560. We also
+delete lines 4 and~5 of page D194.]
+
+\bugonpage D216, line 10 from the bottom (7/15/92)
+
+\tenpoint\noindent
+will be offset by $w_1$ or $w_2$, unless its slope drops to zero
+en route to the eighth octant; in the latter\cutpar
+
+\bugonpage D289, lines 9 and 10 (6/26/93)
+
+\ninepoint\noindent\hskip20pt
+$p\gets\\{dep\_list}(p)$; \ $r\gets\\{inf\_val}$;\par\noindent\hskip20pt
+{\bf repeat if\/} $\\{value}(\\{info}(p))\ge\\{value}(r)$ {\bf then}
+
+\bugonpage D296, lines 8 and 9 from the bottom (9/13/98)
+
+\ninepoint\noindent[Delete these spurious lines.]
+
+\bugonpage D297, mini-index (6/6/98)
+
+\eightpoint the meaning of {\it loc\/} should be `macro'
+
+\bugonpage D310, line 7 (8/7/98)
+
+\ninepoint\noindent
+\quad{\bf if\/} $(\\{loc}=k+1)\land(\\{length}(\\{buffer}[k])=1)$
+ {\bf then} $\\{cur\_mod}:=\\{buffer}[k]$
+
+\bugonpage D363, lines 10 and 11 (3/1/95)
+
+\ninepoint\noindent
+\quad {\bf begin if\/} $(\\{max\_c}[\\{dependent}]$ {\bf div}
+ $\oct{10000}\ge\\{max\_c}[\\{proto\_dependent}])$ {\bf then}
+ $t\gets\\{dependent}$
+
+\bugonpage D512, line 13 (11/23/98)
+
+\ninepoint\noindent
+\quad \\{print\_int}(\\{round\_unscaled}(\\{internal}[\\{year}])); \
+ \\{print\_char}(|"."|);
+
+\bugonpage D518, insert new material between lines 7 and 8 (3/20/95)
+
+\ninepoint\noindent
+\quad {\bf while} $\\{input\_ptr}>0$ {\bf do}\par\noindent
+\qquad {\bf if\/} \\{token\_state} {\bf then} \\{end\_token\_list}
+  {\bf else} \\{end\_file\_reading};\par\noindent
+\quad {\bf while} $\\{loop\_ptr}\ne\\{null}$ {\bf do} \\{stop\_iteration};
+
+\bugonpage D518, line 18 (3/20/95)
+
+\ninepoint\noindent
+\qquad $\\{loop\_ptr}\gets\\{cond\_ptr}$; \
+  $\\{cond\_ptr}\gets\\{link}(\\{cond\_ptr})$; \
+  $\\{free\_node}(\\{loop\_ptr},\\{if\_node\_size})$;
+
+\bugonpage D546, left column (4/11/96)
+
+\eightpoint
+Stern, Moritz Abraham: \ 526.
+
+% volume E
+\hsize=29pc
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+
+\bye
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.eleven b/Master/texmf-dist/doc/generic/knuth-errata/errata.eleven
new file mode 100644
index 00000000000..64d9f8ab457
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.eleven
@@ -0,0 +1,317 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\def\curl{\mathop{\rm curl}}
+\def\cycle{{\rm cycle}}\indent
+\def\dashto{\mathrel{\hbox{-\thinspace-\kern-.05em}}}
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 2001}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all substantial corrections made to {\sl Computers
+\& Typesetting\/} between the first ``Millennium edition'' of 2000 and the
+second such edition, which appeared late in 2001.
+(More precisely, it lists errors to the 16th, 7th, 6th, 4th, and 5th
+printings of Volumes A, B, C, D, and E, respectively, that were corrected
+in the 17th, 8th, 7th, 5th, and 6th printings.)
+Changes to the mini-indexes
+and master indexes of Volumes B, D, and~E are not shown here unless they are
+not obviously derivable from what has been shown.
+\looseness=-1
+
+% volume A
+
+\bugonpage A16, line 7 from the bottom (06/30/01)
+
+\font\magnifiedfiverm=cmr5 at 10pt
+\tenpoint\indent
+Ten-point type is different from%
+  \magnifiedfiverm\ magnif{}ied f{}ive-point type.
+
+\bugonpage A17, line 7 (06/30/01)
+
+\ninepoint\indent
+fications that grow in geometric ratios---something like equal-tempered
+tuning\cutpar
+
+\bugonpage A51, lines 18--20 (06/30/01)
+
+\tenpoint\kern-6pt\noindent
+$$\openup1pt\halign{\indent#\hfil\cr
+|ff| yields ff\thinspace;$\!$\quad |fi| yields fi\thinspace;$\!$\quad
+|fl| yields fl\thinspace;$\!$\quad
+|ffi| yields ffi\thinspace;$\!$\quad |ffl| yields ffl\thinspace;\cr
+|``| yields``\thinspace;\qquad |''| yields ''\thinspace;\qquad
+|!||`| yields !`\thinspace;\qquad |?||`| yields ?`\thinspace;\cr
+|--| yields --\thinspace;\qquad |---| yields ---\thinspace.\cr}$$
+
+\bugonpage A52, line 7 from the bottom (06/30/01)
+
+\tenpoint\kern-6pt\noindent
+$$\halign{\indent\hbox to 50pt{#\hfil}&\hbox to 35pt{#\hfil}&#\hfil\cr
+|\ae,\AE|&\ae,\thinspace\AE&(Latin ligature and Scandinavian letter AE)\cr}$$
+
+\bugonpage A71, line 15 (06/30/01)
+
+\tenpoint\indent
+One of the interesting things that can happen when glue stretches and\cutpar
+
+\bugonpage A180, line 20 (06/30/01)
+
+\ninepoint\indent
+Challenge number 5:\enspace
+$\qquad\tenmath k=1.38065\times10^{-16}\rm\,erg\,K^{-1}$.
+
+\bugonpage A254, line 12 from the bottom becomes two lines (04/09/01)
+
+\ninepoint\noindent
+\begintt
+\output={\unvbox255
+  \ifnum\outputpenalty<10000 \penalty\outputpenalty\fi}
+\endtt
+
+\bugonpage A292, lines 13--16 (06/30/01)
+
+\def\s{\hskip0pt plus1pt}
+\ninepoint\textindent{$\bull$}|\mathchoice|\s
+$\langle$filler$\rangle$\s|{|\s$\langle$math mode material$\rangle$\s|}|\s
+$\langle$filler$\rangle$\s|{|\s$\langle$math mode material$\rangle$\s|}|\break
+$\langle$filler$\rangle$|{|$\langle$math mode material$\rangle$|}|
+$\langle$filler$\rangle$|{|$\langle$math mode material$\rangle$|}|.
+Four math lists, which are defined as in the
+second alternative of a \<math field>, are
+recorded in a ``choice item'' that is appended to the current list.
+
+\bugonpage A306, line 7 (06/30/01)
+
+\ninepoint\noindent
+instead of a shelf{\kern0pt}ful.
+In fact, the latter idea---to
+insert an italic correction---is prefer-\cutpar
+
+\bugonpage A323, line 12 from the bottom (06/30/01)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss18.31.\enspace}%
+|$k=1.38065\times10^{-16}\rm\,erg\,K^{-1}$|.
+
+\bugonpage A451, line 15 (01/30/01)
+
+\tenpoint\noindent
+{\sl Connecticut Yankee\/} come out with only nine or
+ten bad hyphens:
+
+\bugonpage A451, line 23 (01/30/01)
+
+\tenpoint\noindent\begintt
+  mo-er-der-mohren-mut-ter-mar-mor-mon-u-menten-macher.
+\endtt
+
+\bugonpage A454, lines 23--30 (06/30/01)
+
+\begingroup
+\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
+\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
+\ddanger If a suitable starting letter is found, let it be in font~$f$.
+Hyphenation is abandoned unless the |\hyphenchar| of~$f$ is a number
+between 0 and~255, inclusive.
+If this test is passed, \TeX\ continues to scan forward
+until coming to something that's not one of the following three
+``admissible items'': (1)~a character in font~$f$ whose |\lccode|
+is nonzero; (2)~a ligature formed entirely from characters of type~(1);
+(3)~an implicit kern. The first inadmissible item terminates this part of
+the process; the trial word consists of all the letters found in admissible
+items. Notice that all of these letters are in font~$f$.
+\par\endgroup
+
+\bugonpage A461, right column (07/08/01)
+
+\eightpoint\noindent
+\llap{*}|\char|, {\it 43--45}, 76, 86, 155, 283, $\underline{286}$,
+
+\bugonpage A466, left column (07/09/01)
+
+\eightpoint\noindent
+\llap{*}|\floatingpenalty|, $\underline{123}$--$\underline{124}$,
+ 272, 281, {\it 363}.
+
+\bugonpage A473, left column (06/30/01)
+
+\eightpoint\noindent
+orphans, {\sl see\/} widow words.
+
+% volume B
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\hsize=35pc
+
+\bugonpage B8, line 2 (05/04/01)
+
+\tenpoint\noindent
+statements will be meaningful. We insert the label
+`\\{exit}' just before the `{\bf end}' of a procedure in\cutpar
+
+\bugonpage B30, line $-4$ (05/04/01)
+
+\ninepoint\noindent
+\quad{\bf begin} \\{update\_terminal};\quad$\{\,$now the user sees
+ the prompt for sure$\,\}$
+
+\bugonpage B84, lines 22 and 27 (05/04/01)
+
+\ninepoint\noindent
+\quad$\\{ignore}=9$\quad$\{\,$characters to ignore ( |^^@| )$\,\}$\par
+\noindent
+\quad$\\{active\_char}=13$\quad$\{\,$characters that invoke
+ macros ( |~| )$\,\}$
+
+\bugonpage B280, lines 23 and 24 (04/08/01)
+
+\tenpoint\noindent
+or unset nodes; in particular, each mlist item appears in the
+variable-size part of \\{mem}, so the \\{type} field is always present.
+
+\bugonpage B382, line 6 (01/01/01)
+
+\tenpoint\noindent
+between `fl' and `y', then $m=2$, $t=2$, and $y_1$ will
+be a ligature node for `fl' followed by an\cutpar
+
+\bugonpage B386, line 11 (04/08/01)
+
+\ninepoint\noindent
+\quad$\\{qi}(2),\\{qi}(6)$: {\bf begin} $\\{cur\_r}\gets\\{rem\_byte}(q)$;%
+ \quad$\{\,$\||=:|, \||=:>|$\,\}$
+
+\bugonpage B475, line 12 (07/01/01)
+
+\ninepoint\noindent
+\qquad{\bf end};\quad$\{\,$now we are in vertical mode,
+ working on the list that will contain the display$\,\}$
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\ddashto{\mathrel{\hbox{-\thinspace-\thinspace-\kern-.05em}}}
+\def\tension{\mathop{\rm tension}}
+\def\controls{\mathop{\rm controls}}
+\def\and{\,{\rm and}\,}
+
+\bugonpage C204, line 3 from the bottom (07/08/01)
+
+\ninepoint\noindent
+slightly. If $\\{autorounding}>1$,
+you get even more changes: Paths are perturbed slightly\cutpar
+
+\bugonpage C238, lines 9 and 8 from the bottom (07/08/01)
+
+\ninepoint\noindent
+tance is ${\rm length}(z_4-z_1)$. But there's a slicker solution:
+Just calculate
+$$\hbox{abs ypart$((z_1-z_2)\mathbin{\rm rotated}-{\rm angle}(z_3-z_2))$.}$$
+
+\bugonpage C313, bottom line (06/30/01)
+
+\rightline{\eightss--- LA ROCHEFOUCAULD, {\eightssi Maximes\/}\enspace(1665)}
+
+\bugonpage C352, left column (06/30/01)
+
+\eightpoint\noindent
+La Rochefoucauld, Fran\c cois VI, 313.
+
+\bugonpage C357, right column (07/08/01)
+
+\eightpoint\noindent
+\llap{*}|true|, 55, {\it64\/}--{\it65}, 170, 210.
+
+% Volume D
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\hsize=35pc
+
+\bugonpage D8, line 2 (05/04/01)
+
+\tenpoint\noindent
+statements will be meaningful. We insert the label
+`\\{exit}' just before the `{\bf end}' of a procedure in\cutpar
+
+\bugonpage D28, line $-8$ (05/04/01)
+
+\ninepoint\noindent
+\quad{\bf begin} \\{update\_terminal};\quad$\{\,$now the user sees
+ the prompt for sure$\,\}$
+
+\bugonpage D101, line 21 (07/08/01)
+
+\ninepoint\noindent
+\quad{\bf define} $\\{subscr\_head\_loc}(\hbox{\tt\#})\equiv\hbox{\tt\#}+1$
+\quad$\{\,$where \\{value}, \\{subscr\_head}, and \\{attr\_head} are$\,\}$
+
+\bugonpage D180, lines 22 and 23 (01/26/01)
+
+\tenpoint\noindent
+$(y,-x)$ will appear in node~$p$. Similarly, a fourth-octant
+transformation will have been applied after the transition, so
+we will have $\\{x\_coord}(q)=\hbox{$-x$}$ and $\\{y\_coord}(q)=y$.
+
+\bugonpage D196, lines 7 and 8 (01/26/01)
+
+\tenpoint\noindent
+where $x'(t)\ge0$ we have $\\{right\_type}=%
+\\{first\_octant}$ or $\\{right\_type}=\\{eighth\_octant}$; in regions where
+$x'(t)\le0$,
+we have $\\{right\_type}=\\{fifth\_octant}$ or $\\{right\_type}=\\{fourth%
+\_octant}$.
+
+\bugonpage D511, line 17 (07/03/01)
+
+\tenpoint\noindent
+from appearing again.
+
+% volume E
+\hsize=29pc
+
+\newbox\shorthyf \setbox\shorthyf=\hbox{-\kern-.05em}
+\mathchardef\period=`\.
+{\catcode`\-=\active \global\def-{\copy\shorthyf\mkern3.9mu}
+ \catcode`\.=\active \global\def.{\period\mkern3mu}}
+\def\8#1{\mathrel{\mathcode`\.="8000 \mathcode`\-="8000
+  #1\unkern}} % `..' and `--'
+
+\bugonpage E9, line 9 (07/03/01)
+
+\tenpoint\indent
+|[92] [123] [124]) ) )|
+
+\bye
+
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.five b/Master/texmf-dist/doc/generic/knuth-errata/errata.five
new file mode 100644
index 00000000000..4e2982f109a
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.five
@@ -0,0 +1,1108 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 1989}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting}, Volumes \hbox{A--E}, between 20 February 1989 and
+30 September 1989 (when \TeX\ Version 3.0 and \MF\ Version 2.0 were
+fully defined). Corrections made to
+the softcover version of {\sl The \TeX book\/} are the same as corrections to
+Volume~A\null. Corrections to the softcover version of {\sl The
+\slMF\kern1ptbook\/} are the same as corrections to Volume~C\null.
+Some of these corrections have already been made in reprintings
+of the books. Several minor changes
+to Volumes A~and~C are not shown here because they simply
+make room for the more substantive changes needed to describe the new
+features of \TeX\ Version 3.0 and \MF\ Version 2.0. Hundreds of
+changes will soon be made to Volumes B~and~D because of the upgrades
+to \TeX\ and \MF\/; it will unfortunately be impossible to document all of those
+changes. Therefore, readers who need up-to-date information on the \TeX\ and
+\MF\ programs should refer to the |WEB| source files until new
+printings of Volumes B~and~D are issued.
+
+% volume A
+
+\buginvol A, in general (9/23/89)
+
+\ninepoint\noindent
+[Change `127' to `255' and `128' to `256' in contexts referring to character
+codes. This happens on pages 37(twice), 39, 41, 43, 44(twice), 48, 93, 154,
+277, 305(twice), 308(twice), 313, and 343. Also change `7-bit' to `8-bit' on
+pages 214 and 277.]
+
+\bugonpage A23, line 16 (9/23/89)
+
+|This is TeX, Version 3.0 (preloaded format=plain 89.7.15)|
+
+\bugonpage A34, new copy for bottom of page (9/23/89)
+
+\ddanger If you use \TeX\ format packages designed by others, your
+error messages may involve many inscrutable two-line levels of macro
+context. By setting ^|\errorcontextlines||=0| at the beginning of your file,
+you can reduce the amount of information that is reported;
+\TeX\ will show only the top and bottom pairs of context lines
+together with up to |\errorcontextlines| additional two-line items. \ (If
+anything has thereby been omitted, you'll also see `|...|'.) \ Chances
+are good that you can spot the source of an error even when most of a
+large context has been suppressed; if not, you can say
+`|I\errorcontextlines=100\oops|' and try again. \ (That will usually
+give you an undefined control sequence error and plenty of context.) \
+Plain \TeX\ sets |\errorcontextlines=5|.
+
+\bugonpage A45, lines 9--15 (9/23/89)
+
+\ninepoint\noindent
+|^^| has an internal code between 64 and 127, \TeX\
+subtracts 64 from the code; if the code is between 0 and 63, \TeX\
+adds~64. Hence code 127 can be typed |^^?|, and
+the dangerous bend sign can be obtained by saying
+|{\manual^^?}|. However, you must change the category code of character
+127 before using it, since this character ordinarily has category~15
+(^{invalid}); say, e.g., |\catcode`\^^?=12|.
+^^{double hat} ^^{hat hat}
+The |^^| notation is different from |\char|, because |^^| combinations are
+like single characters; for example, it would not be permissible to say
+|\catcode`\char127|, but |^^| symbols can even be used as letters within
+control words.
+
+\bugonpage A45, new copy before line 20 (9/23/89)
+
+\danger There's also a special convention in which |^^| is
+followed by {\sl two\/} ``lowercase hexadecimal digits,'' |0|--|9| or |a|--|f|.
+With this convention, all 256 characters are obtainable in a uniform
+way, from |^^00| to |^^ff|. Character 127 is |^^7f|.
+
+\noindent
+[Also remove one of the two dangerous bend signs on line 20.]
+
+\bugonpage A45, bottom paragraph and footnote (9/23/89)
+
+\ddanger People who install \TeX\ systems for use with non-American alphabets
+can make \TeX\ conform to any desired standard.  For example, suppose
+you have a ^{Norwegian keyboard} containing the letter {\tt\ae}, which
+^^{Scandinavian letters} ^^{foreign languages}
+comes in as code~241 (say). Your local format package should define
+|\catcode`|{\tt\ae}|=11|; then you could have control sequences like
+|\s|{\tt\ae}|rtrykk|. Your \TeX\ input files could be made readable by
+American installations of \TeX\ that don't have your keyboard, by
+substituting |^^f1| for character~241. \ (For example, the stated control
+sequence would appear as |\s^^f1rtrykk| in the file; your American
+friends should also be provided with the format that you used, with its
+|\catcode`^^f1=11|.) \ Of course you should also arrange your fonts
+so that \TeX's character 241 will print as {\ae}; and you should
+change \TeX's hyphenation algorithm so that it will do correct
+Norwegian hyphenation. The main point is that such changes are not
+extremely difficult; nothing in the design of \TeX\ limits it to the
+American alphabet. Fine printing is obtained by fine tuning to the
+language or languages being used.
+^^{keyboards, non-ASCII}
+
+\ddanger European languages can also be accommodated effectively with
+only a limited character set.
+For example, let's consider Norwegian again, but suppose that\parfillskip=0pt
+
+\noindent [Now continue with the text on line 11 of page 46.]
+
+\bugonpage A47, lines 9--21 (9/23/89)
+
+\ddanger If \TeX\ sees a superscript character (category 7) in any state,
+and if that character is followed by another identical character, and if
+those two equal characters are followed by a character of code
+$c<128$, then they
+are deleted and 64 is added~to or subtracted from the code~$c$.
+\ (Thus, |^^A| is
+replaced by a single character whose code is~1, etc., as explained earlier.) \
+However, if the two superscript characters are immediately followed by two
+of the lowercase hexadecimal digits |0123456789abcdef|, the
+four-character sequence is replaced by a single character having the
+specified hexadecimal code.
+The replacement is carried out also if such a trio or quartet of
+characters is encountered during steps (b) or~(c) of the control-sequence-name
+scanning procedure described above. After the replacement is made, \TeX\
+begins again as if the new character had been present all the time.
+If a superscript character is not the first of such a trio or quartet, it is
+handled by the following rule.
+
+\ddanger If \TeX\ sees a character of categories 1, 2, 3, 4, 6, 8, 11, 12,
+or~13,
+or a character of category~7 that is not the first of a special
+sequence as just
+described, it converts the character to a token by attaching the category
+code, and goes into state~$M$. This is the normal case; almost every
+nonblank character is handled by this rule.
+
+\bugonpage A48, line 15 (9/23/89)
+
+\ninepoint\noindent
+the input line
+`| $x^2$~  \TeX  ^^62^^6|'\thinspace?
+
+\bugonpage A54, third line from the bottom (9/23/89)
+
+\ninepoint\noindent
+For example, a well-designed \TeX\ font for ^{French}
+might well treat accents as lig-\cutpar
+
+\bugonpage A76, lines 3--5 from the bottom (9/23/89)
+
+\ninepoint\noindent
+\TeX\ does not assign any value to
+|\sfcode'042|.
+
+\bugonpage A107, new copy for top of page (9/23/89)
+
+\ddanger If you want to avoid overfull boxes at all costs without
+trying to fix them manually, you might be tempted to set
+|tolerance=10000|; this allows arbitrarily bad lines to be acceptable
+in tough situations. But infinite tolerance is a bad idea, because
+\TeX\ doesn't distinguish between terribly bad and preposterously
+horrible lines. Indeed, a tolerance of 10000 encourages \TeX\ to
+concentrate all the badness in one place, making one truly unsightly
+line instead of two moderately bad ones, because a single
+``write-off'' produces fewest total demerits according to the rules.
+There's a much better way to get the desired effect: \TeX\ has a
+parameter called ^|\emergencystretch| that is added to the assumed
+stretchability of every line when badness and demerits are computed,
+in cases where overfull boxes are otherwise unavoidable. If
+|\emergencystretch| is positive, \TeX\ will make a third pass over a
+paragraph before choosing the line breaks, when the first passes did
+not find a way to satisfy the ^|\pretolerance| and ^|\tolerance|.
+The effect of\/ |\emergencystretch| is to scale down the badnesses so
+that large infinities are distinguishable from smaller ones. By
+setting |\emergencystretch| high enough (based on |\hsize|) you can be
+sure that the |\tolerance| is never exceeded; hence overfull boxes
+will never occur unless the line-breaking task is truly impossible.
+
+\bugonpage A116, lines 11--15 (6/7/89)
+
+\danger If you have two or more |\topinsert| or |\pageinsert| commands in
+quick succession, \TeX\ may need to carry them over to several subsequent
+pages; but they will retain their relative order when they are
+carried over.  For example, suppose you have pages that are nine inches
+tall, and suppose you have already specified 4~inches of text for some
+page, say page~25.  Then suppose you make seven topinserts in a row, of%
+{\parfillskip=0pt\endgraf}\endgroup
+
+\bugonpage A125, lines 13--29 (9/23/89)
+
+\ddanger \looseness=-1
+When the best page break is finally chosen, \TeX\ removes everything after
+the chosen breakpoint from the bottom of the ``current page,'' and puts it
+all back at the top of the ``recent contributions.'' The
+chosen breakpoint itself is placed at the very top of the recent contributions.
+If it is a penalty item, the value of the penalty is recorded in
+^|\outputpenalty| and the penalty in the contribution list is changed
+to $10000$; otherwise |\outputpenalty| is set to 10000.
+The insertions that remain on the current page are of three kinds: For
+each class~$n$ there are unsplit insertions, followed possibly by
+a single split insertion, followed possibly by others. If
+^|\holdinginserts|$\null>0$, all insertions remain in place (so that
+they might be contributed again); otherwise they are all removed from
+the current page list as follows: The unsplit insertions
+are appended to |\box|$\,n$, with no interline glue between them. \
+(^{Struts} should be used, as in the |\vfootnote| macro of
+Appendix~B\null.) \
+If a split insertion is present, it is effectively |\vsplit| to the size
+that was computed previously in Step~4; the top part is treated as an
+unsplit insertion, and the remainder (if any) is converted to an insertion
+as if it had not been split. This remainder, followed by any other floating
+insertions of the same class, is held
+over in a separate place. \ (They will show up on the ``current page'' if
+^|\showlists| is used while an ^|\output| routine is active; the total
+number of such insertions appears in ^|\insertpenalties| during an
+|\output| routine.) %\
+Finally, the remaining items before the best break on the current page are put
+together in a |\vbox|\parfillskip=0pt
+
+\bugonpage A131, line 12 (9/22/89)
+
+\ninepoint\noindent
+work fine; but sometimes you want to have uniformity
+between different members of a\cutpar
+
+\bugonpage A155, lines 3--5 (9/23/89)
+
+\ninepoint\noindent
+when it encounters a character that
+is given explicitly as ^|\char|\<number>.
+
+\bugonpage A214, lines 19--24 (9/23/89)
+
+\ninepoint
+\textindent\bull |\the|\<special register>, where \<special register> is
+one of the integer quantities ^|\prevgraf|, ^|\deadcycles|, ^|\insertpenalties|,
+^|\inputlineno|, ^|\badness|,
+or ^|\parshape| (denoting only the number of lines of\/ |\parshape|); or
+one of the dimensions ^|\pagetotal|, ^|\pagegoal|, ^|\pagestretch|,
+^|\pagefilstretch|, ^|\pagefillstretch|, ^|\pagefilllstretch|, ^|\pageshrink|,
+^|\pagedepth|. In horizontal modes you can also refer to a special integer,
+|\the\spacefactor|; in vertical modes there's a special dimension,
+|\the\prevdepth|.
+
+\bugonpage A229, new copy after line 11 (9/23/89)
+
+\ddanger \TeX\ will report the badness of glue setting in a box if
+you ask for the numeric quantity
+^|\badness| after making a box. For example, you might say
+\begintt
+\setbox0=\line{\trialtexta}
+\ifnum\badness>250 \setbox0=\line{\trialtextb}\fi
+\endtt
+The badness is between 0 and 10000
+unless the box is overfull, when |\badness=1000000|.
+
+\bugonpage A271, lines 17--20 (9/23/89)
+
+\ninepoint
+\beginsyntax
+  \alt<countdef token>\alt^|\count|<8-bit number>\alt<codename><8-bit number>
+  \alt<chardef token>\alt<mathchardef token>\alt^|\parshape|\alt^|\inputlineno|
+  \alt^|\hyphenchar|<font>\alt^|\skewchar|<font>\alt^|\badness|
+\endsyntax
+
+\bugonpage A272, lines 3--4 (9/23/89)
+
+\ninepoint\noindent
+value is between 0~and $2^8-1=255$; a ^\<4-bit number> is similar.
+
+\bugonpage A273, insert after lines 11, 20, 21, 21, 38 (9/23/89)
+
+\ninepoint
+\begindisplay
+|\holdinginserts|\quad(positive if insertions remain dormant in output box)\cr
+|\language|\quad(the current set of hyphenation rules)\cr
+|\lefthyphenmin|\quad(smallest fragment at beginning of hyphenated word)\cr
+|\righthyphenmin|\quad(smallest fragment at end of hyphenated word)\cr
+|\errorcontextlines|\quad(maximum extra context shown when errors occur)\cr
+\enddisplay
+
+\bugonpage A274, insert after line 4 (9/23/89)
+
+\ninepoint\indent
+|\emergencystretch|\quad(reduces badnesses on final pass of line-breaking)
+
+\bugonpage A275, line 13 (9/23/89)
+
+\ninepoint\noindent
+That makes a total of 103 parameters of all five kinds.
+
+\bugonpage A283, line 14 (9/23/89)
+
+\ninepoint
+\beginsyntax
+  \alt^|\noboundary|\alt^|\unhbox|\alt^|\unhcopy|\alt^|\valign|\alt^|\vrule|
+\endsyntax
+
+\bugonpage A286, lines 3--12 from the bottom (9/23/89)
+
+\ninepoint
+\textindent{$\bull$}%
+\<letter>, \<otherchar>, \kern-1pt^|\char|\<8-bit number>, \<chardef token>,
+\kern-1pt^|\noboundary|.\enskip
+The most common commands of all are the character commands that tell
+\TeX\ to append a character to the current horizontal
+list, using the current font.
+If two or more commands of this type occur in succession, \TeX\ processes
+them all as a unit, converting to ligatures and/or
+inserting kerns as directed by the font information. \ (Ligatures and
+kerns may be influenced by invisible ``boundary'' characters at the left
+and right, unless |\noboundary| appears.) \ Each character
+command adjusts ^|\spacefactor|, using
+the ^|\sfcode| table as described in Chapter~12.
+In unrestricted horizontal mode, a
+`|\discretionary{}{}{}|' item is appended after a character whose code is
+the ^|\hyphenchar| of its font, or after a ligature formed from a sequence
+that ends with such a character.
+
+\bugonpage A287, insert after line 19 (9/23/89)
+
+\ninepoint
+\textindent{$\bull$}%
+|\setlanguage|\<number>.\enskip See the conclusion of Appendix H.
+
+\bugonpage A289, lines 9--14 from the bottom (9/23/89)
+
+\ninepoint\noindent
+$2^{15}-1$. This is done by replacing the character number by its
+^|\mathcode| value. If the
+|\mathcode| value turns out to be $32768=\null$\hex{8000}, however,
+ the \<character>
+is replaced by an ^{active character} token having the original character
+code (0 to~255); \TeX\ forgets the original \<character> and expands this
+active character according to the rules of Chapter~20.
+
+\bugonpage A290, insert before 13th line from bottom (9/23/89)
+
+\ninepoint
+\textindent{$\bull$}%
+|\noboundary|. This command is redundant and therefore has no
+effect; boundary ligatures are automatically disabled in math modes.
+
+\bugonpage A296, line 16 from the bottom (9/22/89)
+
+\noindent[There should be a `|^|' just above the `|3|' in the line below.
+This was mistakenly dropped by the printer some time during 1985; it was
+correct in the first two printings and it has always been correct inside the
+computer!]
+
+\bugonpage A309, lines 3--5 (9/23/89)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss8.4.\enspace}\ignorespaces
+|$|$_{3}$ |x|$_{11}$ |^|$_7$ |2|$_{12}$ |$|$_{3}$ |~|$_{13}$ \]$_{10}$
+\cstok{TeX} |b|$_{12}$ |v|$_{12}$ \]$_{10}$. The final space comes from the
+\<return> placed at the end of the line. Code |^^6| yields |v| only
+when not followed by |0|--|9| or |a|--|f|.
+The initial space is ignored, because state~$N$
+governs the beginning of the line.
+
+\bugonpage A314, line 27 (9/23/89)
+
+\ninepoint\noindent
+The English word `eighteen' might deserve similar treatment.
+\TeX's hyphenation algorithm will not make such spelling changes automatically.
+
+\bugonpage A318, line 19 (3/3/89)
+
+\ninepoint
+|\def\clearnotenumber{\notenumber=0\relax}|
+
+\bugonpage A330, line 3 (8/25/89)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss20.10.\enspace}\ignorespaces
+|\def\overpaid{{\count0=\balance|
+
+\bugonpage A336, lines 4--8 from the bottom (9/23/89)
+
+\ninepoint\noindent
+badness rating of a
+box is at most 10000, except that the |\badness| of
+an overfull box is 1000000.  |INITEX| initializes |\tolerance| to
+10000, thereby making all line breaks feasible. Penalties of 10000 or more
+prohibit breaks; penalties of $-10000$ or less make breaks mandatory. The
+cost of a page break is 100000, if the badness is 10000 and if the
+associated penalties are less than 10000 in magnitude (see Chapter~15).
+
+\bugonpage A337, lines 2--16 (9/23/89)
+
+\ninepoint\noindent
+ifies characters whose codes differ by~64
+from the codes of |?|, |@|, |A|; this convention applies only to
+characters with ASCII codes less than~128. There are 256 possible characters,
+hence 256 entries in each of the |\catcode|, |\mathcode|,
+|\lccode|, |\uccode|, |\sfcode|, and |\delcode| tables. All
+|\lccode|, |\uccode|, and |\char| values
+must be less than~256. A font has at most 256 characters. There are
+256~|\box| registers, 256~|\count| registers, 256~|\dimen| registers,
+256~|\skip| registers, 256~|\muskip| registers, 256~|\toks| registers,
+256~hyphenation tables.
+The ``at size'' of a font must be less than~$2048\pt$, i.e.,~$2^{11}\pt$.
+Math delimiters are encoded by multiplying the math~code of the ``small
+character'' by~$2^{12}$. The magnitude of
+a~\<dimen> value must be less than~$16384\pt$, i.e.,~$2^{14}\pt$;
+similarly, the \<factor> in a~\<fil dimen> must be less than~$2^{14}$.
+A~|\mathchar| or |\spacefactor| or |\sfcode| value must be less than~$2^{15}$;
+a~|\mathcode| or |\mag| value must be less than or equal to~$2^{15}$,
+and $2^{15}$ denotes an ``active'' math character. There
+are $2^{16}\rm\,sp$ per~pt. A~|\delcode| value
+must be less than~$2^{24}$; a~|\delimiter|, less than $2^{27}$.
+The |\end| command sometimes contributes
+a penalty of $-2^{30}$ to the current page. A~\<dimen> must be less than
+$2^{30}\rm\,sp$ in absolute value; a~\<number> must be
+less than $2^{31}$ in absolute value.
+
+\bugonpage A348, line 12 from the bottom (9/23/89)
+
+\ninepoint\noindent
+^|\showboxbreadth||=5 |^|\showboxdepth||=3 |^|\errorcontextlines||=5|
+
+\bugonpage A364, insert before line 18 from the bottom (9/23/89)
+
+\ninepoint\noindent
+^|\lefthyphenmin||=2 |^|\righthyphenmin||=3 % disallow x- or -xx breaks|
+
+\bugonpage A364, line 5 from the bottom (9/23/89)
+
+\ninepoint\noindent
+|\def|^|\fmtname||{plain}\def\fmtversion{3.0} % identifies the current format|
+
+\bugonpage A369, insert before line 5 from the bottom (9/23/89)
+
+\ninepoint
+Modern keyboards allow 256 codes to be input, not just 128; so \TeX\
+represents characters internally as numbers in the range 0--255 (i.e.,
+\oct{000}--\oct{377}, or \hex{00}--\hex{FF}). Implementations of \TeX\
+differ in which characters they will accept in input files and which
+they will transmit to output files; these subsets can be specified
+independently. A completely permissive version of \TeX\ allows full
+256-character input and output; other versions might ignore all
+but the visible characters of ASCII; still other versions might
+distinguish the tab character (code \oct{011}) from a space on input,
+but might output each tab as a sequence of three characters |^^I|.
+
+\bugonpage A370, lines 3--7 (9/23/89)
+
+\ninepoint\noindent
+close as possible to the ASCII conventions.
+\ (b)~Make sure that codes \oct{041}--\oct{046}, \oct{060}--\oct{071},
+\oct{141}--\oct{146}, and \oct{160}--\oct{171} are present and that
+each unrepresentable
+internal code $<\null$\oct{200} leads to a representable code when \oct{100} is
+added or subtracted; then all 256 codes can be input and output.
+\ (c)~Cooperate with everyone else who shares
+the same constraints, so that you all adopt the same policy.
+\ (See Appendix~J for information about the \TeX\ Users Group.)
+
+\bugonpage A370, bottom line (9/23/89)
+
+\ninepoint\noindent
+doesn't matter if these symbols have their plain
+\TeX\ meanings or not. \ (6)~There is a special convention for
+representing characters 0--255 in the hexadecimal forms
+|^^00|--|^^ff|, explained in Chapter~8. This convention is always
+acceptable as input, when |^| is any character of catcode~7. Text
+output is produced with this convention only when representing
+characters of code $\ge128$ that a \TeX\ installer has chosen not to
+output directly.
+
+\bugonpage A385, line 8 (5/14/89)
+
+\ninepoint
+|\def\beginbox{\setbox0=\hbox\bgroup}|
+
+\bugonpage A400, line 18 from the bottom (9/23/89)
+
+\ninepoint\noindent
+page prematurely if you want to pass a signal. \ (Set
+^|\holdinginserts| positive to pass a signal when the contents of\/
+|\box255| will be sent back through the page builder again, if any
+insertions are present.)
+
+\bugonpage A419, lines 4--6 (9/23/89)
+
+\ninepoint\noindent
+shortened or lengthened anyway;
+book preparation with \TeX, as with type, encourages interaction between
+humans and machines.) \
+The lines of the quotations are set ^{flush right} by using
+^|\obeylines| together with a stretchable ^|\leftskip|:
+
+\bugonpage A444, lines 21--26 (9/23/89)
+
+\ninepoint\noindent
+following one, using the specified family and the current size, then
+insert the ligature character and continue as specified by the font;
+two characters may collapse into one, or a new character may appear.
+Otherwise if the font information
+shows a kern between the current symbol and the next, insert a kern item
+after the current Ord atom and move to the next item after that.
+Otherwise (i.e., if no ligature or kern is specified between the present
+text symbol and the following character), go to Rule~17.
+
+\bugonpage A453, lines 12--14 from the bottom (9/23/89)
+
+\begingroup
+\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
+\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
+\ninepoint\noindent
+Exception: The character
+`|.|'~is treated as if it were a \<letter> of code~0
+when it appears in a pattern. Code~0 (which obviously cannot match a nonzero
+|\lccode|) is used by \TeX\ to represent the
+left or right edge of a word when it is being hyphenated.
+
+\endgroup
+
+\bugonpage A454, lines 7--15 from the bottom (9/23/89)
+
+\begingroup
+\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
+\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
+\ddanger If a trial word $l_1\ldots l_n$ has been found by this process,
+hyphenation will still be abandoned unless $n\ge\lambda+\rho$, where
+$\lambda=\max(1,\hbox{|\lefthyphenmin|})$ and
+$\rho=\max(1,\hbox{|\righthyphenmin|})$.
+\ (Plain \TeX\ takes $\lambda=2$ and $\rho=3$.) \ Furthermore, the items
+immediately following the trial word must consist of zero or more
+characters, ligatures, and implicit kerns, followed immediately by
+either glue or an explicit kern or a penalty item or a whatsit or an
+item of vertical mode material from ^|\mark|, ^|\insert|, or ^|\vadjust|.
+Thus, a box or rule or math formula or discretionary following too closely
+upon the trial word will inhibit hyphenation. (Since \TeX\ inserts
+empty discretionaries after ^{explicit hyphens}, these rules imply that
+already-hyphenated compound words will not be further hyphenated by
+the algorithm.)
+
+\endgroup
+
+\bugonpage A455, new copy after line 13 (9/23/89)
+
+\begingroup
+\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
+\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
+\ddanger \looseness=-1
+So far we have assumed that \TeX\ knows only one style of
+hyphenation at a time; but in fact \TeX\ can remember up to 256
+distinct sets of rules, if you have enough memory in your computer. An
+integer parameter called ^|\language| selects the rules actually used;
+every ^|\hyphenation| and ^|\patterns| specification appends new rules
+to those previously given for the current value of\/ |\language|.
+\ (If\/ |\language| is negative or greater than 255, \TeX\ acts as if
+|\language|$\null=0$.) \ All |\patterns| for all languages must be
+given before a paragraph is typeset, if |INITEX| is used for
+typesetting.
+
+\ddanger \TeX\ is able to work with several languages in the same
+paragraph, because it operates as follows. At the beginning of a
+paragraph the ``current language'' is defined to be~0. Whenever a
+character is added to the current paragraph (i.e., in unrestricted
+horizontal mode), the current language is compared to |\language|; if
+they differ, the current language is reset and a whatsit node
+specifying the new current language is inserted before the character.
+Thus, if you say `|\def\french{\language1...}|' and `|mix| |{\french
+franc/ais}| |with| |English|', \TeX\ will put whatsits before the |f|
+and the~|w|; hence it will use language~1 rules when hyphenating
+|franc/ais|, after which it will revert to language~0. You can insert
+the whatsit yourself (even in restricted horizontal mode) by saying
+^|\setlanguage|\<number>; this changes the current language but it
+does not change |\language|.
+
+\endgroup
+
+\bugonpage A459, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\badness|, 214, {\it229}, 271.
+
+\bugonpage A461, right column (9/23/89)
+
+\eightpoint
+caron, {\sl see\/} h\'a\v cek.
+
+\bugonpage A464, line 10 (5/15/89)
+
+\eightpoint
+displays, 87, 103, {\it139--145}, {\it166--167},
+
+\bugonpage A464, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\emergencystretch|, $\underline{107}$, 274.
+
+\bugonpage A465, left column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\errorcontextlines|, $\underline{34}$, 273, {\it348}.
+
+\bugonpage A466, entry for `fractions' (9/23/89)
+
+\eightpoint[Add page 332 to this entry.]
+
+\bugonpage A466, entry for `French'' (9/23/89)
+
+\eightpoint[Add page 455 to this entry.]
+
+\bugonpage A467, entry for `hexadecimal' (9/23/89)
+
+\eightpoint[Add pages 45, 47--48 to this entry.]
+
+\bugonpage A467, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\holdinginserts|, $\underline{125}$, 273, 400.
+
+\bugonpage A467, bottom line (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\hyphenation|, 277, {\it419}, $\underline{452}$--$\underline{453}$, 455.
+
+\bugonpage A468, right column (9/23/89)
+
+\eightpoint
+infinite badness, 97, 107, 111, 229, 317.
+
+\bugonpage A468, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\inputlineno|, 214, 271.
+
+\bugonpage A469, entry for kerns (9/23/89)
+
+\eightpoint[Add pages 286 and 444 to this entry.]
+
+\bugonpage A469, left column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\language| (hyphenation method), 273, $\underline{455}$.
+
+\bugonpage A469, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\lefthyphenmin|, 273, {\it364}, $\underline{454}$.
+
+\bugonpage A470, entry for ligatures (9/23/89)
+
+\eightpoint[Add pages 286 and 444 to this entry.]
+
+\bugonpage A472, left column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\noboundary|, 283, $\underline{286}$, 290.
+
+\bugonpage A473, right column (9/23/89)
+
+\eightpoint
+overfull boxes, 27--30, 94, 229, 238,\par
+\indent\qquad 302--303, 307, 400.\par
+\indent\quad avoiding, 107.
+
+\bugonpage A474, left column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\patterns|, 277, $\underline{453}$, 455.
+
+\bugonpage A476, left column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\righthyphenmin|, 273, {\it364}, $\underline{454}$.
+
+\bugonpage A476, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\setlanguage|, 287, $\underline{455}$.
+
+\bugonpage A476, right column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\showboxbreadth|, 273, $\underline{302}$, 303, {\it348}.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\showboxdepth|, 79, 273, $\underline{302}$, 303, {\it348}.
+
+\bugonpage A479, left column (9/23/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tolerance|, {\it29--30}, 91, 94, $\underline{96}$, 107, 272,\par
+\indent\qquad{\it317}, {\it333}, {\it342}, {\it348}, {\it364}, {\it451}.
+
+\bugonpage A481, right column, last six entries (9/23/89)
+
+\def\frac#1/#2{\leavevmode\kern.1em
+  \raise.5ex\hbox{\the\scriptfont0 #1}\kern-.1em
+  /\kern-.15em\lower.25ex\hbox{\the\scriptfont0 #2}}%
+\eightpoint
+\frac1/2, 67, 332.\par
+1/2, in unslashed form, 141, 186.\par
+\<4-bit number>, $\underline{271}$.\par
+\<8-bit number>, $\underline{271}$, 276--278.\par
+\<15-bit number>, $\underline{271}$, 277, 289, 291.\par
+\<27-bit number>, $\underline{271}$, 289, 291.\par
+
+\bugonpage A483, lines 15 and 21 (9/23/89)
+
+\noindent[Delete these two lines, as TUG's address is no longer c/o AMS.]
+
+% volume B
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Bvii, top two lines (4/21/89)
+
+{\hsize=29pc
+\tenpoint\noindent
+{\it {\sltt WEB} documentation for four utility programs that are
+often used in conjunction with \TeX: {\sltt POOLtype}, {\sltt TFtoPL},
+{\sltt PLtoTF}, and {\sltt DVItype}.}
+\par}
+
+\bugonpage B2, line 32 (6/20/89)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]2.991\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B118, lines 2--4 (3/2/89)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin if\/} $\\{cur\_level}>\\{level\_one}$ {\bf then}\par
+\noindent\hskip20pt{\bf  begin} \\{check\_full\_save\_stack}; \
+ $\\{save\_type}(\\{save\_ptr})\gets\\{insert\_token}$;\par
+\noindent\hskip20pt$\\{save\_level}(\\{save\_ptr})\gets\\{level\_zero}$; \
+ $\\{save\_index}(\\{save\_ptr})\gets t$; \ \\{incr}(\\{save\_ptr});\par
+\noindent\hskip20pt{\bf  end};
+
+\bugonpage B182, line 13 becomes two lines (6/20/89)
+
+\ninepoint\noindent
+$k,\\{kk}$: \\{small\_number};\quad
+ $\{\,$number of digits in a decimal fraction$\,\}$\par\noindent
+$p,q$: \\{pointer};\quad
+ $\{\,$top of decimal digit stack$\,\}$
+
+\bugonpage B182, line 15 from the bottom (6/20/89)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} $k\gets0$; $p\gets\\{null}$; \\{get\_token};\quad
+ $\{\,$\\{point\_token} is being re-scanned$\,\}$
+
+\bugonpage B182, line 11 from the bottom (6/20/89)
+
+\ninepoint\noindent\hskip30pt
+{\bf begin} $q\gets\\{get\_avail}$; $\\{link}(q)\gets p$;
+ $\\{info}(q)\gets\\{cur\_tok}-\\{zero\_token}$;
+ $p\gets q$; $\\{incr}(k)$;
+
+\bugonpage B182, line 8 from the bottom (6/20/89)
+
+\ninepoint\noindent
+\\{done1}: {\bf for} $\\{kk}\gets k$ {\bf downto} 1 {\bf do}\par
+\noindent\hskip20pt
+{\bf begin} $\\{dig}[kk-1]\gets\\{info}(p)$; $q\gets p$; $p\gets\\{link}(p)$;
+ $\\{free\_avail}(q)$;\par
+\noindent\hskip20pt{\bf end};\par
+\noindent\hskip10pt$f\gets\\{round\_decimals}(k)$;
+
+\bugonpage B332, lines 11 and 12 from the bottom (4/8/89)
+
+\ninepoint
+\noindent\hskip10pt
+{\bf begin if\/} $\\{cur\_align}=\\{null}$ {\bf then}
+ \\{confusion}({\tt\char'23endv\char'23});\par\noindent\hskip10pt
+$q\gets\\{link}(\\{cur\_align})$; \ {\bf if\/} $q=\\{null}$ {\bf then}
+ \\{confusion}({\tt\char'23endv\char'23});
+
+\bugonpage B466, line 5 becomes three lines (6/7/89)
+
+\ninepoint
+\noindent
+$\\{mmode}+\\{halign}$: {\bf if\/} \\{privileged} {\bf then}\par\noindent
+\hskip20pt{\bf if\/} $\\{cur\_group}=\\{math\_shift\_group}$
+ {\bf then} \\{init\_align}\par\noindent\hskip20pt
+{\bf else} \\{off\_save};
+
+\bugonpage B518, line 25 (8/31/89)
+
+\ninepoint\noindent\hskip10pt
+$\\{undump}(\\{lo\_mem\_stat\_max}+1)(\\{lo\_mem\_max})(\\{rover})$; \
+$p\gets\\{mem\_bot}$; \ $q\gets\\{rover}$;
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\buginvol C, in general (9/23/89)
+
+\ninepoint\noindent
+[Change `127' to `255' and `128' to `256' in contexts referring to character
+codes. This happens on pages 188(thrice) and 251.]
+
+\bugonpage C91, lines 12 and 13 (8/31/89)
+
+\begintt
+\mode=cheapo; input newface
+\endtt
+and the same file should also produce a high-resolution font if we start with
+
+\bugonpage C204, line 4 (8/18/89)
+
+\ninepoint\noindent
+so that
+\\{currenttransform} multiplies all $y$~coordinates by
+\\{aspect\_ratio}, when paths are\cutpar
+
+\bugonpage C212, lines 24--27 (9/30/89)
+
+\ninepoint
+\begindisplay
+{\it boundarychar}\quad&the right boundary character for ligatures and kerns\cr
+\enddisplay
+All of these quantities are numeric. They are initially zero at the
+start of a job, except for {\it year\/}, {\it month\/},
+ {\it day\/}, and {\it time\/}, which
+are initialized to the time the run began; furthermore, {\it boundarychar\/} is
+initially~$-1$. A {\it granularity\/} of zero is equivalent to
+ $\hbox{\it granularity\/}=1$.
+A preloaded base file like plain \MF\ will usually give nonzero values to
+several other internal quantities on this list.
+
+\bugonpage C259, lines 16 and 17 from the bottom (5/14/89)
+
+\tenpoint
+\noindent
+|screenchars|; \ |screenstrokes|; \ |imagerules|; \ |gfcorners|; \
+|nodisplays|;\hfil\break
+|notransforms|; \ |input| \<filename>.
+
+\bugonpage C282, the three lines following the chart (9/30/89)
+
+\tenpoint\noindent
+\MF\ can also be configured to accept any or all of the character codes
+128--255.
+However, \MF\ programs that make use of anything in addition to the 95
+standard ASCII characters cannot be expected to run on other systems, so
+the use of extended character sets is discouraged.
+
+\bugonpage C316, bottom 14 lines and top 30 of page C317 (9/30/89)
+
+\ninepoint
+Ligature information and kerning information is specified in short
+``^{ligtable programs}'' of a particularly simple form. Here's an example
+that illustrates most of the features (although it is not a serious
+example of typographic practice):
+\beginlines
+^|ligtable|| "f": "f" =: oct"013", "i" |\||=: oct"020", skipto 1;|
+|ligtable "o": "b": "p": "e" kern .5u#, "o" kern .5u#, "x" kern-.5u#,|
+|          1:: "!" kern u#;|
+\endlines
+This sequence of instructions can be paraphrased as follows:
+\smallskip
+\hangindent 3pc
+Dear \TeX, when you're typesetting an~`f' with this font, and when the
+following character also belongs to this font, look at it closely because
+you might need to do something special: If that following character is
+another~`f', replace the two f's by character code |oct"013"|
+[namely `\char'13'\kern.5pt];
+if it's an `i', retain the `f' but replace the `i' by character code
+|oct"020"| [a dotless `\char'20'\kern.5pt];
+otherwise skip down to label `|1::|' for further instructions.
+When you're typesetting an `o' or~`b' or~`p', if the next input to \TeX\ is
+`e' or~`o', add a half unit
+of space between the letters; if it's an `x', subtract a half unit; if it's an
+exclamation point, add a full unit. The last instruction applies also
+to exclamation points following~`f' (because of the label `|1::|').
+\smallskip\noindent
+When a character code appears in front of a colon, the colon ``labels''
+the starting place for that character's ligature and kerning program,
+which continues to the end of the ligtable statement. A double colon denotes
+a ``local label''; a |skipto| instruction advances to the next matching local
+label, which must appear before 128 ligtable steps intervene. The special
+label \|\||:| can be used to initiate ligtable instructions for an invisible
+``left boundary character'' that is implicitly present just before every
+word; an invisible ``right boundary character'' equal to {\it boundarychar\/} is
+also implicitly present just after every word, if {\it boundarychar\/}
+ lies between
+0 and~255.
+
+The general syntax for ligtable programs is pretty easy to guess from
+these examples, but we ought to exhibit it for completeness:
+\beginsyntax \chardef\\=`\|
+<ligtable command>\is[ligtable]<ligtable program><optional skip>
+<ligtable program>\is<ligtable step>\alt<ligtable program>[,]<ligtable step>
+<optional skip>\is[,] [skipto]<code>\alt<empty>
+<ligtable step>\is<code><ligature op><code>
+ \alt<code>[kern]<numeric expression>
+ \alt<label><ligtable step>
+<ligature op>\is[=:]\alt[\\=:]\alt[\\=:>]\alt[=:\\]\alt[=:\\>]%
+  \alt[\\=:\\]\alt[\\=:\\>]\alt[\\=:\\>>]
+<label>\is<code>[:]\alt<code>[::]\alt[\\\\:]
+<code>\is<numeric expression>\alt<string expression>
+\endsyntax
+A \<code> should have a numeric value between 0 and 255, inclusive,
+after having been rounded to the nearest integer; or it should be a
+string of length~1, in which case it denotes the corresponding
+^{ASCII} code (Appendix~C\null). For example, |"A"| and |64.61| both
+specify the code value 65. Vertical bars to the left or right of `|=:|'
+tell \TeX\ to retain the original left and/or right character that invoked a
+ligature. Additional `|>|' signs tell \TeX\ to advance its focus of attention
+instead of doing any further ligtable operations at the current
+character position.
+
+\bugonpage C338, lines 21 and 22 (9/30/89)
+
+\ninepoint\noindent
+and 127--255 have to be specified with the `|#|' option,
+on non-fancy installations of \TeX,
+and so does code 35 (which is the ASCII code of `|#|' itself).
+
+\bugonpage C346, left column, after line 14 (9/30/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+\||=:|, {\it316}, $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+\||=:>|, $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|=:|\|, $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|=:|\||>|, $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+\||=:|\|, $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+\||=:|\||>|, $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+\||=:|\||>>|, $\underline{317}$.\par
+
+\bugonpage C346, left column, after line 31 (9/30/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|::| (local label), $\underline{317}$.\par
+\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+\|\||:| (left boundary label), $\underline{317}$.\par
+
+\bugonpage C347, left column (9/30/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|boundarychar|, 212, 317.
+
+\bugonpage C352, left column (9/30/89)
+
+\eightpoint[Change `\<ligature replacement>' to `\<ligature op>'.]
+
+\bugonpage C354, left column (9/30/89)
+
+\eightpoint
+\<optional skip>, 217.
+
+\bugonpage C356, left column (9/30/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|skipto|, {\it316}, $\underline{317}$.
+
+% Volume D
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Dvi, bottom two lines, and top lines of page vii (4/21/89)
+
+{\hsize=29pc \tenpoint
+\textindent\bull ``\MF\/ware'' by Donald~E. Knuth, Tomas~G. Rokicki, and
+Ar\-thur~L. Samuel, Stanford Computer Science Report 1255 (Stanford,
+California, April 1989), 207~pp. \ {\it The {\sltt WEB} programs for
+four utility programs that are often used in conjunction with
+\slMF\kern1pt: {\sltt GFtype}, {\sltt GFtoPK}, {\sltt GFtoDVI},
+and {\sltt MFT}.}
+\par}
+
+\bugonpage D63, line 9 (8/31/89)
+
+\tenpoint\noindent
+\\{mem}, so we
+allow pointers to assume any \\{halfword} value. The minimum memory
+index represents\cutpar
+
+\bugonpage D63, line 28 (8/31/89)
+
+\tenpoint\centerline{$\\{null}=\\{mem\_min}<\\{lo\_mem\_max}<
+\\{hi\_mem\_min}<\\{mem\_top}\le\\{mem\_end}\le\\{mem\_max}$.}
+
+\bugonpage D67, in the July 1987 printing (4/7/89)
+
+\ninepoint\noindent
+[Delete line 7, which has a redundant `{\bf if\/} $r=p$ {\bf then}';
+  move line 8 to the left 10 points for alignment; and restore the following
+  line (which was deleted by mistake after line 8):
+  
+  \noindent\hskip10pt
+  $\\{node\_size}(p)\gets q-p$\quad$\{\,$reset the size in case it grew$\,\}$
+  
+  \noindent
+  These corrections are needed only in the reprinting made July, 1987.]
+
+\bugonpage D228, in the July 1987 printing (4/7/89)
+
+\ninepoint\noindent
+[Delete lines 14--15, which were inserted erroneously from a previous errata
+list; and restore the following lines (which were deleted by mistake):
+
+\noindent\hskip20pt
+{\bf begin} \\{double}(\\{max\_coef}); \
+\\{double}(\\{x0}); \
+\\{double}(\\{x1}); \
+\\{double}(\\{x2});\par\noindent\hskip20pt
+\\{double}(\\{y0}); \
+\\{double}(\\{y1}); \
+\\{double}(\\{y2});\par\noindent\hskip20pt
+{\bf end}
+
+\noindent
+These corrections are needed only in the reprinting made July, 1987.]
+
+\bugonpage D248, in the July 1987 printing (4/7/89)
+
+\ninepoint\noindent
+[Delete line 16, which begins with `$d\gets\\{take\_fraction}$';
+and restore the following line (which was deleted by mistake after line 22):
+
+\noindent\hskip10pt
+{\bf if\/} $d<\\{alpha}$ {\bf then} $d\gets\\{alpha}$
+
+\noindent
+These corrections are needed only in the reprinting made July, 1987.]
+
+\bugonpage D389, line 10 (6/20/89)
+
+\ninepoint\noindent\hskip20pt
+\\{help1}({\tt\char'23
+The\]expression\]above\]should\]have\]been\]a\]number\]>=3/4.\char'23});
+
+\bugonpage D504, line 25 (8/31/89)
+
+\ninepoint\noindent\hskip10pt
+$\\{undump}(\\{lo\_mem\_stat\_max}+1)(\\{lo\_mem\_max})(\\{rover})$; \
+$p\gets\\{mem\_min}$; \ $q\gets\\{rover}$;
+
+\bugonpage D510, in the July 1987 printing (4/7/89)
+
+\ninepoint\noindent
+[Move the 7th-to-last line, which begins with `\\{internal}[\\{fontmaking}]',
+one line down, and indent it to the right by 10 more points.
+This correction is needed only in the reprinting made July, 1987.]
+
+% volume E
+\hsize=29pc
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+\bugonpage Exiii, bottom four lines (5/5/89)
+
+{\hsize=29pc \tenpoint
+\textindent\bull ``Metamarks: Preliminary studies for a Pandora's Box of
+shapes'' by Neenie Billawala,
+Stanford Computer Science Report 1256 (Stanford,
+California, May 1989), 132~pp. \ {\it Lavishly illustrated studies in
+parameter variation, leading to the design of a new family of
+typefaces called Pandora.}
+\par}
+
+\bugonpage E401, bottom line (5/16/89)
+
+\ninepoint\noindent
+{\bf \def\_{\kern.04em\vbox{\hrule width.3em height .6pt}\kern.08em}%
+math\_fit}$(-.3\\{cap\_height}\0*\\{slant}-.5u\0,\\{ic}\0)$;\par\noindent
+{\bf penlabels}$(1,2,3,4,5,6,7,8)$; {\bf endchar\/};
+\smallskip\noindent
+[some points and labels are missing at the tip of the tail on page 400]
+\bye
+Now here are some that I will make soon!
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.four b/Master/texmf-dist/doc/generic/knuth-errata/errata.four
new file mode 100644
index 00000000000..11d0435e749
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.four
@@ -0,0 +1,1052 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 1987--1988}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting}, Volumes A--E\null, between
+16 June 1987 and 20 February 1989. Corrections made to
+the softcover version of {\sl The \TeX book} are the same as corrections to
+Volume~A\null. Corrections to the softcover version of {\sl The
+\slMF\kern1ptbook\/} are the same as corrections to Volume~C\null.
+Some of these corrections have already been made in reprintings
+of the books. Some of these corrections affect the indexes and
+mini-indexes of Volumes B~and~D in ways not shown here. Corrections
+made up to 15 June 1987 appear in other files.
+% volume A
+
+\bugonpage A159, line 22 (2/15/88)
+
+\ninepoint\noindent
+`|\nolimits|' if the normal |\displaylimits|
+convention has been overridden; a Rad\cutpar
+
+\bugonpage A213, lines 34--35 (12/23/87)
+
+\ninepoint\noindent
+text will be a single control sequence token, defined to be like |\relax| if
+its meaning is currently undefined.
+
+\bugonpage A299, line 30 (7/6/88)
+
+\ninepoint\indent\tt
+Fatal format file error; I'm stymied.
+
+\bugonpage A326, line 12 (12/12/87)
+
+\ninepoint\noindent
+its natural width. The |\hbox| version also invokes |\everymath|.
+
+\bugonpage A359, line 2 (11/6/88)
+
+\ninepoint\noindent
+|\mathchardef\ldotp="613A\mathchardef\cdotp="6201\mathchardef\colon="603A|
+
+\bugonpage A359, lines 35--38 (5/24/88)
+
+\ninepoint\noindent
+|\def\updownarrow{\delimiter"326C33F } \def\arrowvert{\delimiter"033C000 }|%
+ \par\noindent
+|\def\Updownarrow{\delimiter"326D377 } \def\Arrowvert{\delimiter"033D000 }  |%
+ \par\noindent
+|\def\vert{\delimiter"026A30C }        \def\Vert{\delimiter"026B30D }     |%
+ \par\noindent
+|\def\backslash{\delimiter"026E30F }   \def\bracevert{\delimiter"033E000 }|
+
+\bugonpage A364, line 35 (11/6/88)
+
+\ninepoint\noindent
+|\def\fmtname{plain}\def\fmtversion{2.94} % identifies the current format|
+
+\bugonpage A379, line 15 (10/12/87)
+
+\ninepoint
+|\def\deleterightmost#1{\edef#1{\expandafter\xyzzy#1\xyzzy}}|
+
+\bugonpage A383, lines 7--15 from the bottom (1/4/89)
+
+\begintt
+ 209 strings out of 1685
+ 1659 string characters out of 17636
+ 27618 words of memory out of 52821
+ 1172 multiletter control sequences out of 2500
+\endtt
+Consequently there was plenty of room for more macros: $52821-27618=
+25203$ unused cells of main memory, $2500-1172=1328$ of name memory,
+$1685-209=1476$ of string memory, and $17636-1659=15977$ of character memory.
+But a fairly large \TeX\ was being used, and only the macros of
+Appendices B and~E were loaded; in other circumstances it might have
+been necessary to conserve space.
+
+\bugonpage A454, lines 23--29 (8/13/87)
+
+\begingroup
+\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
+\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
+\ddanger If a suitable starting letter is found, let it be in font~$f$.
+Hyphenation is abandoned unless the |\hyphenchar| of~$f$ is between
+0 and~255, and unless a character of that number exists in the font.
+If this test is passed, \TeX\ continues to scan forward
+until coming to something that's not one of the following three
+``admissible items'': (1)~a character in font~$f$ whose |\lccode|
+is nonzero; (2)~a ligature formed entirely from characters of type~(1);
+(3)~an implicit kern. The first inadmissible item terminates this part of
+the process; the trial word consists of all the letters found in admissible
+items. Notice that all of these letters are in font~$f$.
+
+\endgroup % end the special hyphenation conventions
+
+\bugonpage A458, left column, line 19 (2/15/88)
+
+\eightpoint\indent
+|\|\| ( $\Vert$ ), {\it146--147}, {\it171}, $\underline{361}$, 435, 438.
+
+\bugonpage A462, left column, line 7 (10/9/87)
+
+\eightpoint\indent\qquad 152, 178, $\underline{360}$.
+
+\bugonpage A463, left column (4/17/88)
+
+\eightpoint\indent
+\hbox to0pt{\hss\lower1pt\hbox{*}}|\day|, 273, 349, {\it406}.
+
+\bugonpage A464, left column, under Displays (12/8/88)
+
+\eightpoint\indent\quad
+non-centered, 186, 326, 375--376, 420--421.
+
+\bugonpage A465, entry for {\tt\char`\\everymath} (12/12/87)
+
+\eightpoint\indent[Include also a reference to page 326.]
+
+\bugonpage A465, right column (7/6/88)
+
+\eightpoint\indent{\tt Fatal format file error}, 299.
+
+\bugonpage A473, entry for `page builder' (8/13/87)
+
+\eightpoint\indent\quad when exercised, 122, 280--283, 286--287.
+
+\bugonpage A474, left column (12/27/88)
+
+\eightpoint\indent
+\hbox to0pt{\hss\lower1pt\hbox{*}}|\parshape|, 101--102, 214, 271, 277, 283,
+
+\bugonpage A480, right column (2/15/88)
+
+\eightpoint\indent|\vdots| ( $\vdots$ ), {\it177}, $\underline{359}$.
+
+\bugonpage A481, right column (7/3/87)
+
+\eightpoint|\z@|, $\underline{347}$, 348.\par
+|\z@skip|, $\underline{347}$, 348.
+% volume B
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage B2, line 32 (2/20/89)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]2.97\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B38, lines 7--9 from the bottom (11/6/88)
+
+\tenpoint\noindent[Delete this paragraph; it is being moved to page B214.]
+
+\bugonpage B38, line 5 from the bottom (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin if\/} \\{log\_opened} {\bf then} $\\{selector}\gets\\{term\_and\_log}$
+
+\bugonpage B39, line 5 (12/14/88)
+
+\ninepoint\noindent\kern50pt
+{\bf if\/} \\{log\_opened} {\bf then} \\{error};
+
+\bugonpage B52, line 5 (8/13/87)
+
+\tenpoint\noindent
+cannot be done, i.e., if $\\{hi\_mem\_min}=\\{lo\_mem\_max}+1$,
+we have to quit.
+
+\bugonpage B54, lines 34--35 (7/9/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin if\/} $\\{hi\_mem\_min}-\\{lo\_mem\_max}\ge1998$
+ {\bf then} $t\gets\\{lo\_mem\_max}+1000$\par\noindent\kern10pt
+{\bf else} $t\gets\\{lo\_mem\_max}+1+(\\{hi\_mem\_min}-\\{lo\_mem\_max})
+\,\mathbin{\bf div}\,2$;\quad\kern-4pt
+$\{\,\\{lo\_mem\_max}+2\le t<\\{hi\_mem\_min}\,\}$
+
+\bugonpage B108, new line after line 8 (5/24/88)
+
+\ninepoint\noindent\kern20pt
+$d$: \\{integer};\quad
+$\{\,$number of characters in incomplete current string$\,\}$
+
+\bugonpage B108, lines 31--33 (5/24/88)
+
+\ninepoint\noindent\kern10pt
+$\\{str\_room}(l)$; $d\gets\\{cur\_length}$;\par\noindent\kern10pt
+{\bf while} $\\{pool\_ptr}>\\{str\_start}[\\{str\_ptr}]$ {\bf do}
+ \par\noindent\kern20pt
+{\bf begin} \\{decr}(\\{pool\_ptr});
+ $\\{str\_pool}[\\{pool\_ptr}+l]\gets\\{str\_pool}[\\{pool\_ptr}]$;
+ \par\noindent\kern20pt
+{\bf end};\quad$\{\,$move current string up to make room for another$\,\}$
+\par\noindent\kern10pt
+{\bf for} $k\gets j$ {\bf to} $j+l-1$ {\bf do} $\\{append\_char}(\\{buffer}[k])$;
+\par\noindent\kern10pt
+$\\{text}(p)\gets\\{make\_string}$; $\\{pool\_ptr}\gets\\{pool\_ptr}+d$;
+
+\bugonpage B115, line 12 (4/28/88)
+
+\ninepoint\noindent\hskip10pt
+$\\{group\_code}=0\to\\{max\_group\_code}$;\quad
+ $\{\,$\\{save\_level} for a level boundary$\,\}$
+
+\bugonpage B141, line 19 (4/28/88)
+
+\ninepoint\noindent
+\\{par\_token}: \\{halfword};\quad
+ $\{\,$token representing `|\par|'$\,\}$
+
+\bugonpage B150, line 24 (4/28/88)
+
+\tenpoint\noindent{\bf 358.\quad}%
+The present point in the program is reached only when the \\{expand}
+routine has inserted\cutpar
+
+\bugonpage B151, mini-index (4/28/88)
+
+\eightpoint\noindent
+Delete the entry for `\\{no\_expand}'; replace it by:
+
+\indent\\{expand}: {\bf procedure}, \S366.
+
+\bugonpage B154, lines 25, 29, 34 respectively (9/20/87)
+
+\ninepoint\noindent\hskip20pt
+$\\{cvl\_backup},\\{radix\_backup},\\{co\_backup}$: \\{small\_number};\quad
+ $\{\,$to save \\{cur\_val\_level}, etc.$\,\}$\par\noindent\hskip10pt
+$\\{co\_backup}\gets\\{cur\_order}$;
+ $\\{backup\_backup}\gets\\{link}(\\{backup\_head})$;\par\noindent\hskip10pt
+$\\{cur\_order}\gets\\{co\_backup}$;
+ $\\{link}(\\{backup\_head})\gets\\{backup\_backup}$;
+
+\bugonpage B155, new entry for mini-index (9/20/87)
+
+\eightpoint\indent
+\\{cur\_order}: \\{glue\_ord}, \S447.
+
+\bugonpage B156, line 28 (12/23/87)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin }$\\{eq\_define}(\\{cur\_cs},\\{relax},256)$;
+
+\bugonpage B157, mini-index (12/23/87)
+
+\eightpoint\noindent
+Delete the entries for `\\{eqtb}' and `\\{frozen\_relax}'; replace them
+by the following:
+
+\indent\\{eq\_define}: {\bf procedure}, \S227.\par
+$\\{relax}=0$, \S207.\par
+
+\bugonpage B162, lines 12--14 (4/30/88)
+
+\ninepoint\noindent\hskip10pt
+{\bf repeat} $\\{link}(\\{temp\_head})\gets\\{null}$;\par\noindent\hskip20pt
+{\bf if\/} $(\\{info}(r)>\\{match\_token}+127)\lor
+ (\\{info}(r)<\\{match\_token})$ {\bf then}
+ $s\gets\\{null}$\par\noindent\hskip20pt
+{\bf else begin} $\\{match\_chr}\gets\\{info}(r)-\\{match\_token}$; \
+ $s\gets\\{link}(r)$; \ $r\gets s$; \ $p\gets\\{temp\_head}$; \
+ $m\gets 0$;
+
+\bugonpage B177, bottom line before mini-index (7/13/88)
+
+\ninepoint\noindent\hskip10pt
+$\\{cur\_val}\gets0$; \ 
+ $\\{cur\_val\_level}\gets\\{int\_val}$; \
+ $\\{radix}\gets0$; \
+ $\\{cur\_order}\gets0$;
+
+\bugonpage B181, line 31 (4/28/88)
+
+\ninepoint\noindent
+[Change `$x$ units per sp' to `$x$ sp per unit'! This change also
+should be made on line~1 of page B183 and line $-8$ of page B590.]
+
+\bugonpage B188, line 8 (5/25/88)
+
+\ninepoint\noindent
+{\bf function} $\\{str\_toks}(b:\\{pool\_pointer})$: \\{pointer};\quad
+ $\{\,$changes the string \\{str\_pool}$[b\to\\{pool\_ptr}]$ to a token list$\,\}$
+
+\bugonpage B188, line 13 (5/25/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin} \\{str\_room}(1); $p\gets\\{temp\_head}$;
+ $\\{link}(p)\gets\\{null}$; $k\gets b$;
+
+\bugonpage B188, line 20 (5/25/88)
+
+\ninepoint\noindent\kern10pt
+$\\{pool\_ptr}\gets b$; $\\{str\_toks}\gets p$;
+
+\bugonpage B188, new line after line 28 (5/25/88)
+
+\ninepoint\noindent\kern20pt
+$b$: \\{pool\_pointer};\quad$\{\,$base of temporary string$\,\}$
+
+\bugonpage B188, line 31 (5/25/88)
+
+\ninepoint\noindent\kern10pt
+{\bf else begin} $\\{old\_setting}\gets\\{selector}$;
+ $\\{selector}\gets\\{new\_string}$; $b\gets\\{pool\_ptr}$;
+
+\bugonpage B188, line 41 (5/25/88)
+
+\ninepoint\noindent\kern20pt
+$\\{selector}\gets\\{old\_setting}$; $\\{the\_toks}\gets\\{str\_toks}(b)$;
+
+\bugonpage B190, lines 16--18 (5/25/88)
+
+\ninepoint\noindent\kern20pt
+$b$: \\{pool\_pointer};\quad$\{\,$base of temporary string$\,\}$\par
+\noindent\kern10pt
+{\bf begin} $c\gets\\{cur\_chr}$;
+ $\langle\,$Scan the argument for command $c${\eightrm\kern.5em471}$\,\rangle$;
+\par\noindent\kern10pt
+$\\{old\_setting}\gets\\{selector}$;
+$\\{selector}\gets\\{new\_string}$; $b\gets\\{pool\_ptr}$;
+$\langle\,$Print the result of command~$c${\eightrm\kern.5em472}$\,\rangle$;
+\par\noindent\kern10pt
+$\\{selector}\gets\\{old\_setting}$;
+$\\{link}(\\{garbage})\gets\\{str\_toks}(b)$;
+$\\{ins\_list}(\\{link}(\\{temp\_head}))$;
+
+\bugonpage B210, line 36 (5/25/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin if} $(\\{pool\_ptr}+\\{name\_length}>\\{pool\_size})
+ \lor(\\{str\_ptr}=\\{max\_strings})\lor(\\{cur\_length}>0)$ {\bf then}
+
+\bugonpage B211, new line of code before the mini-index (12/14/88)
+
+\ninepoint\noindent
+\\{log\_opened}: \\{boolean};\quad$\{\,$has the transcript file been opened?$\,\}$
+
+\bugonpage B212, line 5 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+$\\{job\_name}\gets0$; \ $\\{name\_in\_progress}\gets\\{false}$; \
+$\\{log\_opened}\gets\\{false}$;
+
+\bugonpage B213, line 24 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+$\\{log\_name}\gets\\{a\_make\_name\_string}(\\{log\_file})$; \
+$\\{selector}\gets\\{log\_only}$; \
+$\\{log\_opened}\gets\\{true}$;
+
+\bugonpage B214, lines 2 and 3 (12/14/88)
+
+\tenpoint\noindent
+messages or even to \\{show\_context}.
+The \\{prompt\_file\_name} routine can result in a \\{fatal\_error},
+but the \\{error}
+routine will not be invoked because \\{log\_opened} will be false.
+\par\noindent\hskip10pt
+The normal idea of \\{batch\_mode} is that nothing at all should be written
+on the terminal. However, in the unusual case that
+no log file could be opened, we make an exception and allow
+an explanatory message to be seen.
+
+\bugonpage B214, lines 7--11 reduce to a single line (12/14/88)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} $\\{selector}\gets\\{term\_only}$;
+
+\bugonpage B224, second-last line (4/28/87)
+
+\ninepoint\noindent
+\\{done}: {\bf if} \\{file\_opened} {\bf then} \\{b\_close}(\\{tfm\_file});\par
+\noindent\hskip10pt $\\{read\_font\_info}\gets g$;
+
+\bugonpage B229, lines 6--8 (11/17/87)
+
+\tenpoint\noindent
+than $2^{27}$.
+If $z<2^{23}$, the individual multiplications $b\cdot z$,
+$c\cdot z$, $d\cdot z$ cannot overflow; otherwise we will divide $z$ by 2,
+4, 8, or 16, to obtain a multiplier less than $2^{23}$, and we can
+compensate for this later. If $z$ has thereby been replaced by
+$z^\prime=z/2^e$, let $\beta=2^{4-e}$; we shall compute
+
+\bugonpage B229, lines 11--12 (11/17/87)
+
+\tenpoint\noindent
+if $a=0$, or the same quantity minus $\alpha=2^{4+e}z^\prime$ if $a=255$.
+This calculation must be done exactly, in order to guarantee portability
+of \TeX\ between computers.
+
+\bugonpage B230, lines 2--5 (11/17/87)
+
+\ninepoint
+\noindent\hskip10pt{\bf begin} $\\{alpha}\gets16$;\par
+\noindent\hskip10pt{\bf while} $z\ge\oct{40000000}$ {\bf do}\par
+\noindent\hskip20pt{\bf begin} $z\gets z\ {\bf div}\ 2$; \
+ $\\{alpha}\gets\\{alpha}+\\{alpha}$; \ {\bf end};\par
+\noindent\hskip10pt$\\{beta}\gets256\ {\bf div}\ \\{alpha}$; \
+ $\\{alpha}\gets\\{alpha}\ast z$;\par
+
+\bugonpage B245, new entry for mini-index (8/7/87)
+
+\eightpoint\indent
+\\{cur\_s}: \\{integer}, \S616.
+
+\bugonpage B254, line 29 (8/7/87)
+
+\ninepoint\noindent
+\\{cur\_s}:  \\{integer};\quad
+$\{\,$current depth of output box nesting, initially $-1\,\}$
+
+\bugonpage B254, line 31 (8/7/87)
+
+\ninepoint\noindent
+[Remove the statement `$\\{cur\_s}\gets-1$;' and put it on page B244 at the
+end of line 31.]
+
+\bugonpage B259, line 13 (11/9/87)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin }$\\{rule\_wd}\gets\\{rule\_wd}+10$;\quad
+$\{\,$compensate for floating-point rounding$\,\}$\par\noindent\hskip20pt
+$\\{edge}\gets\\{cur\_h}+\\{rule\_wd}$; $\\{lx}\gets0$;
+$\langle\,$Let \\{cur\_h} be the position of the first box, and set
+
+\bugonpage B259, line 17 (11/9/87)
+
+\ninepoint\noindent\hskip20pt
+$\\{cur\_h}\gets\\{edge}-10$; {\bf goto} \\{next\_p};
+
+\bugonpage B263, line 21 (11/9/87)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin }$\\{rule\_ht}\gets\\{rule\_ht}+10$;\quad
+$\{\,$compensate for floating-point rounding$\,\}$\par\noindent\hskip20pt
+$\\{edge}\gets\\{cur\_v}+\\{rule\_ht}$; $\\{lx}\gets0$;
+$\langle\,$Let \\{cur\_v} be the position of the first box, and set
+
+\bugonpage B263, line 25 (11/9/87)
+
+\ninepoint\noindent\hskip20pt
+$\\{cur\_v}\gets\\{edge}-10$; {\bf goto} \\{next\_p};
+
+\bugonpage B266, line 8 (8/7/87)
+
+\ninepoint\noindent\hskip10pt
+\\{dvi\_out}(\\{eop}); \\{incr}(\\{total\_pages}); $\\{cur\_s}\gets-1$;
+
+\bugonpage B266, new code between lines 31 and 32 (8/7/87)
+
+\ninepoint
+\noindent\hskip10pt{\bf while} $\\{cur\_s}>-1$ {\bf do}\par
+\noindent\hskip20pt{\bf begin if} $\\{cur\_s}>0$ {\bf then}
+  \\{dvi\_out}(\\{pop})\par
+\noindent\hskip20pt{\bf else begin} \\{dvi\_out}(\\{eop});
+  \\{incr}(\\{total\_pages})\par
+\noindent\hskip30pt{\bf end};\par
+\noindent\hskip20pt\\{decr}(\\{cur\_s});\par
+\noindent\hskip20pt{\bf end};\par
+
+\bugonpage B285, line 21 (4/28/88)
+
+\noindent\tenpoint
+is subsidiary to the \\{nucleus} field of some noad; the dot is replaced by
+`|_|' or `|^|' or `|/|' or `|\|' if $p$ is\cutpar
+
+\bugonpage B338, second-last line (8/19/87)
+
+\ninepoint\noindent\kern10pt
+$q\gets\\{link}(\\{head})$; $s\gets\\{head}$;
+
+\bugonpage B339, line 4 (8/19/87)
+
+\ninepoint\noindent\kern20pt
+$s\gets q$; $q\gets\\{link}(q)$;
+
+\bugonpage B339, new code to insert after line 10 (8/19/87)
+
+\ninepoint
+\noindent\kern10pt{\bf if} $o\ne0$ {\bf then}\par
+\noindent\kern20pt{\bf begin} $r\gets\\{link}(q)$; $\\{link}(q)\gets\\{null}$;
+ $q\gets\\{hpack}(q,\\{natural})$;\par
+\noindent\kern20pt$\\{shift\_amount}(q)\gets o$; $\\{link}(q)\gets r$;
+ $\\{link}(s)\gets q$;\par
+\noindent\kern20pt{\bf end};\par
+\noindent[These new lines also imply changes to the index that aren't
+ shown in this errata list.]
+
+\bugonpage B387, line 2 (5/24/88)
+
+\tenpoint\noindent
+is quite short. In the following code we set \\{hc}$[\\{hn}+2]$ to the
+impossible value 128, in order to\cutpar
+
+\bugonpage B387, line 8 (5/24/88)
+
+\ninepoint\noindent\kern10pt
+$\\{hc}[0]\gets127$; $\\{hc}[\\{hn}+1]\gets127$;
+ $\\{hc}[\\{hn}+2]\gets128$;\quad$\{\,$insert delimiters$\,\}$
+
+\bugonpage B390, lines 17--18 (5/24/88)
+
+\ninepoint\noindent\kern10pt
+$\langle\,$Enter as many hyphenation exceptions as are listed, until coming
+ to a right brace; then {\bf return\eightrm\kern.5em961}$\,\rangle$;
+
+\smallskip[The same change applies to lines 20--21, and
+to page~582.]
+
+\bugonpage B396, new line after line 34 (5/24/88)
+
+\ninepoint\noindent\kern10pt
+$\\{trie\_link}(\\{trie\_size})\gets0$;
+$\\{trie\_back}(0)\gets\\{trie\_size}$;\quad
+$\{\,$wrap around$\,\}$
+
+\bugonpage B396, bottom line (12/12/87)
+
+\ninepoint\noindent\hskip10pt
+$\\{trie\_link}(0)\gets0$; $\\{trie\_char}(0)\gets0$;
+ $\\{trie\_op}(0)\gets\\{min\_quarterword}$;
+
+\bugonpage B397, lines 15--17 (5/24/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin} $c\gets\\{trie\_c}[p]$;\par\noindent\kern10pt
+{\bf if} $c<\\{trie\_min}$ {\bf then} $\\{trie\_min}\gets c$;\par\noindent\kern10pt
+{\bf if} $\\{trie\_min}=0$ {\bf then} $z\gets\\{trie\_link}(\\{trie\_size})$\par
+\noindent\kern10pt
+{\bf else} $z\gets\\{trie\_link}(\\{trie\_min}-1)$;\quad
+$\{\,$get the first conceivably good hole$\,\}$
+
+\bugonpage B400, lines 3--4 (5/24/88)
+
+\ninepoint\noindent
+$\langle\,$Enter all of the patterns into a linked trie, until coming
+ to a right brace{\eightrm\kern.5em961}$\,\rangle\equiv$
+
+\smallskip[The same change applies to page B399, lines 29--30, and
+to page~582.]
+
+\bugonpage B402, line 10 (5/24/88)
+
+\ninepoint\noindent\kern10pt
+$r\gets\\{trie\_size}$;\quad
+$\{\,$finally, we will zero out the holes$\,\}$
+
+\bugonpage B406, line 9 from the bottom (1/23/89)
+
+\ninepoint\noindent\kern30pt
+$\\{shrink\_order}(r)\gets\\{normal}$; \ $\\{delete\_glue\_ref}(q)$; \
+$\\{glue\_ptr}(p)\gets r$; \ $q\gets r$;
+
+\bugonpage B417, line 10 (1/23/89)
+
+\ninepoint\noindent\kern10pt
+$q\gets\\{new\_skip\_param}(\\{top\_skip\_code})$; \quad
+$\{\,$now $\\{temp\_ptr}=\\{glue\_ptr}(q)\,\}$
+
+\bugonpage B418, line 14 (1/23/89)
+
+\ninepoint\noindent\kern30pt
+$\\{shrink\_order}(r)\gets\\{normal}$; \ $\\{delete\_glue\_ref}(q)$; \
+$\\{glue\_ptr}(p)\gets r$; \ $q\gets r$;
+
+\bugonpage B507, line 13 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf if\/} \\{log\_opened} {\bf then} $\\{selector}\gets\\{selector}+2$;
+
+\bugonpage B527, line 21 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf if\/} \\{log\_opened} {\bf then}
+
+\bugonpage B528, line 5 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf if\/} \\{log\_opened} {\bf then}
+
+\bugonpage B547, right column (9/20/87)
+
+\eightpoint
+\leftline{\\{co\_backup}:\quad $\underline{366}$.}
+
+\bugonpage B548, right column (9/20/87)
+
+\eightpoint
+\leftline{\\{cur\_order}:\quad 366, $\underline{447}$, 448, 454, 462.}
+
+\bugonpage B548, right column (8/7/87)
+
+\eightpoint
+\leftline{\\{cur\_s}:\quad 593, $\underline{616}$, 619, 629, 640, 642.}
+
+\bugonpage B551, both columns (12/23/87)
+
+\eightpoint[Remove `372' from \\{eqtb} and put it into \\{eq\_define}.]
+
+\bugonpage B552, left column (4/28/88)
+
+\eightpoint[Insert `358' into \\{expand}.]
+
+\bugonpage B554, left column (12/23/87)
+
+\eightpoint[Remove `372' from \\{frozen\_relax}.]
+
+\bugonpage B559, new entry (12/14/88)
+
+\eightpoint\noindent
+\\{log\_opened}, 92--93, $\underline{527}$, 528, 534--535, 1265, 1333--1334.
+
+\bugonpage B559, right column (8/13/87)
+
+\eightpoint[Delete the entry for \\{low\_mem\_max}.]
+
+\bugonpage B562, left column (4/28/88)
+
+\eightpoint[Remove `358' from \\{no\_expand}.]
+
+\bugonpage B565, left column (8/7/87)
+
+\eightpoint
+\leftline{\\{pop}:\quad 584--585, $\underline{586}$, 590, 601, 608, 642.}
+
+\bugonpage B567, left column (12/23/87)
+
+\eightpoint[Insert `372' into \\{relax}.]
+
+\bugonpage B568, left column (4/28/88)
+
+\eightpoint[Move `269' from \\{save\_index} to \\{save\_level}.]
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\bugonpage C26, bottom line (7/18/87)
+
+\tenpoint\noindent
+What angle corresponds to the direction North-Northwest?
+
+\bugonpage C107, line 13 (10/7/87)
+
+{\bf pickup penrazor} xscaled \\{heavyline}
+  rotated (angle$(z_{32}-z_{31})+90$);
+
+\bugonpage C164, line 10 (4/27/88)
+
+\ninepoint\indent
+\quad $y_{\$c}=\\{top}\,y_{\$l}$; \ $y_{\$d}=y_{\$r}$; \
+ $x_{\$c}=x_{\$l}-\\{left\_jut}$; \ $x_{\$d}=x_{\$r}+\\{right\_jut}$;
+
+\bugonpage C175, line 23 (1/11/88)
+
+\ninepoint\noindent
+expand into a sequence of tokens. \
+(The language {\eightrm{SIMULA67}} demonstrated that it is\cutpar
+
+\bugonpage C241, line 11 (5/25/88)
+
+\ninepoint\indent
+{\bf numeric} $\\{ht}\0,\\{dp}\0$; \
+ $\\{ht}\0=\\{body\_height}\0$; \
+ $.5[\\{ht}\0,-\\{dp}\0]=\\{axis}\0$;
+
+\bugonpage C248, line 21 becomes two lines (1/24/89)
+
+\ninepoint\noindent
+which might not
+be numerically stable in the presence of rounding errors.)
+Another case, not really desirable, is $\\{left\_jut}=\\{right\_jut}=0$.
+
+\bugonpage C262, line 15 (12/23/88)
+
+\ninepoint\noindent
+|string base_name, base_version; base_name="plain"; base_version="1.7";|
+
+\bugonpage C271, line 12 (1/4/89)
+
+\ninepoint\noindent
+the user and \MF's primitive picture commands.
+First, some important program\cutpar
+
+\bugonpage C271, line 4 from the bottom (12/23/88)
+
+\ninepoint\noindent
+|def |^|cutdraw|| expr p = % caution: you may need autorounding=0|
+
+\bugonpage C272, lines 5 and 6 (12/23/88)
+
+\ninepoint\noindent
+|  (cut_ scaled (1+max(pen_lft,pen_rt,pen_top,pen_bot))|\par\noindent
+|   rotated theta shifted z)t_;|
+
+\bugonpage C273, lines 20 and 22 (9/26/88)
+
+\ninepoint\noindent
+|  (z_+(0,pen_top))t_=round((z+(0,pen_top))t_); z_ enddef;|\par\noindent
+|  (z_+(0,pen_bot))t_=round((z+(0,pen_bot))t_); z_ enddef;|
+
+\bugonpage C290, line 6 from the bottom (12/23/88)
+
+\ninepoint\noindent
+(2)~A throwaway variable,
+`\\{whatever}', nullifies an unwanted equation at the beginning\cutpar
+
+\bugonpage C331, just below the illustration (7/18/87)
+
+\ninepoint\noindent
+Such a pattern is, of course, rather unlikely to occur in a |gf| file,
+but |GFtoDVI| would\cutpar
+
+\bugonpage C337, line 11 (4/28/88)
+
+\ninepoint
+An online ``menu'' of the available test routines will be typed at your
+terminal\cutpar
+
+\bugonpage C346, entry for {\tt autorounding} (12/23/88)
+
+\eightpoint\indent\hskip20pt
+212, {\it262}, {\it264}, 271--272.
+
+\bugonpage C350, left column (7/6/88)
+
+\eightpoint\indent
+|Fatal| |base| |file| |error|, 226.
+
+\bugonpage C356, left column (1/11/88)
+
+\eightpoint
+SIMULA67 language, 175.
+
+\bugonpage C358, right column (2/15/88)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|yoffset|, 212, $\underline{220}$, 315, 324.
+% Volume D
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage D2, line 27 (12/14/88)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]METAFONT,\]Version\]1.7\char'23}\quad
+$\{\,$printed when \MF\ starts$\,\}$
+
+\bugonpage D36, lines 3--5 (11/6/88)
+
+\tenpoint\noindent[Delete this paragraph; it is being moved to page D349.]
+
+\bugonpage D36, line 7 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin if\/} \\{log\_opened} {\bf then} $\\{selector}\gets\\{term\_and\_log}$
+
+\bugonpage D36, line 16 (12/14/88)
+
+\ninepoint\noindent\kern50pt
+{\bf if\/} \\{log\_opened} {\bf then} \\{error};
+
+\bugonpage D66, lines 34--35 (7/9/88)
+
+\ninepoint\noindent\kern10pt
+{\bf begin if\/} $\\{hi\_mem\_min}-\\{lo\_mem\_max}\ge1998$
+ {\bf then} $t\gets\\{lo\_mem\_max}+1000$\par\noindent\kern10pt
+{\bf else} $t\gets\\{lo\_mem\_max}+1+(\\{hi\_mem\_min}-\\{lo\_mem\_max})
+\,\mathbin{\bf div}\,2$;\quad\kern-4pt
+$\{\,\\{lo\_mem\_max}+2\le t<\\{hi\_mem\_min}\,\}$
+
+\bugonpage D347, new line of code after line 5 (12/14/88)
+
+\ninepoint\noindent
+\\{log\_opened}: \\{boolean};\quad$\{\,$has the transcript file been opened?$\,\}$
+
+\bugonpage D347, line 11 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+$\\{job\_name}\gets0$; \
+$\\{log\_opened}\gets\\{false}$;
+
+\bugonpage D348, line 4 from the bottom (12/14/88)
+
+\ninepoint\noindent\kern10pt
+$\\{log\_name}\gets\\{a\_make\_name\_string}(\\{log\_file})$; \
+$\\{selector}\gets\\{log\_only}$; \
+$\\{log\_opened}\gets\\{true}$;
+
+\bugonpage D349, lines 6 and 7 (12/14/88)
+
+\tenpoint\noindent
+print error messages or even to \\{show\_context}.
+The \\{prompt\_file\_name} routine can result in a \\{fatal\_error},
+but the \\{error}
+routine will not be invoked because \\{log\_opened} will be false.
+\par\noindent\hskip10pt
+The normal idea of \\{batch\_mode} is that nothing at all should be written
+on the terminal. However, in the unusual case that
+no log file could be opened, we make an exception and allow
+an explanatory message to be seen.
+
+\bugonpage D349, lines 11--15 reduce to a single line (12/14/88)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} $\\{selector}\gets\\{term\_only}$;
+
+\bugonpage D420, bottom line (5/25/88)
+
+\ninepoint\noindent\kern30pt
+{\bf if\/} \\{txx} {\bf mod} $\\{unity}=0$ {\bf then}
+
+\bugonpage D441, delete line 2 and change line 12 as follows (5/25/88)
+
+\ninepoint\noindent
+\\{done}: {\bf if} $\\{eq\_type}(x)\ne\\{tag\_token}$ {\bf then}
+ $\\{clear\_symbol}(x,\\{false})$;\par\noindent\kern10pt
+{\bf if} $\\{equiv}(x)=\\{null}$ {\bf then} $\\{new\_root}(x)$;
+\par\noindent\kern10pt
+$\\{scan\_declared\_variable}\gets h$;
+
+\bugonpage D444, line 8 from the bottom (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf if\/} \\{log\_opened} {\bf then} $\\{selector}\gets\\{selector}+2$;
+
+\bugonpage D510, line 14 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf if\/} \\{log\_opened} {\bf then}
+
+\bugonpage D511, line 11 (12/14/88)
+
+\ninepoint\noindent\kern10pt
+{\bf if\/} \\{log\_opened} {\bf then}
+
+\bugonpage D530, new entry (12/14/88)
+
+\eightpoint\noindent
+\\{log\_opened}, 87--88, $\underline{782}$, 783, 788--789, 1023, 1205, 1208.
+
+\bugonpage D545, left column (10/31/87)
+
+\eightpoint
+\leftline{{\bf zscaled} primitive:\quad $\underline{893}$.}
+\leftline{Zabala Salelles, Ignacio Andres:\quad 812.}
+
+% volume E
+\hsize=29pc
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+\bugonpage E32, second-last line (9/20/87)
+
+\tenpoint\noindent
+after which comes `\\{math\_axis}\0; {\bf generate} |mathsy|' (which we
+won't bother to\cutpar
+
+\bugonpage E111, line 29 (10/16/88)
+
+\ninepoint\noindent
+$\\{lft}\,x_{11}={\rm hround}\,u$; \
+ $x_{1l}-x_{11}=x_{2l}-x_{12}=x_{22}-x_{2r}={\rm hround}\,1.6\\{cap\_jut}$;
+
+\bugonpage E285, bottom line (12/1/87)
+
+\rightline{\eightssi Due to Technical Developments\/\enspace\eightss(1968)}
+
+\bugonpage E333, lines 9--11 (1/9/89)
+
+\ninepoint\noindent
+$\\{lft}\,x_{1l}={\rm hround}(2.5u-.5\\{mfudged.stem})$; \
+ $x_{1l}=x_{1'l}=x_{2l}=x_{2'l}$;\par\noindent
+$\\{lft}\,x_{3l}={\rm hround}(.5w-.5\\{mfudged.stem})$; \
+ $x_5-x_3=x_3-x_1$;\par
+\line{{\bf if\/} not \\{monospace}: 
+ $r:={\rm hround}(x_5+x_1)+r-w$; {\bf fi}\hfill
+ \% change width for better fit}
+
+\bugonpage E353, lines 38--39 (8/12/87)
+
+\ninepoint
+\leftline{\kern10pt{\bf else}: {\bf fill} \\{diag\_end}$(6r,5r,1,1,5l,6l)
+ \dashto.9[z_{5l},z_{6l}]$}
+\line{\kern30pt$.\,.\,\{z_5-z_6\}\,.1[z_{5r},z_{6r}]\dashto\rm cycle$;\hfil
+ \% middle stem}
+
+\bugonpage E387, line 13 (8/12/87)
+
+\ninepoint
+\line{\kern10pt{\bf pickup} \\{tiny}.\\{nib}; \ \\{bulb}$(3,4,5)$;\hfil\% bulb}
+
+\bugonpage E413, lines 37--38 (8/12/87)
+
+\ninepoint
+\leftline{\kern10pt{\bf else}: {\bf fill} \\{diag\_end}$(6r,5r,1,1,5l,6l)
+ \dashto.9[z_{5l},z_{6l}]$}
+\line{\kern30pt$.\,.\,\{z_5-z_6\}\,.1[z_{5r},z_{6r}]\dashto\rm cycle$;\hfil
+ \% middle stem}
+
+\bugonpage E459, line 24 (8/7/87)
+
+\ninepoint\noindent[Delete the `$=$' sign between `\\{lft}' and `$x_5$'.]
+
+\bugonpage E471, line 5 (12/11/88)
+
+\ninepoint\noindent
+$x_2=\\{good}.x\,.5w$; \ $\\{center\_on}(x_2)$;
+
+\bugonpage E471, insert two lines below the rule at bottom of page (12/11/88)
+
+\ninepoint
+\line{{\bf def\/}
+\\{center\_on}({\bf expr} $x) =\null$
+{\bf if\/} not \\{monospace}:\hfill \% change width for symmetric fit}
+\leftline{\kern10pt
+ $r:=r+2x-w$; \ $w:=2x$; \ {\bf fi} {\bf enddef};}
+
+\bugonpage E477, line 20 (12/11/87)
+
+\ninepoint\noindent
+$x_4=x_8=\\{good}.x\,.5w$; \ $\\{center\_on}(x_4)$; \
+$x_2=w-x_6=\\{good}.x(x_4+a)$;
+
+\bugonpage E483, third line of elementary division operator (12/11/88)
+
+\ninepoint\noindent
+$x_3-.5\\{dot\_size}={\rm hround}(.5w-.5\\{dot\_size})$; \
+$\\{center\_on}(x_3)$;
+
+\bugonpage E485, line 4 (8/7/87)
+
+\ninepoint\noindent[Delete the `$=$' sign between `\\{lft}' and `$x_5$'.]
+
+\bugonpage E487, line 17 (8/4/88)
+
+\ninepoint\line{%
+{\bf fill} \\{fullcircle} scaled$\,(\\{bold}+3.8\\{dw}+\\{eps})\,$%
+ shifted$\,(.5[z_4,z_8])$;\hfill\% dot}
+\smallskip\noindent[Also remove page 487 from the index entry for
+\\{dot\_size}, and add it to the entries for \\{bold} and \\{dw}.]
+
+\bugonpage E515, lines 5 and 12 (12/11/88)
+
+\ninepoint\noindent
+$.5[x_1,x_2]=x_3=\\{good}.x\,.5w$; \
+$\\{center\_on}(x_3)$; \ $\\{lft}\,x_1={\rm hround}(.5w-u*{\rm sqrt}48)$;
+
+\bugonpage E515, line 21 (1/23/89)
+
+\ninepoint\noindent
+{\bf labels}$(5,6)$; \ \\{zero\_width}; \ {\bf endchar\/};
+\smallskip\noindent[Also put labels `{\tt5}' and `{\tt6}' on the
+upper right figure, page E514.]
+
+\bugonpage E521, lines 4 and 14 (12/12/88)
+
+\ninepoint\noindent
+$x_1=x_2=\\{good}.x\,.5w$; \
+$\\{center\_on}(x_1)$; \ $\\{lft}\,x_3={\rm hround}\,u$; \ $x_4=w-x_3$;
+
+\bugonpage E537, line 6 (12/11/88)
+
+\ninepoint\noindent
+$x_1=x_2=x_3=x_4$; \
+$x_1-.5\\{stem}={\rm hround}(.5w-.5\\{stem})$; \
+$\\{center\_on}(x_1)$;
+
+\bugonpage E537, line 19 (12/11/88)
+
+\ninepoint\noindent
+$x_1=x_2=x_3$; \
+$x_1-.5\\{stem}={\rm hround}(.5w-.5\\{stem})$; \
+$\\{center\_on}(x_1)$;
+
+\bugonpage E539, line 4 (12/11/88)
+
+\ninepoint\noindent
+$x_1=x_4=x_{30}=x_{33}=\\{good}.x\,.5w$; \ $\\{center\_on}(x_1)$;
+
+\bugonpage E539, line 21 (12/11/88)
+
+\ninepoint\noindent
+$x_1=x_4=\\{good}.x\,.5w$; \ $\\{center\_on}(x_1)$;
+
+\bugonpage E541, line 4 (12/11/88)
+
+\ninepoint\noindent
+$x_1=x_5=\\{good}.x\,.5w$; \ $\\{center\_on}(x_1)$;
+
+\bugonpage E541, line 17 (12/11/88)
+
+\ninepoint\noindent
+$x_1=x_{10}=\\{good}.x\,.5w$; \ $\\{center\_on}(x_1)$;
+
+\bugonpage E550, new line after line 23 (8/15/87)
+
+\ninepoint\noindent\kern10pt
+{\bf forsuffixes} $\hbox{\$}=\\{notch\_cut},\\{cap\_notch\_cut}$:
+ {\bf if\/} $\hbox{\$}<3$: $\hbox{\$}:=3$; {\bf fi endfor}
+\smallskip\noindent
+[To make room for this, combine lines 38 and 39 into a single line.]
+
+\bugonpage E550, line 29 (7/9/88)
+
+\ninepoint\noindent\hskip10pt
+{\bf \def\_{\kern.04em\vbox{\hrule width.3em height .6pt}\kern.08em}%
+define\_whole\_vertical\_blacker\_pixels}$(\\{vair},\\{bar},\\{slab},
+ \\{cap\_bar},\\{cap\_band})$;
+
+\bugonpage E572, new entry at bottom (12/11/88)
+
+\eightpoint\noindent
+\\{center\_on}, $\underline{471}$, 477, 483, 515, 521, 537--541.
+\bye
+Now here are some that I will make soon!
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.nine b/Master/texmf-dist/doc/generic/knuth-errata/errata.nine
new file mode 100644
index 00000000000..f562cb0bd8a
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.nine
@@ -0,0 +1,235 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting A, 1996}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting}, Volume~A (also known as {\sl The \TeX book}),
+between 1992 and the publication of the final printed
+version of that book in September 1996.
+\looseness=-1
+
+% volume A
+
+\bugonpage A31, line 8 (3/6/95)
+
+\tenpoint\noindent
+\TeX\ begins its error messages with `|!|', and it shows what it was
+reading at the\cutpar
+
+\bugonpage A46, line 8 (1/22/95)
+
+\ninepoint\noindent
+out for
+the occasional times when the adjacent characters |aa|, |ae|, and |o/|
+should not be\cutpar
+
+\bugonpage A49, top (9/1/96)
+
+\eightpoint\noindent
+[The copy on pages 45 and 46 was significantly shortened
+in the seventeenth printing (October 1989 --- see {\tt errata.five}),
+and exercise 8.7 moved back to page 48 as a result. But the printer
+was not asked to change page 49; hence exercise 8.7 appeared twice,
+on pages 48 {\it and\/}~49, during a six-year period.]
+
+\bugonpage A282, lines 11 and 12 (4/18/96)
+
+\ninepoint\noindent
+unadorned \<box> command, except that the new box
+being appended to the vertical list is also shifted left or right by the
+specified amount.
+
+\bugonpage A285, lines 15--17 from the bottom (4/18/96)
+
+\ninepoint
+\textindent{$\bull$}|\raise|\<dimen>\<box>, |\lower|\<dimen>\<box>.\enskip
+This acts just like an unadorned \<box> command, except that the new box
+being appended to the horizontal list is also shifted up or down by the
+specified amount.
+
+\bugonpage A290, lines 4--6 from the bottom (4/18/96)
+
+\ninepoint
+\textindent{$\bull$}|\raise|\<dimen>\<box>, |\lower|\<dimen>\<box>.\enskip
+This acts just like an unadorned \<box> command, except that the new box
+being put into the nucleus is also shifted up or down by the specified amount.
+
+\bugonpage A331, bottom two lines (6/25/93)
+
+\ninepoint\noindent
+if you know that the
+enclosing box is sufficiently small; and |\leaders\vrule\vfill| works fine in
+vertical mode.
+
+\bugonpage A354, lines 19--22 (3/5/95)
+
+\ninepoint\noindent
+|\def\sett@b{\ifx\next\+\def\nxt{\afterassignment\s@tt@b\let\nxt}%|\par
+\noindent
+|  \else\let\nxt=\s@tcols\fi|\par\noindent
+|  \let\next=\relax \nxt} % turn off \outerness|\par\noindent
+|\def\s@tt@b{\let\nxt=\relax \us@false\m@ketabbox}|
+
+\bugonpage A356, lines 13--20 from the bottom (3/5/95)
+
+\ninepoint
+{\parindent=0pt
+|\def\oalign#1{\leavevmode\vtop{\baselineskip0pt \lineskip.25ex|\par
+|  \ialign{##\crcr#1\crcr}}} \def\o@lign{\lineskiplimit=0pt \oalign}|\par
+|\def\ooalign{\lineskiplimit=-\maxdimen \oalign} % chars over each other|\par
+|\def\sh@ft#1{\dimen0=.00#1ex \multiply\dimen0 by\fontdimen1\font|\par
+|  \kern-.0156\dimen0} % compensate for slant in lowered accents|\par
+|\def|^|\d||#1{{\o@lign{\relax#1\crcr\hidewidth\sh@ft{10}.\hidewidth}}}|\par
+|\def|^|\b||#1{{\o@lign{\relax#1\crcr\hidewidth\sh@ft{29}%|\par
+|    \vbox to.2ex{\hbox{\char'26}\vss}\hidewidth}}}|\par
+}
+
+\bugonpage A357, lines 7--12 (8/1/95)
+
+\ninepoint\noindent
+|\def|^|\rightarrowfill||{$\m@th \smash- \mkern-7mu|\par\noindent
+|  \cleaders\hbox{$\mkern-2mu \smash- \mkern-2mu$}\hfill|\par\noindent
+|  \mkern-7mu \mathord\rightarrow$}|\par\noindent
+|\def|^|\leftarrowfill|%
+  |{$\m@th \mathord\leftarrow \mkern-7mu|\par\noindent
+|  \cleaders\hbox{$\mkern-2mu \smash- \mkern-2mu$}\hfill|\par\noindent
+|  \mkern-7mu \smash-$}|
+
+\bugonpage A357, lines 16--20 (6/25/93)
+
+\ninepoint
+{\parindent=0pt
+|  \setbox0=\hbox{$\braceld$}%|\par
+|  \bracelu\leaders\vrule height\ht0 depth0pt\hfill\bracerd|\par
+|  \braceld\leaders\vrule height\ht0 depth0pt\hfill\braceru$}|\par
+|\def|^|\downbracefill||{$\m@th|\par
+|  \setbox0=\hbox{$\braceld$}%|\par
+|  \braceld\leaders\vrule height\ht0 depth0pt\hfill\braceru|\par
+|  \bracelu\leaders\vrule height\ht0 depth0pt\hfill\bracerd$}|\par
+\smallskip[Also delete lines 21 and 22, as the usage is no longer restricted.]
+}
+
+\bugonpage A359, line 25 (3/5/95)
+
+\ninepoint\noindent
+|\def|^|\skew||#1#2#3{{\muskip0=#1mu \mkern.5\muskip0|\par\noindent
+|    #2{\mkern-.5\muskip0{#3}\mkern.5\muskip0}\mkern-.5\muskip0}{}}|
+
+\bugonpage A360, line 5 from the bottom (3/5/95)
+
+\ninepoint\noindent
+|\def\@vereq#1#2{\lower.5pt\vbox{\lineskiplimit\maxdimen \lineskip-.5pt|
+
+\bugonpage A361, lines 19 and 20 (3/5/95)
+
+\ninepoint\noindent
+|\def|^|\bmod||{\nonscript\mskip-\medmuskip \mkern5mu|\par\noindent
+|  |^|\mathbin||{\rm mod} \penalty900 \mkern5mu \nonscript\mskip-\medmuskip}|
+
+\bugonpage A362, lines 14--18 (3/5/95)
+
+\ninepoint\noindent
+|  |^|\everycr||{\noalign{\ifdt@p \global\dt@pfalse|%
+  | \ifdim\prevdepth>-1000pt|\par\noindent
+|      \vskip-\lineskiplimit \vskip\normallineskiplimit \fi|\par\noindent
+|      \else \penalty|^|\interdisplaylinepenalty|| \fi}}}|\par\noindent
+|\def\@lign{\tabskip=0pt\everycr={}} % restore inside \displ@y|\par\noindent
+|\def|^|\displaylines||#1{\displ@y \tabskip=0pt|
+
+\bugonpage A363, lines 8--9 from the bottom (12/8/89)
+
+{\ninepoint\parindent=0pt
+|  \if@mid \dimen@=\ht0 \advance\dimen@ by\dp\z@ |%
+ |\advance\dimen@ by12\p@|\parbreak%
+|    \advance\dimen@ by\pagetotal \advance\dimen@ by-\pageshrink|
+\par}
+
+\bugonpage A364, line 5 from the bottom (4/11/96)
+
+\ninepoint\noindent
+|\def\fmtname{plain}|\par\noindent
+|\def\fmtversion{3.141592} % identifies the current format|
+
+\bugonpage A374, line 3 (3/7/95)
+
+\ninepoint\indent
+|\begingroup\aftergroup\def\aftergroup\asts\aftergroup{|
+
+\bugonpage A410, line 23 (4/18/96)
+
+\ninepoint\noindent
+|  Tema con variazione \(su un tema differente)|
+\smallskip\eightpoint\noindent
+(This implies a corresponding correction to page 411.)
+
+\bugonpage A451, line $16$ (8/8/93)
+
+\ninepoint\noindent
+But when plain \TeX\ is tried on the name of a famous ^{Welsh} village,
+
+\bugonpage A462, right column (3/5/95)
+
+\def\cong{\mathrel{\mathpalette\OvOreq\sim}} % congruence sign, index version
+\def\OvOreq#1#2{\lower.5pt\vbox{\baselineskip0pt\lineskip-.0pt
+    \ialign{$#1\hfil##\hfil$\crcr#2\crcr=\crcr}}}
+\eightpoint
+|\cong| ( $\cong$ ), 151, $\underline{360}$, 436.
+
+\bugonpage A463, right column (6/25/93)
+
+\eightpoint
+direct sum, {\sl see\/} |\oplus|.
+
+\bugonpage A464, left column (6/25/93)
+
+\eightpoint
+|\downbracefill| (\hbox to 4em{\downbracefill}), 225--226, $\underline{357}$.
+
+\bugonpage A483, lines 15--21 (4/29/96)
+
+\tenpoint
+\begintt
+email: {\tt TUG@tug.org}
+internet: {\tt http://www.tug.org/}
+}
+\endtt
+Don't delay, subscribe today! That address again is
+
+\smallskip
+{\obeylines
+\TeX\ Users Group
+email: {\tt TUG\char`\@ tug.org}
+internet: {\tt http://www.tug.org/}
+}
+
+\bye
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.one b/Master/texmf-dist/doc/generic/knuth-errata/errata.one
new file mode 100644
index 00000000000..471971958c3
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.one
@@ -0,0 +1,751 @@
+% Bugs (sigh) in The TeXbook
+
+\input manmac
+\proofmodefalse
+\raggedbottom
+\output{\onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\rhead{Bugs in {\sl The \TeX book}, first printing}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule\line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule\nobreak\medskip}
+
+\noindent This is a list of all corrections made to {\sl The \TeX book\/}
+between the first and second printings. If your copy says `{\sl\kern-1pt Second
+printing (October 1984)\/}' on the copyright page, you've already got
+all of these things corrected. Otherwise, you're a lucky owner of the
+rare first edition; read on.
+
+\bugonpage 29, lines 31--32 (8/25/84)
+
+The underfull box that \TeX\ produces in the 1.5-inch case is really bad;
+with such narrow limits, an occasional wide space is unavoidable. But try
+
+\bugonpage 54, lines 5--6 (4/20/84)
+
+{\parfillskip=0pt
+\ddanger Appendix B shows that plain \TeX\ handles most of the accents
+by using \TeX's ^|\accent| primitive. For example, |\'#1| is equivalent
+to |{\accent19 #1}|, where\par}
+
+\bugonpage 63, seven lines below the first illustration (2/27/84)
+
+\line{points, a width of 5.5555 points, and a depth of zero;
+the letter `g' has a height}
+
+\bugonpage 72, line 35 (2/28/84)
+
+\ninepoint\noindent
+from |0pt|, but |0.00001filll| is infinitely greater than |16383.99999fill|.
+
+\bugonpage 79, line 12 (2/28/84)
+
+\ninepoint\indent
+|\hbox(6.25+1.94444)x312.0, glue set 0.5783, shifted 36.0 []|
+
+\bugonpage 98, line 24 (4/13/84)
+
+\ninepoint
+\line{and |\finalhyphendemerits=5000|. Demerits are in units of
+  ``badness squared,'' so the}
+
+\bugonpage 101, lines 29--30 (3/13/84)
+
+{\parfillskip=0pt
+\danger It's possible to control the length of lines in a much more general
+way, if simple changes to |\leftskip| and |\rightskip| aren't
+flexible enough for your\par}
+
+\bugonpage 113, bottom two lines (3/13/84)
+
+{\parfillskip=0pt
+\ddanger Notice that the first ``|%| line'' of our example says |t=10.0|;
+this is a consequence of another parameter, called ^|\topskip|. Glue
+disappears at a page break, but\par}
+
+\bugonpage 124, eighth-last line (8/25/84)
+
+\ninepoint
+{\parfillskip=0pt\noindent
+discarded, |\box100| will
+be void after the |\vsplit|. And if\/ |\box100| was void before the\par}
+
+\bugonpage 131, display in exercise 16.8 (3/16/84)
+
+\indent
+|If$ x = y$, then $x$ is equal to $y.$|
+
+\bugonpage 170, table in middle of the page (2/12/84)
+
+\ninepoint
+$$\baselineskip0pt\lineskip0pt
+\halign to\hsize
+ {\strut\hbox to\parindent{\it#\hfil}& % for the legend "Left atom"
+  #\hfil\quad& % for the row labels
+  #\hfil\tabskip 0pt plus 10pt& % for the rule at the left
+  \hbox to 25pt{\tt\hss#\hss}& % for column 1
+  \hbox to 25pt{\tt\hss#\hss}& % for column 2
+  \hbox to 25pt{\tt\hss#\hss}& % for column 3
+  \hbox to 25pt{\tt\hss#\hss}& % for column 4
+  \hbox to 25pt{\tt\hss#\hss}& % for column 5
+  \hbox to 25pt{\tt\hss#\hss}& % for column 6
+  \hbox to 25pt{\tt\hss#\hss}& % for column 7
+  \hbox to 25pt{\tt\hss#\hss}& % for column 8
+  #\hfil\tabskip0pt\cr % for the rule at the right
+\noalign{\vskip-6pt} % it just happens that there's extra white space
+&&&&\multispan7\hss\it Right atom\hss\cr
+\noalign{\vskip3pt}
+&&&\rm Ord&\rm Op&\rm Bin&\rm Rel&\rm Open&\rm Close&\rm Punct&\rm Inner\cr
+\noalign{\vskip2pt}
+\omit&&\multispan{10}\leaders\hrule\hfil\cr
+\omit\vbox to 2pt{}&&\vrule&&&&&&&&&\vrule\cr
+&Ord&\vrule&0&1&(2)&(3)&0&0&0&(1)&\vrule\cr
+&Op&\vrule&1&1&*&(3)&0&0&0&(1)&\vrule\cr
+&Bin&\vrule&(2)&(2)&*&*&(2)&*&*&(2)&\vrule\cr
+Left&Rel&\vrule&(3)&(3)&*&0&(3)&0&0&(3)&\vrule\cr
+atom&Open&\vrule&0&0&*&0&0&0&0&0&\vrule\cr
+&Close&\vrule&0&1&(2)&(3)&0&0&0&(1)&\vrule\cr
+&Punct&\vrule&(1)&(1)&*&(1)&(1)&(1)&(1)&(1)&\vrule\cr
+&Inner&\vrule&(1)&1&(2)&(3)&(1)&0&(1)&(1)&\vrule\cr
+\omit\vbox to 2pt{}&&\vrule&&&&&&&&&\vrule\cr
+\omit&&\multispan{10}\leaders\hrule\hfil\cr}$$
+
+\bugonpage 173, line 11 (1/2/84)
+
+\indent|Clearly $a_i<b_i$ for~$i=1, 2, \ldots, n$.|
+
+\bugonpage 176, bottom two lines (7/20/84)
+
+\def\chapno{ 18} \exno=23 % for exercise 18.24!
+\dangerexercise Typeset the display \ \lower12pt\null
+$\tenpoint\smash{\displaystyle
+\left\lgroup\matrix{a&b&c\cr d&e&f\cr}\right\rgroup
+  \left\lgroup\matrix{u&x\cr v&y\cr w&z\cr}\right\rgroup
+}$, \
+using ^|\lgroup| and ^|\rgroup|.
+
+\bugonpage 189, line 18 (2/13/84)
+
+\ninepoint\noindent
+{\parfillskip=0pt
+when there is an overlap.] \ If $e=0$ and if there is an |\leqno|,
+the equation number is\par}
+
+\bugonpage 204, line 31 (2/13/84)
+
+\ninepoint\noindent
+of\/ |\a| is delimited by a left brace.
+
+\bugonpage 212, line 23 (7/8/84)
+
+\ninepoint\noindent
+it equals~2.) \
+Similarly, ^|\tracingmacros||=2| will trace |\output|, |\everypar|, etc.
+
+\bugonpage 216, first five lines (8/25/84)
+
+\ddanger Expanded definitions that are made with |\edef| or |\xdef| continue
+to expand tokens until only unexpandable tokens remain, except that
+token lists produced by `^|\the|' are not expanded further. Furthermore
+a token following `^|\noexpand|' will not be expanded, since its ability
+to expand has been nullified. These two operations can be used to control
+^^{expansion, avoiding} what gets expanded and what doesn't.
+
+\bugonpage 219, simplification of line 18 (2/15/84)
+
+\ninepoint\indent
+|  \advance\count0 by\count2 \hexdigit}}|
+
+\bugonpage 223, lines 3--4 (3/13/84)
+
+{\parfillskip=0pt
+\ddanger Chapters 24 to 26 present summaries of all \TeX's operations
+in all modes, and when those summaries mention a `\<box>' they mean one
+of the seven\par}
+
+\bugonpage 242, line 29 (1/2/84)
+
+\ninepoint\noindent
+{\parfillskip=0pt
+a relation, the solution is to insert `|{}|' ^^{lbrace rbrace}
+at the beginning of the right-hand formula; \TeX
+\par}
+
+\bugonpage 245, line 24 (2/15/84)
+
+\ninepoint\noindent
+of a box that spans columns $i$ through~$j$,
+hence the glue in such a box might shrink.
+
+\bugonpage 248, the fourth dangerous bend (2/15/84)
+
+{\parfillskip=0pt
+\ddanger You have to be careful with the use of |&| and ^|\span| and ^|\cr|,
+because these tokens are intercepted by \TeX's scanner even when it is
+not expanding macros.\par}
+
+\bugonpage 249, lines 20--26 (2/15/84)
+
+\ninepoint\noindent
+line (see Chapter~9).
+If you don't want a~|\cr| at the end of a certain line,
+just type `|%|' and the corresponding |\cr|
+will be ``commented out.'' ^^{percent} \ (This special mode doesn't
+work with ^|\+| lines, since |\+| is a macro whose argument is delimited
+by the token `|\cr|', not simply by a token that has the same meaning
+as~|\cr|.  ^^{delimited arguments} But you can redefine |\+| to overcome
+this hurdle, if you want to. For example, define a macro |\alternateplus|
+that is just like |\+| except that its argument is delimited by the active
+character |^^M|; then include the command `|\let\+=\alternateplus|' as
+part of\/ |\obeylines|.)
+
+\bugonpage 253, lines 28--32 (4/25/84)
+
+\ninepoint\noindent
+vertical list at what it thinks is the best place, and at such times
+it enters internal vertical mode and begins to read the commands in the
+current |\output| routine. When the output routine begins, ^|\box255|
+contains the page that \TeX\ has completed; the output routine is supposed to
+do something with this vbox. When the output routine ends, the list of
+items that it has constructed in internal vertical mode is placed just%
+{\parfillskip=0pt\par}
+
+\bugonpage 254, lines 1--13 (3/13/84)
+
+\ddanger \TeX's primitive command |\shipout|\<box> is what actually
+causes output. It sends the contents of the box to the |dvi| file,
+which is \TeX's main output file; after \TeX\ has finished,
+the ^|dvi| file will contain a compact device-independent encoding of
+instructions that specify exactly what should be printed.  When a
+box is shipped out, \TeX\ displays the values of\/ |\count0| through
+|\count9| on your terminal, ^^|\count0| as explained in Chapter~15; these
+ten counters are also recorded in the |dvi| file, where they can be used
+to identify the page. All of the ^|\openout|, ^|\closeout|, and ^|\write|
+commands that appear inside of the \<box> are performed in their natural
+order as that box is being shipped out. Since a |\write| command
+expands macros, as explained in Chapter~21, \TeX's scanning mechanism
+might detect syntax errors while a |\shipout| is in progress. If
+^|\tracingoutput| is nonzero at the time of a |\shipout|, the contents
+of the \<box> being shipped are written into your log file in symbolic
+form. You can say |\shipout| anywhere, not only in an output routine.
+
+\bugonpage 255, line 33 (4/25/84)
+
+\ninepoint\indent
+|\nointerlineskip|
+
+
+\bugonpage 256, starting with line $-17$ (11/1/83)
+
+\ninepoint
+\textindent{6)} Finally, the ^|\dosupereject| macro is designed to clear
+out any insertions that have been held over, whether they are illustrations
+or footnotes or both: ^^|\insertpenalties| ^^|\supereject|
+\begintt
+\ifnum\insertpenalties>0
+  \line{} \kern-\topskip \nobreak
+  \vfill\supereject\fi
+\endtt
+The mysterious negative ^|\kern| here cancels out the natural space of the
+^|\topskip| glue that goes above the empty |\line|; that empty line box
+prevents the ^|\vfill| from disappearing into a page break.  The vertical
+list that results from |\dosupereject| is placed on \TeX's list of things
+to put out next, just after the straggling insertions have been
+reconsidered as explained in Chapter~15. Hence another super-eject will
+occur, and the process will continue until no insertions remain.
+
+\bugonpage 262, line 14 (2/12/84)
+
+\ninepoint\indent
+|\def\endindex{\mark{}\break\endgroup}|
+
+\bugonpage 262, lines 34 and 35 (2/12/84)
+
+\ninepoint\noindent
+if\/ |\next| is `|\endindex|',
+the next commands executed will be `|\vfill|\allowbreak
+|\mark{}|\allowbreak|\break|\allowbreak|\endgroup|';
+otherwise the line will be treated as a main entry.
+
+\bugonpage 269, line 23 becomes two lines (8/25/84)
+
+\ninepoint\noindent
+tokens like |+|$_{12}$;
+(3)~keywords like \[pt]; (4)~control sequence names like |\dimen|;
+or (5)~the special symbols |{|, |}|, |$|.
+
+\bugonpage 274, line 24 (2/15/84)
+
+\ninepoint\indent
+|\lineskip|\quad(interline glue if\/ |\baselineskip| isn't feasible)
+
+\bugonpage 289, slight clarification on lines 39--41 (3/10/84)
+
+\ninepoint
+A \<math character> defines a 15-bit number either by specifying it
+directly with ^|\mathchar| or in a previous ^|\mathchardef|, or by
+specifying a 27-bit |\delimiter| value; in the latter case, the least
+significant 12~bits are discarded.
+
+
+\bugonpage 307, a slightly more explicit answer (11/3/83)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss6.3.\enspace}%
+It represents the heavy bar that shows up in
+your output. \ (This bar wouldn't be present if\/ ^|\overfullrule| had been
+set to |0pt|, nor is it present in an underfull box.)
+
+\bugonpage 313, first four lines (3/13/84)
+
+{\ninepoint\parfillskip=0pt
+\ansno12.17:
+ You get `A' at the extreme left and `puzzle.\null' at the extreme right,
+because the space between words has the only stretchability that is finite;
+the infinite stretchability cancels out. \ (In this case, \TeX's rule
+about ^{infinite glue} differs from what you would get in the limit if the
+value of $1\,{\rm fil}$ were finite but getting larger and larger.
+The true\par}
+
+\bugonpage 315, first three lines (3/13/84)
+
+\ninepoint
+\ansno14.14:
+ Just say |\parfillskip|\stretch|=|\stretch|\parindent|. Of course,
+\TeX\ will not be able to find appropriate line breaks unless each
+paragraph is sufficiently long or sufficiently lucky; but with an
+appropriate text, your output will be immaculately
+symmetrical.{\parfillskip=\parindent\par}
+
+\bugonpage 324, line 16 (2/15/84)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss18.41.\enspace}%
+|$$\{\underbrace{\overbrace{\mathstrut a,\ldots,a}|
+
+\bugonpage 324, first line of answer 18.44 (4/11/84)
+
+\ninepoint
+\ansno18.44:
+ |$$\mathop{{\sum}'}_{x\in A}f(x)\mathrel{\mathop=^{\rm def}}|
+
+\bugonpage 333, beginning of the final paragraph (12/19/83)
+
+\ninepoint
+{\sl Note:\/} The stated preamble solves the problem and demonstrates
+that \TeX's line-breaking capability can be used within tables. But this
+particular table is not really a good example of the use of\/ |\halign|,
+because \TeX\ could typeset it directly, using ^|\everypar| in an
+appropriate manner to set up the hanging indentation, and using |\par|
+instead of\/ |\cr|. For example, one could say
+
+\bugonpage 341, the bottom line was left out! (2/9/84)
+
+\line{Footline\quad\dotfill\quad Page 1009}
+
+\bugonpage 345, top three lines (1/26/84)
+
+\ninepoint{\noindent\parfillskip=0pt
+A mathcode is relevant only when the corresponding category code is
+11 or~12; therefore many of these codes will rarely be looked at. For
+example, the math code for |^^M| specifies the character |\oplus|,
+but it's hard to imagine a user who would want |^^M|\par}
+
+\bugonpage 345, line 31 (2/29/84)
+
+\ninepoint\noindent
+|\delcode`\<="26830A    \delcode`\\="26E30F    \delcode`\>="26930B|
+
+\bugonpage 347, lines 1 and 2 (3/16/84)
+
+\ninepoint\noindent
+|\count18=3  % this counter allocates math families 4, 5, 6, ...|\hfil\break
+|\count19=255 % this counter allocates insertions 254, 253, 252, ...|
+
+\bugonpage 350, line 9 from the bottom (3/16/84)
+
+\ninepoint\noindent
+font, whose information does not have to be loaded again.
+
+\bugonpage 354, line 5 (6/7/84)
+
+\ninepoint\noindent
+|\def\ialign{\everycr={}\tabskip=0pt \halign} % initialized \halign|
+
+\bugonpage 355, lines 19--21 (7/3/84)
+
+\ninepoint\noindent
+subdivision in a document; to use it, you say
+`|\beginsection|\<section title>' followed by a blank line (or~|\par|).
+The macro first emits glue and penalties, designed to start a new page
+if the present page is nearly full; then it makes a ^|\bigskip| and
+puts the section{\parfillskip=0pt\par}
+
+\bugonpage 355, lines 27--29 (7/3/84)
+
+\ninepoint\noindent
+|\outer\def\beginsection#1\par{\vskip0pt plus.3\vsize\penalty-250|
+\par\noindent
+|  \vskip0pt plus-.3\vsize\bigskip\vskip\parskip|
+\par\noindent
+|  \message{#1}\leftline{\bf#1}\nobreak\smallskip\noindent}|
+
+\bugonpage 355, line 37 (4/24/84)
+
+\ninepoint\noindent
+|\outer\def\proclaim #1. #2\par{\medbreak|
+
+\bugonpage 356, seven lines from the bottom (4/11/84)
+
+\ninepoint\noindent
+|\def|^|\TeX||{T\kern-.1667em \lower.5ex\hbox{E}\kern-.125em X}|
+
+\bugonpage 359, starting with line 2 (11/16/83)
+
+\ninepoint
+\beginlines
+|\mathchardef\ldotp="602E\mathchardef\cdotp="6201\mathchardef\colon="603A|
+|\def\ldots{\mathinner{\ldotp\ldotp\ldotp}}|
+|\def\cdots{\mathinner{\cdotp\cdotp\cdotp}}|
+|\def\vdots{\vbox{\baselineskip=4pt \lineskiplimit=0pt|
+|    \kern6pt \hbox{.}\hbox{.}\hbox{.}}}|
+|\def\ddots{\mathinner{\mskip1mu\raise7pt\vbox{\kern7pt\hbox{.}}\mskip2mu|
+|    \raise4pt\hbox{.}\mskip2mu\raise1pt\hbox{.}\mskip1mu}}|
+\endlines
+
+\bugonpage 359, starting with line 19 (11/3/83)
+
+{\ninepoint\parindent=0pt
+|\def|^|\overbrace|%
+  |#1{\mathop{\vbox{\ialign{##\crcr\noalign{\kern3pt}|\parbreak%
+|     \downbracefill\crcr\noalign{\kern3pt\nointerlineskip}|\parbreak%
+|     $\hfil\displaystyle{#1}\hfil$\crcr}}}|^|\limits||}|
+
+|\def|^|\underbrace||#1{\mathop{\vtop{\ialign{##\crcr|\parbreak%
+|     $\hfil\displaystyle{#1}\hfil$\crcr|%
+  |\noalign{\kern3pt\nointerlineskip}|\parbreak%
+|     \upbracefill\crcr\noalign{\kern3pt}}}}\limits}|
+}
+
+\bugonpage 359, seventh line from the bottom (2/29/84)
+
+\ninepoint\noindent
+|\def\backslash{\delimiter"026E30F }   \def\bracevert{\delimiter"000033E }|
+
+\bugonpage 361, line 3 (8/17/84)
+
+\ninepoint\noindent
+
+|\def\buildrel#1\over#2{\mathrel{\mathop{\null#2}\limits^{#1}}}|
+
+\bugonpage 363, line 10 (4/26/84)
+
+\ninepoint\noindent
+|  \ifhmode\edef\@sf{\spacefactor=\the\spacefactor}\/\fi|
+
+\bugonpage 364, starting with line 10 (11/1/83)
+
+{\ninepoint\parindent=0pt
+|\def\dosupereject{\ifnum\insertpenalties>0 % something is being held over|%
+\parbreak
+|  \line{}\kern-\topskip\nobreak\vfill\supereject\fi}|
+}
+
+\bugonpage 364, line 28 (7/8/84)
+
+\ninepoint\noindent
+|  \tracingmacros=2 \tracingparagraphs=1 \tracingrestores=1 |
+
+\bugonpage 370, line 7 (3/16/84)
+
+\ninepoint\noindent
+information about the \TeX\ Users Group.)
+
+\bugonpage 374, line 23 (7/8/84)
+
+\ninepoint
+\line{log file when |\tracingmacros=2| and
+  |\tracingcommands=2|. One of the important ways}
+
+\bugonpage 379, line 1 (1/12/84)
+
+\ninepoint\noindent
+A particular item can be selected by its position number from the left:
+
+\bugonpage 381, line 6 (2/12/84)
+
+\ninepoint\indent
+|\newcount\lineno % the number of file lines listed|
+
+\bugonpage 381, lines 24 and 25 (12/15/83)
+
+\ninepoint
+{\parfillskip=0pt
+Instead of listing a file verbatim, you might want to define a |\verbatim|
+macro such that `|\verbatim{$this$|{\tt\ is }|{\it!}}|' yields
+`|$this$|{\tt\ is }|{\it!}|'. It's somewhat\par}
+
+\bugonpage 385, lines 22 and 23 (1/12/84)
+
+\ninepoint\noindent
+macro, a parameter, or a token list
+variable; (b)~when \TeX\ must determine whether the token
+|&|~or ^|\span| ^^{ampersand}
+or ^|\cr| or~^|\crcr| is the end of an entry within an ^{alignment}.
+
+\bugonpage 387, two paragraphs in right column (1/18/84)
+
+\setbox0=\vbox{
+\eightpoint
+\tolerance=9999
+\hbadness=2300
+\finalhyphendemerits=3000000
+\doublehyphendemerits=1000000
+\parskip=1pt
+\parindent=1.5em
+\frenchspacing
+\hsize=166.8125pt
+\def\\#1{\raise.5pt\hbox{$\scriptscriptstyle
+    \ifx#1`\langle\!\langle\else\rangle\!\rangle\fi$}% Spanish quote marks
+  \ifx#1`\nobreak\hskip0pt \fi} % allow hyphenation
+\item{A.} Exactamente. Pero los profesores son tan conservadores
+que temer\'\i an espantar al tipo de estudiante \\`apisonadora\\'
+que hace lo que le proponen para casa, obe\-dien\-te\-mente y de forma
+mec\'anica. Adem\'as, no creo que les gustase el trabajo adicional
+de calificar respuestas a preguntas abiertas.
+
+\item{}La forma tradicional es dejar la parte creativa para los cursos
+altos. Durante diecisiete a\~nos o m\'as se ense\~na al es\-tu\-diante a
+aprobar, luego de golpe, cerca de la graduaci\'on, se le pide que haga
+algo original.
+
+}\rightline{\box0}
+
+\bugonpage 395, lines 21 and 22 (1/12/84)
+
+\ninepoint\noindent
+{\parfillskip=0pt
+Notice that the macros need to do their own checking for ligatures, and
+they also take appropriate actions when a paragraph begins with an opening
+quote.  Since |\kern|\par}
+
+\bugonpage 399, line 1 (1/10/84)
+
+\ninepoint
+{\parfillskip=0pt
+Inside the output routine, |\box\footins| will now be a vbox of hboxes, and
+\par}
+
+\bugonpage 399, line 9 (2/28/84)
+
+\ninepoint\indent
+|.\hbox(7.6359+0.0)x269.62617 []|
+
+\bugonpage 407, line 4 (6/10/84)
+
+\ninepoint\noindent
+|\beginlinemode| and |\beginparmode| are defined to initiate these
+modes; and another%
+{\parfillskip=0pt\par}
+
+\bugonpage 408, line 15 (12/14/83)
+
+\noindent
+|    P. O. Box 1009, Haga Alto, CA 94321 USA}|
+
+\smallskip\noindent\ninepoint
+[Also change the ZIP code in the return address on the envelope
+illustrated at the bottom of page 405.]
+
+\bugonpage 409, line 5 (2/18/84)
+
+\ninepoint\noindent
+|\font\twelveit=cmti10 at 12pt  % (a cheap substitute for cmti12)|
+
+\bugonpage 417, last six lines (8/25/84)
+
+\ninepoint\noindent
+^|\parskip|
+of |0pt| |plus|~|.8pt| between adjacent entries, and since there is room for
+more than 50 lines per column; therefore the |manmac| balancing routine tries
+to make both the top and bottom baselines agree at the end of the index.
+In applications where the glue is not so flexible it would be more
+appropriate to let the right-hand column be a little short; the best
+way to do this is probably to replace the command `|\unvbox3|' by
+`|\dimen2=|^|\dp||3| |\unvbox3| |\kern-\dimen2| ^|\vfil|'.
+
+\bugonpage 422, lines 24--26 (2/9/84)
+
+\ninepoint\noindent
+(The last two lines use |\d@nger| and |\dd@nger|, which are non-|\outer|
+equivalents of\/ |\danger| and |\ddanger|; such duplication is necessary
+because control sequences of type ^|\outer| cannot appear within a |\def|.)
+
+\bugonpage 428, in the table of sixteen basic fonts (12/19/83)
+
+\ninepoint\noindent
+[The special fonts called |cmi10| and |cmi7| and |cmi5| should really be
+called |cmmi10| and |cmmi7| and |cmmi5|.]
+
+\bugonpage 433, last eight lines (8/17/84)
+
+\noindent
+explained in Appendix~G\null. If you want to increase
+the number of parameters past the number that actually appear in a font's
+metric information file, you can assign new values immediately after that font
+has been loaded.  For example, if some font |\ff| with seven parameters
+has just entered \TeX's memory, the command |\fontdimen13\ff=5pt| will set
+parameter number~13 to $5\pt$; the intervening parameters, numbers 8--12,
+will be set to zero. You can even give more than seven parameters to
+^|\nullfont|, provided that you assign the values before any actual fonts
+have been loaded.
+
+\bugonpage 445, line 6 (11/11/83)
+
+\ninepoint
+\line{if $(a-{1\over2}\theta)-
+\bigl(h(z)-v\bigr)<\varphi$, increase~$v$ by the difference. Finally
+construct a vbox of}
+
+\bugonpage 449, line 12 (1/18/84)
+
+\line{immediately clear why the `n' should
+be attached to the `e' in one case but not}
+
+\bugonpage 459, left column, line 2 (1/18/84)
+
+\eightpoint
+al-Khw\^arizm\^\i, abu Ja`far Mu\d{h}ammad
+
+\bugonpage 460, index entry for Beethoven (8/16/84)
+
+\eightpoint
+Change `von' to `van'.
+
+\bugonpage 461, third line in left column (8/25/84)
+
+\eightpoint The entry for |\box255| should not be indented.
+
+\bugonpage 461, index entry for boxed material (8/2/84)
+
+\eightpoint Add `{\it 420}'.
+
+\bugonpage 462, index entry for {\tt\char`\\colon} (11/16/83)
+
+\eightpoint Add page \underbar{359} to this list.
+
+\bugonpage 462, right column, third-last line (5/21/84)
+
+\eightpoint\indent
+[Change `crochets' to `crotchets'; then move this entry down two lines.]
+
+\bugonpage 463, right column, line 16 (5/20/84)
+
+\eightpoint\indent
+design size, 16--17, 213.
+
+\bugonpage 464, index entry for {\tt\char`\\dump} (1/10/84)
+
+\eightpoint Add page {\it 344\/} to this list.
+
+\bugonpage 464, right column, line 5 (1/5/84)
+
+\eightpoint
+Dvo\v r\'ak, Anton\'\i n Leopold, 409.
+
+\bugonpage 464, index entry for {\tt\char`\\end} (8/25/84)
+
+\eightpoint Page number 264 should be underlined.
+
+\bugonpage 465, index entry for {\tt\char`\\everydisplay} (8/25/84)
+
+\eightpoint Add page {\it 326\/} to this list.
+
+\bugonpage 465, index entry for {\tt\char`\\filbreak} (7/3/84)
+
+\eightpoint Delete the reference to page number 355.
+
+\bugonpage 466, index entry for {\tt\char`\\footnote} (4/26/84)
+
+\eightpoint Page number 363 should be underlined.
+
+\bugonpage 467, index entry for {\tt\char`\\hidewidth} (7/3/84)
+
+\eightpoint Page number 354 should be underlined.
+
+\bugonpage 468, index entry for insertions (8/25/84)
+
+\eightpoint Add pages 115--117, 122--125 to this list.
+
+\bugonpage 469, index entry for {\tt\char`\\kern} (11/1/83)
+
+\eightpoint Add page {\it 256\/} to this list.
+
+\bugonpage 470, index entry for {\tt\char`\\limits} (11/3/83)
+
+\eightpoint Add page {\it 359\/} to this list.
+
+\bugonpage 472, right column, lines 10--11 (7/9/84)
+
+{\eightpoint
+\indent
+|\normalbaselines|\kern1pt,
+ {\it 325}, 349, $\underline{351}$, {\it 414--415}.\par
+\baselineskip=9.9pt
+\indent
+|\normalbaselineskip|\kern1pt,
+ $\underline{349}$, {\it 414--415}.\par
+}
+
+\bugonpage 472, index entry for {\tt\char`\\null} (7/3/84)
+
+\eightpoint Page number 351 should be underlined.
+
+\bugonpage 472, right column, line 28 (1/3/84)
+
+\eightpoint\indent
+\hbox to0pt{\hss\lower1pt\hbox{*}}|\nullfont|, 14, 153, 271, 433.
+
+\bugonpage 476, a new index entry (8/25/84)
+
+\eightpoint\indent
+shifted output, {\sl see\/} |\hoffset|, |\voffset|.
+
+\bugonpage 476, index entry for shriek (8/25/84)
+
+\eightpoint It should not be capitalized.
+
+\bugonpage 478, index entry for \'Swierczkowski (9/15/84)
+
+\eightpoint
+The middle name should be `S\l awomir'.
+
+\bugonpage 479, last seven lines in the left column (8/23/84)
+
+\eightpoint
+{\baselineskip=9.9pt
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingmacros|, $\underline{205}$, $\underline{212}$, 273, {\it329}.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingonline|, 121, 212, 273, $\underline{303}$.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingoutput|, $\underline{254}$, 273, {\it301--302}.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingpages|, {\it112--114}, 124, 273, $\underline{303}$.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingparagraphs|, {\it98--99}, 273, $\underline{303}$.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingrestores|, 273, $\underline{301}$, $\underline{303}$.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\tracingstats|, 273, $\underline{300}$, $\underline{303}$, {\it383}.
+}
+
+\bugonpage 479, index entry for underlined text (8/2/84)
+
+\eightpoint Add `{\sl see also\/} |\underbar|'.
+
+\bugonpage 480, index entry for {\tt\char`\\vbox} (11/1/83)
+
+\eightpoint Delete page 256 from this list.
+
+\bye
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.seven b/Master/texmf-dist/doc/generic/knuth-errata/errata.seven
new file mode 100644
index 00000000000..0866189da51
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.seven
@@ -0,0 +1,821 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 1991}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting}, Volumes A,~B, C, and D\null, between 1 January 1991 and
+15 March 1992.
+Corrections made to the softcover version of {\sl The \TeX book\/} are
+the same as corrections to Volume~A\null. Corrections to the softcover
+version of {\sl The \slMF\kern1ptbook\/} are the same as corrections
+to Volume~C\null.  Some of the corrections below have already been made in
+reprintings of the books. Changes to Volume~B refer to the fourth printing
+(1991), which differs markedly from earlier printings because it includes
+all the revisions for \TeX3.0. Changes to Volume~D refer to the third
+printing (1991), which differs markedly from earlier printings because
+it includes all the revisions for \MF\kern1pt2.0. Changes to the mini-indexes
+and master indexes of Volumes B and~D are not shown here unless they are
+not obviously derivable from what has been shown.
+Dozens of changes, too many to list
+here, have been made to Volume~E because of recent upgrades to the
+Computer Modern font source files.
+Those changes, which affect only the digitization at
+low resolution and the appearance of lowercase delta and
+some characters in the math symbols
+fonts (but not the {\tt TFM} files), are documented at
+the end of file {\tt cm85.bug}.
+\looseness=-1
+
+% volume A
+
+\bugonpage A96, lines 9--11 (9/18/91)
+
+\ninepoint
+Some ^{German} words traditionally change their spelling
+when they are split between lines. For example, `backen' becomes `bak-ken'
+and `Bettuch' becomes `Bett-tuch'. How can you instruct \TeX\ to produce
+such effects?
+
+\bugonpage A178, line 17 (11/19/91)
+
+\ninepoint
+If you say `|\phantom{|\<subformula>|}|' in any formula, plain
+\TeX\ will do its\cutpar
+
+\bugonpage A286, bottom two lines and continuing into A287 (11/21/91)
+
+\ninepoint\noindent
+stands for zero or more \<assignment>
+commands other than |\setbox|.
+If the assignments are not followed by a \<character>, where
+\<character> stands for any of the commands just discussed in the previous
+paragraph, \TeX\ treats |\accent| as if it were |\char|, except that
+the space factor is set to 1000. Otherwise the character that follows
+the assignment is accented by the character that corresponds to the
+\<8-bit number>. \ (The purpose of the intervening assignments is to
+allow the accenter and accentee to be in different fonts.) \ If the
+accent must be moved up or down, it is put into an hbox that is
+raised or lowered. Then the accent is effectively superposed on the
+character by means of kerns, in such a way that the width of the accent
+does not influence the width of the resulting horizontal list.
+Finally, \TeX\ sets |\spacefactor=1000|.
+
+\bugonpage A291, lines 6--8 (11/21/91)
+
+\ninepoint\noindent
+`|}|' may be followed by
+optional \<assignment> commands other than |\setbox|,
+after which `|$$|'~must conclude
+the display. \TeX\ will insert the |\abovedisplayskip| and
+|\belowdisplayskip| glue before and after the result of the alignment.
+
+\bugonpage A293, line 14 (9/18/91)
+
+\ninepoint\noindent
+explained in Appendix~G\null. \TeX\
+scans \<one optional space> after completing a displayed formula; this is
+usually the implicit space at the end of a line in the input file.
+
+\bugonpage A311, bottom four lines (9/18/91)
+
+\ninepoint
+\ansno12.7: 1000, except: 999 after |O|, |B|, |S|, |D|, and |J|; 1250 after the
+comma; 3000 after the exclamation point, the right-quote marks, and the
+periods. If a period had come just after the |B| (i.e., if the text had
+said `|B. Sally|'), the space factor after that period would have
+been~1000, not~3000.
+
+\bugonpage A314, lines 16--18 from the bottom (1/10/92)
+
+\ninepoint
+\ansno14.8: |ba\ck/en| and |Be\ttt/uch|, where the macros |\ck/| and |\ttt/|
+are defined by
+\begintt
+\def\ck/{\discretionary{k-}{k}{ck}}
+\def\ttt/{tt\discretionary{-}{t}{}}
+\endtt
+
+\bugonpage A354, line 8 (9/18/91)
+
+\ninepoint\noindent
+|\def\multispan#1{\omit\mscount=#1\relax\loop\ifnum\mscount>1 \sp@n\repeat}|%
+\kern-10pt\null
+
+\bugonpage A356, line 11 from the bottom (9/23/91)
+
+\ninepoint\noindent
+|  \else{\ooalign{\unhbox0\crcr\hidewidth\char'30\hidewidth}}\fi}|
+
+\bugonpage A358, line 8 from the bottom (9/18/91)
+
+\ninepoint\noindent
+|\mathchardef\mapstochar="3237 \def\mapsto{\mapstochar\rightarrow}|
+
+\bugonpage A359, line 13 (11/4/91)
+
+\ninepoint\noindent
+|\def\overrightarrow#1{\vbox{\m@th\ialign{##\crcr|
+
+\bugonpage A359, line 16 (11/4/91)
+
+\ninepoint\noindent
+|\def\overleftarrow#1{\vbox{\m@th\ialign{##\crcr|
+
+\bugonpage A359, line 19 (11/4/91)
+
+\ninepoint\noindent
+|\def\overbrace#1{\mathop{\vbox{\m@th\ialign{##\crcr\noalign{\kern3pt}|
+
+\bugonpage A359, line 22 (11/4/91)
+
+\ninepoint\noindent
+|\def\underbrace#1{\mathop{\vtop{\m@th\ialign{##\crcr|
+
+\bugonpage A359, lines 7--14 from the bottom (1/11/92)
+
+\ninepoint\noindent
+|\def\lgroup{\delimiter"462833A }      \def\rgroup{\delimiter"562933B }|%
+\par\noindent
+|\def\lmoustache{\delimiter"437A340 }  \def\rmoustache{\delimiter"537B341 }|%
+  \kern-2pt\null\par\noindent
+|\def\uparrow{\delimiter"3222378 }     \def\Uparrow{\delimiter"322A37E }|%
+\par\noindent
+|\def\downarrow{\delimiter"3223379 }   \def\Downarrow{\delimiter"322B37F }|%
+\par\noindent
+|\def\updownarrow{\delimiter"326C33F } \def\arrowvert{\delimiter"026A33C }|%
+\par\noindent
+|\def\Updownarrow{\delimiter"326D377 } \def\Arrowvert{\delimiter"026B33D }  |%
+\par\noindent
+|\def\vert{\delimiter"026A30C }        \def\Vert{\delimiter"026B30D }     |%
+\par\noindent
+|\def\backslash{\delimiter"026E30F }   \def\bracevert{\delimiter"077C33E }|
+
+\bugonpage A360, line 13 (11/19/91)
+
+\ninepoint\noindent
+|\phantom|, |\smash|, |\root|, and other
+operations. (Actually |\phantom| and |\smash| are not perfect: They
+assume that the current style is uncramped.)
+
+\bugonpage A360, line 2 from the bottom (11/4/91)
+
+\ninepoint\noindent
+|\def\c@ncel#1#2{\m@th\ooalign{$\hfil#1\mkern1mu/\hfil$\crcr$#1#2$}}|
+
+\bugonpage A361, top line (11/4/91)
+
+\ninepoint\noindent
+|\def\rlh@#1{\vcenter{\m@th\hbox{\ooalign{\raise2pt|
+
+\bugonpage A364, line 5 from the bottom (11/4/91)
+
+\ninepoint\noindent
+|\def|^|\fmtname||{plain}\def\fmtversion{3.141}|
+
+\bugonpage A377, the bottom 17 lines (9/18/91)
+
+\eightpoint\noindent\hangindent\parindent\hangafter-3
+story: Macro |\stest| decides whether or not
+a given token list register begins with
+a \<space token> as defined in Chapter~24. If so, the macro
+decides whether the token is explicit and/or funny and/or active.
+\begintt
+\newif\ifspace \newif\iffunny \newif\ifexplicit \newif\ifactive
+\def\stest#1{\funnyfalse \expandafter\s\the#1! \stest}
+\def\s{\global\explicitfalse \global\activefalse \futurelet\next\ss}
+\def\ss{\ifcat\noexpand\next\stoken\let\nxt\sx\else\let\nxt\ns\fi\nxt}
+\def\sx{\spacetrue\ifx\next\stoken\let\nxt\sss\else\let\nxt=\ssss\fi\nxt}
+\long\def\sss#1 #2\stest{\def\next{#1}%
+  \ifx\next\empty \global\explicittrue \else\testactive#1\s\fi}
+\long\def\ssss#1#2\stest{\funnytrue{\escapechar=\if*#1`?\else`*\fi\relax
+  \if#1\string#1\uccode`#1=`~ % we assume that ~ is an active character
+    \uppercase{\ifcat\noexpand#1}\noexpand~\global\activetrue
+    \else\global\explicittrue\fi
+  \else\testactive#1\s\fi}}
+\long\def\ns#1\stest{\spacefalse}
+\long\def\testactive#1#2\s{\expandafter\tact\string#1\s\tact}
+\long\def\tact#1#2\tact{\def\next{#2}\ifx\next\xs\global\activetrue
+  \else\ifx\next\empty \global\activetrue\fi\fi} \def\xs{\s}
+\endtt
+
+\bugonpage A444, lines 15--26 (3/26/91)
+
+\ninepoint
+\textindent{\bf14.}If the current item is an Ord atom,
+go directly to Rule~17 unless
+all of the following are true: The nucleus is a symbol; the subscript
+and superscript are both empty; the very next item in the math list is an
+atom of type Ord, Op, Bin, Rel, Open, Close, or Punct; and the nucleus of the
+next item is a symbol whose family is the same as the family in the present
+Ord atom. In such cases the present symbol is marked as a text symbol.
+If the font information shows a ligature between this symbol and the
+following one, using the specified family and the current size, then
+insert the ligature character and continue as specified by the font;
+in this process, two characters may collapse into a single Ord
+text symbol, and/or new Ord text characters may appear. If the font information
+shows a kern between the current symbol and the next, insert a kern item
+following the current atom.
+As soon as an Ord atom has been fully processed for ligatures and kerns,
+go to Rule~17.
+
+\bugonpage A446, lines 5 and 6 from the bottom (1/13/92)
+
+\ninepoint\noindent
+are used to change the current style just as
+in the first pass, so that both passes have the same value of~$C$ when
+they work on any particular atom.
+
+\bugonpage A447, in the parameter usage table (1/13/92)
+
+\ninepoint\noindent[Delete the entry for `$\sigma_2$'; the entry for
+`$\sigma_{17}$' moves down to the bottom of the left column.]
+
+\bugonpage A447, line 2 after the parameter usage table (1/13/92)
+
+\ninepoint\noindent
+to parameters in arbitrary families:
+Rule~17 uses |\fontdimen| parameter~2 (space) to de-\cutpar
+
+\bugonpage A467, entry for {\tt\char`\\hss} (9/18/91)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\hss}, 71--72, {\it82--83}, 233, 283, 285, 290, 442.
+
+\bugonpage A467, new subentry under hyphenation (9/18/91)
+
+\eightpoint\indent\quad
+suppressing, 93, 414, 424, 454.
+
+\bugonpage A476, right column (11/21/91)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\setbox}, 66--67, 77, 81, $\underline{120}$, 276, 279, 286,\par
+\indent\qquad 291, {\it386--392}.
+
+% volume B
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage B2, line 10 from the bottom (1/11/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]3.141\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B18, lines 21 and 22 (10/12/91)
+
+\tenpoint\noindent
+must have an \\{xchr} equivalent in the local
+character set. (This restriction applies only to preloaded strings,
+not to those generated dynamically by the user.)
+
+\bugonpage B26, new line before fourth line from bottom (1/24/92)
+
+\ninepoint\noindent\hskip20pt
+\\{nl}: \\{integer};\quad$\{\,$new-line character to restore$\,\}$
+
+\bugonpage B26, bottom line and top 3 lines of B27 (1/24/92)
+
+\ninepoint\noindent\hskip30pt
+{\bf else begin if\/} $\\{selector}>\\{pseudo}$ {\bf then}\par
+\noindent\hskip50pt
+{\bf begin} \\{print\_char}($s$); \ {\bf return};\quad
+ $\{\,$internal strings are not expanded$\,\}$\par\noindent\hskip50pt
+{\bf end};\par\noindent\hskip40pt
+{\bf if\/} ($\langle\,$Character $s$ is the current new-line
+  character{\sevenrm\kern.5em244}$\,\rangle$) {\bf then}\par\noindent\hskip50pt
+{\bf if\/} $\\{selector}<\\{pseudo}$ {\bf then}\par\noindent\hskip60pt
+{\bf begin} \\{print\_ln}; \ {\bf return}; \
+{\bf end};\par\noindent\hskip40pt
+$\\{nl}\gets\\{new\_line\_char}$; \ $\\{new\_line\_char}\gets-1$;\quad
+ $\{\,$temporarily disable new-line character$\,\}$\par\noindent\hskip40pt
+$j\gets\\{str\_start}[s]$;\par\noindent\hskip40pt
+{\bf while} $j<\\{str\_start}[s+1]$ {\bf do}\par\noindent\hskip50pt
+{\bf begin} $\\{print\_char}(\\{so}(\\{str\_pool}[j]))$; \ $\\{incr}(j)$; \
+{\bf end};\par\noindent\hskip40pt
+$\\{new\_line\_char}\gets\\{nl}$; \ {\bf return};\par\noindent\hskip40pt
+{\bf end};
+
+\bugonpage B27, lines 9 and 10 (9/19/91)
+
+\tenpoint\noindent
+{\bf 60.\quad}%
+Control sequence names, file names, and strings constructed with
+{\tt\char`\\string} might contain \\{ASCII\_code} values that can't
+be printed using \\{print\_char}. Therefore we use
+\\{slow\_print} for them:
+
+\bugonpage B27, lines 13--26 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf var} $j$: \\{pool\_pointer};\quad$\{\,$current character code
+ position$\,\}$\par\noindent\hskip10pt
+{\bf begin if\/} $(s\ge\\{str\_ptr})\lor(s<256)$ {\bf then} \\{print}(s)
+\par\noindent\hskip10pt {\bf else begin} $j\gets\\{str\_start}[s]$;\par
+\noindent\hskip20pt{\bf while} $j<\\{str\_start}[s+1]$ {\bf do}\par
+\noindent\hskip30pt{\bf begin} $\\{print}(\\{so}(\\{str\_pool}[j]))$; \
+ $\\{incr}(j)$;\par\noindent\hskip30pt
+{\bf end};\par\noindent\hskip20pt
+{\bf end};\par\noindent\hskip10pt
+{\bf end};
+
+\bugonpage B28, line 8 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+{\bf else begin} \\{slow\_print}(\\{format\_ident}); \ \\{print\_ln};
+
+\bugonpage B33, line 3 (1/11/92)
+
+\tenpoint\noindent
+recursively. A similar interlock is provided by \\{set\_box\_allowed}.
+
+\bugonpage B33, new line to come after line 14 (1/11/92)
+
+\ninepoint\noindent
+\\{set\_box\_allowed}: \\{boolean};\quad
+ $\{\,$is it safe to do a |\setbox| assignment?$\,\}$
+
+\bugonpage B33, new line to come after line 20 (1/11/92)
+
+\ninepoint\noindent\hskip10pt
+$\\{set\_box\_allowed}\gets\\{true}$;
+
+\bugonpage B36, line 12 (9/19/91)
+
+\ninepoint\noindent\hskip30pt
+{\bf begin} \\{print\_nl}({\tt\char`\"You\]want\]to\]edit\]file\]\char`\"});
+ \ \\{slow\_print}(\\{input\_stack}[\\{base\_ptr}].\\{name\_field});
+
+\bugonpage B46, lines 9 and 10 (5/24/91)
+
+\tenpoint\noindent
+arithmetic; see {\sl TUGboat \bf3},1 (March 1982), 10--27. (But the
+routines cited there must be modified to allow negative glue ratios.)
+
+\bugonpage B47, lines 2 and 3 (5/24/91)
+
+\tenpoint\noindent
+structures on a \\{memory\_word}, which contains either a (signed) integer,
+possibly scaled, or a (signed) \\{glue\_ratio}, or a small number of
+fields that are one half or one quarter of the size used\cutpar
+
+\bugonpage B177, lines 10 and 11 (9/19/91)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin} \\{print\_err}({\tt\char`\"Bad\]mathchar\char`\"});\par
+\noindent\hskip20pt
+\\{help2}({\tt\char`\"A\]mathchar\]number\]must\]be\]between\]0\]%
+ and\]32767.\char`\"})
+
+\bugonpage B196, new lines after line 11 (1/13/92)
+
+\ninepoint\noindent\hskip20pt
+{\bf if\/} $\\{align\_state}<1000000$ {\bf then}\quad
+ $\{\,$unmatched `|}|' aborts the line$\,\}$\par\noindent\hskip30pt
+{\bf begin repeat} \\{get\_token}; \ {\bf until} $\\{cur\_tok}=0$;\par
+\noindent\hskip30pt$\\{align\_state}\gets1000000$; \ {\bf goto} \\{done};\par
+\noindent\hskip30pt{\bf end};
+
+\bugonpage B208, line 21 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} \\{slow\_print}($a$); \ \\{slow\_print}($n$); \
+ \\{slow\_print}($e$);
+
+\bugonpage B214, line 14 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} \\{wlog}(\\{banner}); \\{slow\_print}(\\{format\_ident}); \
+  \\{print}({\tt\char`\"\]\]\char`\"}); \
+  \\{print\_int}(\\{day}); \
+  \\{print\_char}({\tt\char`\"\]\char`\"});
+
+\bugonpage B214, line 2 from the bottom (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+\\{print\_char}({\tt\char`\"(\char`\"}); \
+\\{incr}(\\{open\_parens}); \
+\\{slow\_print}(\\{name}); \
+\\{update\_terminal}; \
+$\\{state}\gets\\{new\_line}$;
+
+\bugonpage B234, line 22 (9/19/91)
+
+\ninepoint\noindent\hskip20pt
+\\{print}({\tt\char`\"\]in\]font\]\char`\"}); \
+\\{slow\_print}(\\{font\_name}[$f$]); \
+\\{print\_char}({\tt\char`\"!\char`\"}); \
+\\{end\_diagnostic}(\\{false});
+
+\bugonpage B267, lines 7 and 8 (9/19/91)
+
+\ninepoint\noindent\hskip20pt
+\\{print\_nl}({\tt\char`\"Output\]written\]on\]\char`\"}); \
+\\{slow\_print}(\\{output\_file\_name});\par\noindent\hskip20pt
+\\{print}({\tt\char`\"\](\char`\"}); \
+\\{print\_int}(\\{total\_pages}); \
+\\{print}({\tt\char`\"\]page\char`\"});
+
+\bugonpage B296, new lines after line 8 of section 716 (1/11/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $f<0$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} \\{decr}($n$); \ $f\gets f+\oct{200000}$;\par\noindent\hskip20pt
+{\bf end};
+
+\bugonpage B297, new lines after line 7 of section 717 (1/11/92)
+
+\ninepoint\noindent\hskip20pt
+{\bf if\/} $f<0$ {\bf then}\par\noindent\hskip30pt
+{\bf begin} \\{decr}($n$); \ $f\gets f+\oct{200000}$;\par\noindent\hskip30pt
+{\bf end};
+
+\bugonpage B348, bottom two lines (1/3/92)
+
+\tenpoint\noindent\hskip10pt
+Up to three passes might be made through the paragraph in an attempt to find at
+least one set of feasible breakpoints. On the first pass, we have
+$\\{threshold}=\\{pretolerance}$ and $\\{second\_pass}=$\cutpar
+
+\bugonpage B364, line 20 (1/3/92)
+
+\tenpoint\noindent
+{\bf 863.\quad}
+The `{\bf loop}' in the following code is performed at most
+thrice per call of \\{line\_break}, since\cutpar
+
+\bugonpage B377, insert new line after line 12 (9/19/91)
+
+\ninepoint\noindent
+\\{hyf\_bchar}:\enspace\\{halfword};\quad
+ $\{\,$boundary character after $c_n\,\}$
+
+\bugonpage B378, line 12 from the bottom (9/19/91)
+
+\ninepoint\noindent\hskip30pt
+$\\{hyf\_bchar}\gets\\{character}(s)$; \
+$c\gets\\{qo}(\\{hyf\_bchar})$;
+
+\bugonpage B378, line 9 from the bottom (1/10/92)
+
+\ninepoint\noindent\hskip30pt
+$\\{hb}\gets s$; \ \\{incr}(\\{hn}); \ $\\{hu}[\\{hn}]\gets c$; \
+$\\{hc}[\\{hn}]\gets\\{lc\_code}(c)$; \
+$\\{hyf\_bchar}\gets\\{non\_char}$;
+
+\bugonpage B378, line 5 from the bottom (9/19/91)
+
+\ninepoint\noindent\hskip30pt
+{\bf else if} $(\\{type}(s)=\\{kern\_node})\land(\\{subtype}(s)=\\{normal})$
+ {\bf then} $\\{hb}\gets s$\par\noindent\hskip40pt
+  {\bf else goto} \\{done3};
+
+\bugonpage B379, line 6 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+$j\gets\\{hn}$; \ $q\gets\\{lig\_ptr}(s)$; \
+{\bf if\/} $q>\\{null}$ {\bf then} $\\{hyf\_bchar}\gets\\{character}(q)$;
+
+\bugonpage B379, new line between lines 14 and 15 (1/10/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{odd}(\\{subtype}(s))$ {\bf then}
+$\\{hyf\_bchar}\gets\\{font\_bchar}[\\{hf}]$ {\bf else}
+$\\{hyf\_bchar}\gets\\{non\_char}$;
+
+\bugonpage B379, line 19 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{hn}<\\{l\_hyf}+\\{r\_hyf}$ {\bf then goto} \\{done1}; \
+\quad$\{\,$\\{l\_hyf} and \\{r\_hyf} are always $\ge1\,\}$
+
+\bugonpage B380, lines 9--11 from the bottom reduce to a single line (1/10/92)
+
+\ninepoint\noindent\hskip10pt
+$q\gets\\{link}(\\{hb})$; \ $\\{link}(\\{hb})\gets\\{null}$; \
+$r\gets\\{link}(\\{ha})$; \ $\\{link}(\\{ha})\gets\\{null}$; \
+$\\{bchar}\gets\\{hyf\_bchar}$;
+
+\bugonpage B436, lines 9 and 10 (3/15/92)
+
+\tenpoint
+$$\\{cur\_r}=\cases{\\{character}(\\{lig\_stack}),&if $\\{lig\_stack}>
+     \\{null}$;\cr
+  \\{font\_bchar}[\\{cur\_font}],&otherwise;\cr}$$
+except when $\\{character}(\\{lig\_stack})=\\{font\_false\_bchar}
+ [\\{cur\_font}]$. Several additional global variables are needed.
+
+\bugonpage B438, line 13 from the bottom (3/15/92)
+
+\ninepoint\noindent\hskip10pt
+$\\{cur\_q}\gets\\{tail}$; \ $\\{cur\_l}\gets\\{character}(\\{lig\_stack})$;
+
+\bugonpage B507, line 6 of section 1241 (1/11/92)
+
+\ninepoint\noindent\hskip10pt
+\\{scan\_optional\_equals};\par\noindent\hskip10pt
+{\bf if\/} \\{set\_box\_allowed} {\bf then}
+$\\{scan\_box}(\\{box\_flag}+n)$\par\noindent\hskip10pt
+{\bf else begin} \\{print\_err}({\tt\char`\"Improper\]\char`\"});
+\ \\{print\_esc}({\tt\char`\"setbox\char`\"});\par\noindent\hskip20pt
+\\{help2}({\tt\char`\"Sorry,\]\char`\\setbox\]is\]not\]allowed\]after\]%
+\char`\\halign\]in\]a\]display,\char`\"})\par\noindent\hskip20pt
+({\tt\char`\"or\]between\]\char`\\accent\]%
+and\]an\]accented\]character.\char`\"});
+\ \\{error};\par\noindent\hskip20pt
+{\bf end};
+
+\bugonpage B511, new line inserted after line 3 (1/24/92)
+
+\ninepoint\noindent\hskip20pt
+\\{flushable\_string}: \\{str\_number};\quad
+ $\{\,$string not yet referenced$\,\}$
+
+\bugonpage B512, new line inserted after line 3 of section 1260 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+$\\{flushable\_string}\gets\\{str\_ptr}-1$;
+
+\bugonpage B512, the former line 6 of section 1260 (1/24/92)
+
+\ninepoint\noindent\hskip30pt
+{\bf begin if\/} $\\{cur\_name}=\\{flushable\_string}$ {\bf then}
+\par\noindent\hskip40pt{\bf begin} \\{flush\_string}; \
+ $\\{cur\_name}\gets\\{font\_name}[f]$; \ {\bf end};
+\par\noindent\hskip30pt{\bf if\/} $s>0$ {\bf then}
+
+\bugonpage B512, line 10 from the bottom (9/19/91)
+
+\ninepoint\noindent
+\\{set\_font}:\enspace{\bf begin}
+\\{print}({\tt\char`\"select\]font\]\char`\"}); \
+\\{slow\_print}(\\{font\_name}[\\{chr\_code}]);
+
+\bugonpage B514, line 9 (1/11/92)
+
+\ninepoint\noindent\hskip20pt
+$\\{set\_box\_allowed}\gets\\{false}$; \
+\\{prefixed\_command}; \
+$\\{set\_box\_allowed}\gets\\{true}$;
+
+\bugonpage B515, line 19 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+\\{slow\_print}($s$); \ \\{update\_terminal};
+
+\bugonpage B516, line 2 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} \\{print\_err}({\tt\char`\"\char`\"}); \
+ \\{slow\_print}($s$);
+
+\bugonpage B531, lines 19 and 20 (9/19/91)
+
+\ninepoint\noindent\hskip10pt
+\\{print\_nl}({\tt\char`\"Beginning\]to\]dump\]on\]file\]\char`\"}; \
+\\{slow\_print}(\\{w\_make\_name\_string}(\\{fmt\_file})); \
+\\{flush\_string};\par\noindent\hskip10pt
+\\{print\_nl}({\tt\char`\"\char`\"}); \
+\\{slow\_print}(\\{format\_ident})
+
+\bugonpage B533, line 29 (9/19/91)
+
+\ninepoint\noindent\hskip30pt
+{\bf begin} \\{print\_nl}({\tt\char`\"Transcript\]written\]on\]\char`\"}); \
+\\{slow\_print}(\\{log\_name}); \
+\\{print\_char}({\tt\char`\".\char`\"});
+
+\bugonpage B538, line 13 (9/19/91)
+
+\ninepoint\noindent
+10:\enspace\\{slow\_print}($n$);
+
+\bugonpage B577, left column (12/23/91)
+
+\eightpoint\noindent[Add 798 to the index entries for `system dependencies'.]
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\bugonpage C262, line 15 (3/26/91)
+
+\ninepoint\noindent
+|string base_name, base_version; base_name="plain"; base_version="2.7";|
+
+\bugonpage C271, line 17 from the bottom (3/26/91)
+
+\ninepoint\noindent
+|  currentpen_path shifted (z.t_) withpen penspeck enddef;|
+
+\bugonpage C347, Bront''e entry (1/29/91)
+
+\eightpoint\noindent
+[The accent was clobbered; her name should, of course, be Bront\"e.
+Fix the entries for D\"urer, M\"obius, and Stravinsky in the same way.]
+
+\bugonpage C348, left column (1/11/92)
+
+\eightpoint\indent
+compound statement, $\underline{155}$, 217.
+
+\bugonpage C353, right column (1/11/92)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt numeric}, 55, $\underline{56}$, {\it65}, 88.
+
+\bugonpage C354, miscellaneous entries in both columns (1/11/92)
+
+\eightpoint
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt openwindow}, $\underline{191}$--$\underline{193}$, 220, {\it277},
+ {\it312--313}.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt or}, {\it65}, $\underline{170}$, 210, 237, 288--289.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt pair}, 55, $\underline{56}$, 65.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt path}, 55, $\underline{56}$, 171.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt pen}, 55, $\underline{56}$, {\it65}, 170.
+\par\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt picture}, 55, $\underline{56}$, {\it114}.
+
+\bugonpage C356, right column (1/11/92)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt string}, 55, $\underline{56}$, 69.
+
+\bugonpage C357, right column (1/11/92)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt transform}, 55, $\underline{56}$, 57, 141--143, {\it160}, 266.
+
+% Volume D
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage D2, last line of section 2 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]METAFONT,\]Version\]2.71\char'23}\quad
+$\{\,$printed when \MF\ starts$\,\}$
+
+\bugonpage D102, line 15 from the bottom (11/1/91)
+
+\tenpoint\noindent
+Then
+$\\{eq\_type}(h(x))=\\{tag\_token}$ and $\\{equiv}(h(x))=p$,
+where $p$~is a two-word value
+node with\cutpar
+
+\bugonpage D188, lines 16 and 17 (1/24/92)
+
+\tenpoint\noindent
+errors. Our subroutines also obey the identity $t[a,b]+t[b,a]=a+b$.
+
+\bugonpage D190, new copy before bottom four lines (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{x\_coord}(r)<\\{x\_coord}(\\{pp})$ {\bf then}
+           $\\{x\_coord}(r)\gets\\{x\_coord}(\\{pp})$\par\noindent\hskip10pt
+{\bf else if\/} $\\{x\_coord}(r)>\\{dest\_x}$ {\bf then}
+           $\\{x\_coord}(r)\gets\\{dest\_x}$;\par\noindent\hskip10pt
+{\bf if\/} $\\{left\_x}(r)>\\{x\_coord}(r)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{left\_x}(r)\gets\\{x\_coord}(r)$; \
+{\bf if\/} $\\{right\_x}(\\{pp})>\\{x\_coord}(r)$ {\bf then}
+$\\{right\_x}(\\{pp})\gets\\{x\_coord}(r)$; \ {\bf end};\par\noindent\hskip10pt
+{\bf if\/} $\\{right\_x}(r)<\\{x\_coord}(r)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{right\_x}(r)\gets\\{x\_coord}(r)$; \
+{\bf if\/} $\\{left\_x}(\\{qq})<\\{x\_coord}(r)$ {\bf then}
+$\\{left\_x}(\\{qq})\gets\\{x\_coord}(r)$; \ {\bf end};
+
+\bugonpage D191, new copy before bottom two lines of section 416 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{x\_coord}(s)<\\{x\_coord}(r)$ {\bf then}
+           $\\{x\_coord}(s)\gets\\{x\_coord}(r)$\par\noindent\hskip10pt
+{\bf else if\/} $\\{x\_coord}(s)>\\{dest\_x}$ {\bf then}
+           $\\{x\_coord}(s)\gets\\{dest\_x}$;\par\noindent\hskip10pt
+{\bf if\/} $\\{left\_x}(s)>\\{x\_coord}(s)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{left\_x}(s)\gets\\{x\_coord}(s)$; \
+{\bf if\/} $\\{right\_x}(r)>\\{x\_coord}(s)$ {\bf then}
+$\\{right\_x}(r)\gets\\{x\_coord}(s)$; \ {\bf end};\par\noindent\hskip10pt
+{\bf if\/} $\\{right\_x}(s)<\\{x\_coord}(s)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{right\_x}(s)\gets\\{x\_coord}(s)$; \
+{\bf if\/} $\\{left\_x}(\\{qq})<\\{x\_coord}(s)$ {\bf then}
+$\\{left\_x}(\\{qq})\gets\\{x\_coord}(s)$; \ {\bf end};
+
+\bugonpage D194, lines 4 and 5 (1/24/92)
+
+\tenpoint\noindent[Delete those two lines; I no longer believe that the 
+assertion has been proved (although it might be true).]
+
+\bugonpage D194, lines 7--13 of section 424 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{y\_coord}(r)<\\{y\_coord}(p)$ {\bf then}
+           $\\{y\_coord}(r)\gets\\{y\_coord}(p)$\par\noindent\hskip10pt
+{\bf else if\/} $\\{y\_coord}(r)>\\{dest\_y}$ {\bf then}
+           $\\{y\_coord}(r)\gets\\{dest\_y}$;\par\noindent\hskip10pt
+{\bf if\/} $\\{x\_coord}(p)+\\{y\_coord}(r)>\\{dest\_x}+\\{dest\_y}$
+{\bf then} $\\{y\_coord}(r)\gets\\{dest\_x}+\\{dest\_y}-\\{x\_coord}(p)$;\par
+\noindent\hskip10pt
+{\bf if\/} $\\{left\_y}(r)>\\{y\_coord}(r)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{left\_y}(r)\gets\\{y\_coord}(r)$; \
+{\bf if\/} $\\{right\_y}(p)>\\{y\_coord}(r)$ {\bf then}
+$\\{right\_y}(p)\gets\\{y\_coord}(r)$; \ {\bf end};\par\noindent\hskip10pt
+{\bf if\/} $\\{right\_y}(r)<\\{y\_coord}(r)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{right\_y}(r)\gets\\{y\_coord}(r)$; \
+{\bf if\/} $\\{left\_y}(q)<\\{y\_coord}(r)$ {\bf then}
+$\\{left\_y}(q)\gets\\{y\_coord}(r)$; \ {\bf end};
+
+\bugonpage D194, lines 8--11 from the bottom (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{right\_y}(r)<\\{y\_coord}(r)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{right\_y}(r)\gets\\{y\_coord}(r)$; \
+{\bf if\/} $\\{left\_y}(q)<\\{y\_coord}(r)$ {\bf then}
+$\\{left\_y}(q)\gets\\{y\_coord}(r)$; \ {\bf end};
+
+\bugonpage D195, lines 3--9 of section 425 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{y\_coord}(s)<\\{y\_coord}(r)$ {\bf then}
+           $\\{y\_coord}(s)\gets\\{y\_coord}(r)$\par\noindent\hskip10pt
+{\bf else if\/} $\\{y\_coord}(s)>\\{dest\_y}$ {\bf then}
+           $\\{y\_coord}(s)\gets\\{dest\_y}$;\par\noindent\hskip10pt
+{\bf if\/} $\\{x\_coord}(r)+\\{y\_coord}(s)>\\{dest\_x}+\\{dest\_y}$
+{\bf then} $\\{y\_coord}(s)\gets\\{dest\_x}+\\{dest\_y}-\\{x\_coord}(r)$;\par
+\noindent\hskip10pt
+{\bf if\/} $\\{left\_y}(s)>\\{y\_coord}(s)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{left\_y}(s)\gets\\{y\_coord}(s)$; \
+{\bf if\/} $\\{right\_y}(r)>\\{y\_coord}(s)$ {\bf then}
+$\\{right\_y}(r)\gets\\{y\_coord}(s)$; \ {\bf end};\par\noindent\hskip10pt
+{\bf if\/} $\\{right\_y}(s)<\\{y\_coord}(s)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{right\_y}(s)\gets\\{y\_coord}(s)$; \
+{\bf if\/} $\\{left\_y}(q)<\\{y\_coord}(s)$ {\bf then}
+$\\{left\_y}(q)\gets\\{y\_coord}(s)$; \ {\bf end};
+
+\bugonpage D195, lines 3--7 from the bottom if section 425 (1/24/92)
+
+\ninepoint\noindent\hskip10pt
+{\bf if\/} $\\{right\_y}(s)<\\{y\_coord}(s)$ {\bf then}\par\noindent\hskip20pt
+{\bf begin} $\\{right\_y}(s)\gets\\{y\_coord}(s)$; \
+{\bf if\/} $\\{left\_y}(q)<\\{y\_coord}(s)$ {\bf then}
+$\\{left\_y}(q)\gets\\{y\_coord}(s)$; \ {\bf end};
+
+\bugonpage D289, lines 9 and 10 (11/1/91)
+
+\ninepoint\noindent\hskip20pt
+$p\gets\\{dep\_list}(p)$; \ $r\gets\\{inf\_val}$;\par\noindent\hskip20pt
+{\bf repeat if\/} $\\{value}(\\{info}(p))\ge\\{value}(r)$ {\bf then}\par
+
+\bugonpage D486, line 18 (11/1/91)
+
+\tenpoint\noindent
+The \\{label\_loc}
+and \\{label\_char} arrays have been set up to record all the
+starting addresses; we have\cutpar
+
+% volume E
+\hsize=29pc
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+
+\bye
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.six b/Master/texmf-dist/doc/generic/knuth-errata/errata.six
new file mode 100644
index 00000000000..ad7444d8600
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.six
@@ -0,0 +1,528 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 1990}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting}, Volumes A,~C, and E\null, between 30 September 1989 (when
+the revisions for \TeX\ Version 3.0 and \MF\ Version 2.0 were made) and
+December 31, 1990.
+Corrections made to the softcover version of {\sl The \TeX book\/} are
+the same as corrections to Volume~A\null. Corrections to the softcover
+version of {\sl The \slMF\kern1ptbook\/} are the same as corrections
+to Volume~C\null.  Some of the corrections below have already been made in
+reprintings of the books. Hundreds of changes, too many to list here,
+have been made to Volumes B~and~D because of the upgrades to \TeX\ and
+\MF\null.  Readers who need up-to-date information on the \TeX\ and
+\MF\ programs should refer to the |WEB| source files until new
+printings of Volumes B~and~D are issued. \looseness=-1
+
+% volume A
+
+\bugonpage A99, line 4 from the bottom (2/22/90)
+
+\ninepoint\indent
+to be chosen because there was no feasible
+way to keep total demerits small.
+
+\bugonpage A124, lines 18--21 (9/5/90)
+
+\ninepoint\noindent
+Floating insertions can be accommodated
+as a special case of split insertions, by making each floating topinsert
+start with a small penalty, and by having
+zero as the associated |\floatingpenalty|; non-floating insertions
+like footnotes are accommodated by associating larger penalties with
+split insertions (see Appendix~B).
+
+\bugonpage A137, lines 2 and 3 from the bottom (11/9/90)
+
+{\eightssi
+\rightline{and you shouldn't even be reading this manual,}
+\rightline{which is undoubtedly all English to you.}
+}
+
+\bugonpage A141, line 15 from the bottom (10/18/90)
+
+\tenpoint\noindent
+Thus if you type `|$1\over2$|' (in a text) you get $1\over2$, namely style
+$S$ over style~$S'$;\cutpar
+
+\bugonpage A156, line 2 (11/18/89)
+
+\ninepoint
+Commands like |\mathchardef\alpha="010B| are used in
+Appendix~B to define\cutpar
+
+\bugonpage A165, lines 2--3 (8/13/90)
+
+\ninepoint
+ Type the formula $\bf\bar x^{\rm T}Mx={\rm0}\iff x=0$,
+using as few keystrokes as possible.
+\ (The first `0' is roman, the second is bold. The superscript `T' is roman.)
+
+\bugonpage A171, lines 24--26 (3/13/90)
+
+\ninepoint\noindent
+formula produces a result exactly equivalent to
+`|\left(|\<subformula>|\right)|', when the \<subformula> doesn't end
+with Punct, except that the {delimiters} are forced to
+be of the |\big| size regardless of the height and depth of the subformula.
+
+\bugonpage A193, lines 16--18 (12/2/89)
+
+\ninepoint\noindent
+line if you insert
+`^|\noalign||{|^|\break||}|'
+after the |\cr| for that line. You can prohibit {\sl all\/} breaks
+in an |\eqalignno| if you set ^|\interdisplaylinepenalty||=10000|; or you
+can enclose the whole works in a ^|\vbox|:
+
+\bugonpage A233, bottom 9 lines, and top three on next page (12/2/89)
+
+\danger The |\+| macro in Appendix~B works
+by putting the \<text> for each column that's followed by~|&|
+into an hbox as follows:
+\begindisplay
+|\hbox to |\<column width>|{|\<text>|\hss}|
+\enddisplay
+The ^|\hss| means that the text is normally flush left, and that it can
+extend to the right of its box. Since |\hfill| is ``more infinite'' than
+|\hss| in its ability to stretch, it has the effect of right-justifying or
+centering as stated above. Note that |\hfill| doesn't shrink, but |\hss|
+does; if the text doesn't fit in its column, it will stick out at the right.
+You could cancel the shrinkability of |\hss| by adding ^|\hfilneg|; then
+an oversize text would produce an overfull box.
+You could also center some text by putting `|\hss|' before it and just
+`|&|' after it; in that case the text would be allowed to extend to the
+left and right of its column.
+ The last column of a |\+|~line (i.e., the column entry that is
+followed by |\cr|) is treated differently: The
+\<text> is simply put into an hbox with its natural~width.\looseness=-1
+
+\bugonpage A254, line 5 from the bottom (10/5/89)
+
+\ninepoint\noindent
+|\vsize| hasn't changed, and if all insertions have been
+held in place, the same page break\cutpar
+
+\bugonpage A286, lines 30--32 (3/13/90)
+
+\ninepoint\noindent
+reading and expanding this \cstok{par}
+token, \TeX\ will see the \<vertical command> token again. \ (The current
+meaning of the control sequence ^|\par| will be used; \cstok{par} might no
+longer stand for \TeX's |\par| primitive.)
+
+\bugonpage A290, lines 12--13 (3/24/90)
+
+\ninepoint\noindent
+simply a single Ord atom without subscripts or superscripts,
+or an Acc whose nucleus is an Ord, the
+enclosing braces are effectively removed.
+
+\bugonpage A317, line 17 (5/17/90)
+
+\ninepoint
+|\pretolerance=9999 \tolerance=9999 \parindent=0pt|
+
+\bugonpage A321, lines 16--17 (8/13/90)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss18.6.\enspace}\ignorespaces
+|$\bf\bar x^{\rm T}Mx={\rm0}\iff x=0$|.  \ (If you typed a space between
+|\rm| and~|0|, you wasted a keystroke; but don't feel guilty about it.)
+
+\bugonpage A340, nonblank line 11 (3/13/90)
+
+\tenpoint\noindent
+|\topglue 1in % This makes an inch of blank space (1in=2.54cm).|
+
+\bugonpage A342, line 6 (3/13/90)
+
+\tenpoint\noindent
+|\topglue| but not |\hglue|. It does not
+illustrate |\raggedright| setting of para-\cutpar
+
+\bugonpage A346, lines 20--21 (12/3/89)
+
+\ninepoint\noindent
+streams used by ^|\read| and ^|\write|, to math
+^{families} used by ^|\fam|, to sets of hyphenation rules used by
+^|\language|, and to insertions (which require
+^|\box|, ^|\count|, ^|\dimen|, and ^|\skip| registers all having the
+same number).
+
+\bugonpage A346, line 20 from the bottom (12/3/89)
+
+\ninepoint\noindent
+manent value. These macros use registers
+|\count10| through |\count20| to hold the\cutpar
+
+\bugonpage A346, lines 8--13 from the bottom (12/3/89)
+
+\ninepoint\noindent
+number was allocated. The inside story of how allocation is actually performed
+should be irrelevant when the allocation macros are used at a higher level;
+you mustn't assume that |plain.tex| really does allocation in any
+particular way.
+\beginlines
+|\count10=22 % this counter allocates \count registers 23, 24, 25, ...|
+\endgroup
+
+\bugonpage A347, lines 2--5 (12/3/89)
+
+\ninepoint{\parindent=0pt
+|\count19=0  % this counter allocates language codes 1, 2, 3, ...|\parbreak
+|\count20=255 % this counter allocates insertions 254, 253, 252, ...|\parbreak
+|\countdef\insc@unt=20 % nickname for the insertion counter|\parbreak
+|\countdef\allocationnumber=21 % the most recent allocation|\parbreak
+|\countdef|^|\m@ne||=22 \m@ne=-1 % a handy constant|\par}
+
+\bugonpage A347, new line after former line 17 (12/3/89)
+
+\ninepoint\noindent
+|\outer\def|^|\newlanguage||{\alloc@9\language\chardef\@cclvi}|
+
+\bugonpage A352, new line before line 6 from the bottom (3/13/90)
+
+\ninepoint\noindent
+|\def\topglue{\nointerlineskip \vglue-\topskip \vglue} % for top of page|
+
+\bugonpage A355, line 8 from the bottom (12/3/89)
+
+\ninepoint\noindent
+|  \noindent{\bf#1.\enspace}{\sl#2\par}%|
+
+\bugonpage A363, lines 8--9 from the bottom (12/8/89)
+
+{\ninepoint\parindent=0pt
+|  \if@mid \dimen@=\ht0 \advance\dimen@ by\dp\z@ |%
+ |\advance\dimen@ by12\p@|\parbreak%
+|    \advance\dimen@ by\pagetotal \advance\dimen@ by-\pageshrink|
+\par}
+
+\bugonpage A375, line 27 (10/30/89)
+
+\ninepoint\noindent
+depending on whether or not |\t|~contains
+an asterisk. \ (Do you see why?) \ And here's\cutpar
+
+\bugonpage A393, lines 3--5 from the bottom (12/3/89)
+
+\ninepoint
+|\hskip-.17em plus-3em minus.11em|\par
+|\vadjust{}\penalty10000|\par
+|\leaders\copy\dbox\hskip3.3\wd\dbox plus1fil minus.3\wd\dbox|
+
+\bugonpage A444, line 4 (3/13/90)
+
+\ninepoint\noindent
+Shift box~$x$ down by ${1\over2}\bigl(h(x)-d(x)\bigr)
+-a$, where $a=\sigma_{22}$, so that the operator character\cutpar
+
+\bugonpage A450, line 8 (12/3/89)
+
+\def\\#1{$_{\kern\scriptspace#1}$}
+\ninepoint\indent
+{\qquad\tt\\0h\\0e\\0n\\5a\\0t\\0 \\1n\\0a\\0 \\0n\\2a\\0t\\0
+  \\1t\\0i\\0o\\0 \\2i\\0o\\0 \\0o\\2n\\0}
+
+\bugonpage A450, line 14 (12/3/89)
+
+\ninepoint
+{\tt.\\0h\\0y$_3$p\\0h\\0e\\2n\\5a\\4t\\2i\\0o\\2n\\0.}
+
+\bugonpage A450, lines 19 and 20 (12/3/89)
+
+\ninepoint\vskip-10pt
+\begindisplay
+\tt\\0o\\2n\\0
+\\0o\\0n\\1c\\0
+\\1c\\0a\\0
+\\1n\\0a\\0
+\\0n\\2a\\0t\\0
+\\1t\\0i\\0o\\0
+\\2i\\0o\\0
+\\0o\\2n\\0
+\enddisplay
+and this yields `{\tt\\0c\\0o\\2n\\1c\\0a\\0t\\0e\\1n\\2a\\1t\\2i\\0o\\2n\\0}',
+i.e., `|con-cate-na-tion|'.
+
+\bugonpage A455, last lines before the quotes (11/30/89)
+
+\ninepoint\noindent
+sit yourself (even in restricted horizontal mode) by saying
+^|\setlanguage|\<number>;\break
+ this changes the current language but it
+does not change |\language|. Each what-\break
+sit records the current
+|\lefthyphenmin| and |\righthyphenmin|.
+
+\bugonpage A467, right column (12/3/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\hfilneg|, 72, 100, 233, 283, 285, 290, 397.
+
+\bugonpage A468, right column (12/2/89)
+
+\eightpoint
+|\interdisplaylinepenalty|, {\it193}, 349, 362.
+
+\bugonpage A469, left column (12/3/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\language| (hyphenation method), 273, 346, $\underline{455}$.
+
+\bugonpage A469, right column (10/30/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\lefthyphenmin|, 273, {\it364}, $\underline{454}$, 455.
+
+\bugonpage A472, left column (12/3/89)
+
+\eightpoint
+|\newlanguage|, 346, $\underline{347}$.
+
+\bugonpage A476, left column (10/30/89)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+|\righthyphenmin|, 273, {\it364}, $\underline{454}$, 455.
+
+\bugonpage A479, new entry (3/13/90)
+
+\eightpoint
+|\topglue|, {\it340}, $\underline{352}$.
+
+\bugonpage A480, right column (3/13/90)
+
+\eightpoint
+|\vglue|, $\underline{352}$, {\it408}.
+
+\bugonpage A483, the Providence lines (10/8/89)
+
+\noindent[Change the first one to
+\begintt
+Providence RI 02940\kern.05em-9506, USA.
+\endtt
+Then the second one will be
+\begindisplay
+Providence RI 02940\kern.05em-9506, USA.
+\enddisplay
+The second line will also appear on page C361.]
+
+% volume B
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\bugonpage C11, replacement for second quotation at bottom of page (9/27/90)
+
+\begingroup
+  \eightpoint \let\tt=\ninett
+  \baselineskip 10pt
+  \parfillskip \z@
+  \interlinepenalty 10000
+  \leftskip \z@ plus 40pc minus \parindent
+  \let\rm=\eightss \let\sl=\eightssi
+  \everypar{\sl}
+  \def\par{\ifhmode\/\endgraf\fi}\obeylines
+To anyone who has lived in a modern American city (except Boston)
+at least one of the underlying ideas of ^{Descartes}' analytic geometry
+will seem ridiculously evident. Yet, as remarked,
+it took mathematicians all of two thousand years
+to arrive at this simple thing.
+\author ERIC TEMPLE ^{BELL}, {\sl Mathematics: Queen and Servant of %
+ Science\/} (1951) % p123
+
+\endgroup
+
+\bugonpage C220, top line (3/13/90)
+
+\ninepoint\noindent
+modes you get into by hitting
+`|S|', `|R|', or `|Q|', respectively, in response to error messages\cutpar
+
+\bugonpage C252, line 16 (3/13/90)
+
+\ninepoint\indent
+| for i:=1 upto n_windows: display blankpicture inwindow i; endfor|
+
+\bugonpage C262, lines 19--21 (11/9/90)
+
+\ninepoint\noindent
+for commonly occurring idioms.
+For example, `{\bf stop} |"hello"|' displays `|hello|' on the terminal and waits
+until \<return> is typed.
+\beginlines
+|def |^|upto|| = step 1 until enddef;  def |^|downto|| = step -1 until enddef;|
+\endgroup
+
+\bugonpage C264, lines 4--6 from the bottom (3/24/90)
+
+\ninepoint\noindent
+|vardef |^|counterclockwise|| primary c =|\par\noindent
+| if turningcheck>0:|\par\noindent
+|  interim |^|autorounding||:=0;|\par\noindent
+|  if |^|turningnumber|| c <= 0: reverse fi fi c enddef;|
+
+\bugonpage C306, line 6 (3/13/90)
+
+\ninepoint\noindent
+| ligtable "'": "'" =: oct"042",                         % close quotes|
+
+\bugonpage C309, second line from bottom (11/18/89)
+
+\ninepoint\noindent
+| define_whole_vertical_blacker_pixels(vair,slab,| $\cdots$ |);|
+
+\bugonpage C315, line 9 from the bottom (1/2/90)
+
+\ninepoint\noindent
+units of printer's points):
+
+\bugonpage C329, line 25 (12/29/90)
+
+\ninepoint\noindent
+which can be used to specify a nonstandard file area
+or directory name for the gray\cutpar
+
+\bugonpage C337, line 4 from the bottom (1/7/90)
+
+\ninepoint\noindent
+|\def\startfont{\font\testfont=\fontname \spaceskip=0pt|
+
+\bugonpage C347, left column (9/27/90)
+
+\eightpoint\noindent
+Bell, Eric Temple, 11.
+
+\bugonpage C349, left column (9/27/90)
+
+\eightpoint\noindent
+Descartes, Ren\'e, 6, 11, 19.
+
+\bugonpage C356, right column (9/27/90)
+
+\eightpoint\noindent
+[remove the entry for Rex Stout.]
+
+\bugonpage C358, right column (9/27/90)
+
+\eightpoint\noindent
+[remove the entry for Nero Wolfe.]
+
+% Volume D
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+% volume E
+\hsize=29pc
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+\bugonpage Exiii, replacement for last four lines (4/30/90)
+
+\textindent{\bull}``AMS Euler---A new typeface for mathematics''
+ by Donald~E. Knuth
+and Hermann Zapf, {\sl Scholarly Publishing\/ \bf21} (1989), 131--157.
+\ {\it The story of a design project that helps bridge the gulf between
+mathematics and art.}
+
+\smallskip
+\textindent{\bull}``Meta-Marks:
+ Preliminary studies for a Pandora's Box of shapes''
+by Neenie Billawala, Stanford Computer Science report 1259 (Stanford,
+California, July 1989), 132~pp.
+\ {\it Lavishly illus\-trated studies in parameter variation,
+leading to the design of a new typeface called Pandora.}
+
+
+
+\bugonpage E325, line 13 (3/13/90)
+
+\ninepoint\noindent
+{\bf if} \\{serifs}: $x_{3r}=\max(x_{1r},{\rm hround}(x_1+.5\\{dot\_diam}
+ -.2\\{jut})-.5\\{tiny})$\par\noindent
+{\bf else}: $x_3=x_1-.5$ {\bf fi};
+
+\bugonpage E483, line 4 (3/13/90)
+
+\ninepoint
+\rightline{\% Character codes \oct{000}--\oct{100} and \oct{133}--\oct{177}
+ are generated.}
+
+\bugonpage E544, line 5 (3/13/90)
+
+\ninepoint\noindent
+\hskip 3em\vdots\hskip2em\raise2pt\hbox{(the rest of the
+ program for `$\gamma$' in |greekl| comes here)}
+
+\bugonpage E557, line 9 (3/13/90)
+
+\ninepoint
+\rightline{\sl`Nevermore---Ah nevermore.'\thinspace''}
+
+\bugonpage E558, line 21 (3/13/90)
+
+\eightpoint\noindent
+|Clasp a rare and radiant maiden whom the angels name Lenore."|
+
+\bugonpage E570, lines 27--28 look better with proper skewchars (3/13/90)
+
+\begingroup
+\tenpoint\bf
+\textfont0=\tenbf \scriptfont0=\sevenbf
+\font\boldi=cmmib10 \font\boldsy=cmbsy10
+\skewchar\boldi='177 \skewchar\boldsy='60
+\textfont1=\boldi
+\textfont2=\boldsy
+\noindent Here's some bold 10-point math:
+${\hat A}^\Gamma_0
++{\check B}^\Delta_1
+-{\tilde C}^\Theta_2
+\times{\acute D}^\Lambda_3
+/{\grave E}^\Xi_4
+\oplus{\dot F}^\Pi_5
+\ominus{\ddot G}^\Sigma_6
+\otimes{\breve H}^\Phi_7
+\oslash{\bar I}^\Psi_8
+\odot{\vec J}^{\,\Omega}_9$.
+\endgroup
+
+\bye
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.ten b/Master/texmf-dist/doc/generic/knuth-errata/errata.ten
new file mode 100644
index 00000000000..9efa2a3e503
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.ten
@@ -0,0 +1,1289 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\def\curl{\mathop{\rm curl}}
+\def\cycle{{\rm cycle}}\indent
+\def\dashto{\mathrel{\hbox{-\thinspace-\kern-.05em}}}
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting, 2000}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all substantial corrections made to {\sl Computers
+\& Typesetting\/} from the mid-1990s until the first ``Millennium edition'' was
+published at the end of the year 2000.
+Corrections made to the softcover version of {\sl The \TeX book\/} are
+the same as corrections to Volume~A\null. Corrections to the softcover
+version of {\sl The \slMF\kern1ptbook\/} are the same as corrections
+to Volume~C\null. Changes to the mini-indexes
+and master indexes of Volumes B, D, and~E are not shown here unless they are
+not obviously derivable from what has been shown.
+\looseness=-1
+
+% volume A
+
+\bugonpage A3, line 14 {(in certain printings only)} (9/6/00)
+
+\tenpoint\noindent
+that
+looks like {\tt\char'15} or {\tt\char'23}.
+
+\bugonpage A8, lines 14 and 15 (9/6/00)
+
+\tenpoint\noindent
+that is not to be ignored. Notice that |\|\] is a control
+sequence of the second kind, namely a control symbol, since there is a
+single nonletter (\]) following\cutpar
+
+\bugonpage A43, line $-17$ (8/4/98)
+
+\tenpoint\noindent
+into your manuscript, if the |b|-key on your keyboard is broken. \
+(An optional\cutpar
+
+\bugonpage A88, lines 14, 16, 18, and 21 (8/12/00)
+
+\tenpoint\noindent
+[Insert two blank spaces between `{\tt blank space}' and `{\tt\char`\}}']
+
+\bugonpage A96, lines 9 and 10 (8/6/98)
+
+\ninepoint\indent
+Before 1998, some ^{German} words changed their spelling
+when split between lines. For example, `backen' became `bak-ken'
+and `Bettuch' sometimes became `Bett-\cutpar
+
+\bugonpage A107, line 2 (8/5/98)
+
+\ninepoint
+\line{\indent\spaceskip=.4em minus.35em
+ually, you might be tempted to set
+|\tolerance=10000|; this allows arbitrarily bad}
+
+\bugonpage A115, line $-19$ (8/5/98)
+
+\ninepoint\noindent
+If there's no room for such an insertion on this page, \TeX\
+will insert it at the top of\cutpar
+
+\bugonpage A119, line 15 (8/5/98)
+
+\ninepoint\noindent
+of\/ |\dimen3|, assuming that |\dimen3| is positive.
+
+\bugonpage A182, middle line of the displayed commutative diagram (12/3/99)
+
+\ninepoint
+\def\mapright#1{\smash{
+    \mathop{\longrightarrow}\limits^{#1}}}
+$$\matrix{
+  0&\mapright{}&{\cal O}_C&\mapright\pi&
+    \pi_*{\cal O}_D&\mapright\delta&
+    R^1f_*{\cal O}_V(-D)&\mapright{}&0\cr}$$
+
+\bugonpage A233, line $-2$ (8/5/98)
+
+\ninepoint\noindent
+could avoid this by adding |\hskip| |0pt| |minus-1fil|; then
+an oversize text would\cutpar
+
+\bugonpage A277, line 1 (8/5/98)
+
+\ninepoint\indent
+\<code assignment>\is\<codename>\<8-bit number>\<equals>\<number>
+
+\bugonpage A277, line $-11$ (8/5/98)
+
+\ninepoint\noindent
+[Move this line, which defines \<at clause>, up to the top of the page.]
+
+\bugonpage A289, line 24 (2/3/97)
+
+\ninepoint\indent
+\<math field>\is\<filler>\<math symbol>\alt\<filler>|{|\<math mode material>|}|
+
+\bugonpage A309, line 3 (8/12/97)
+
+\ninepoint
+\ansno8.4:
+|$|$_{3}$ |x|$_{11}$ |^|$_7$ |2|$_{12}$ |$|$_{3}$ |~|$_{13}$ \]$_{10}$
+\cstok{TeX} |b|$_{11}$ |v|$_{11}$ \]$_{10}$. The final space comes from
+the\cutpar
+
+\bugonpage A313, line 24 (9/19/00)
+
+\ninepoint\noindent
+stands for `|\par\vfill...|', so the next three commands are
+
+\bugonpage A313, line 27 (9/19/00)
+
+\ninepoint\indent
+|{vertical mode: \par}|
+
+\bugonpage A318, lines 12 and 13 (8/5/98)
+
+\ninepoint\noindent\hbox to\parindent{\hfil\bf15.8.\enspace}%
+|\advance\dimen2 by\ifnum\dimen2<0 -\fi.5\dimen3|\parbreak
+|\divide\dimen2 by\dimen3 \multiply\dimen2 by\dimen3|
+
+\bugonpage A325, line 22 (12/3/99)
+
+\ninepoint
+|  0&\mapright{}&{\cal O}_C&\mapright\pi&|
+
+\bugonpage A337, line 3 from the bottom (9/6/00)
+
+\rightline{\eightss DONALD E. KNUTH, {\eightssi The \TeX book\/} (1984)}
+
+\bugonpage A348, lines 14--16 (8/6/98)
+
+\ninepoint\noindent
+|   \def\@if#1{true}{\let#1=\iftrue}%|\par\noindent
+|  \expandafter\expandafter\expandafter|\par\noindent
+|   \def\@if#1{false}{\let#1=\iffalse}%|\par\noindent
+
+\bugonpage A356, line 21 (8/6/98)
+
+\ninepoint\noindent
+|\def\AA{\leavevmode\setbox0=\hbox{!}\dimen@=\ht0 \advance\dimen@ by-1ex|
+
+\bugonpage A356, lines 9--21 from the bottom (8/6/98)
+
+\ninepoint
+{\parindent=0pt
+|\def\S{\mathhexbox278} \def\P{\mathhexbox27B} \def\Orb{\mathhexbox20D}|\par
+\smallskip
+|\def\oalign#1{\leavevmode\vtop{\baselineskip0pt \lineskip.25ex|\par
+|  \ialign{##\crcr#1\crcr}}} \def\o@lign{\lineskiplimit=0pt \oalign}|\par
+|\def\ooalign{\lineskiplimit=-\maxdimen \oalign} % chars over each other|\par
+|{\catcode`p=12 \catcode`t=12 \gdef\\#1pt{#1}} \let\getf@ctor=\\|\par
+|\def\sh@ft#1{\dimen@=#1 \kern\expandafter\getf@ctor\the\fontdimen1\font|\par
+|  \dimen@} % kern by #1 times the current slant|\par
+|\def\d#1{{\o@lign{\relax#1\crcr\hidewidth\sh@ft{-1ex}.\hidewidth}}}|\par
+|\def\b#1{{\o@lign{\relax#1\crcr\hidewidth\sh@ft{-3ex}%|\par
+|    \vbox to.2ex{\hbox{\char'26}\vss}\hidewidth}}}|\par
+|\def\c#1{{\setbox0=\hbox{#1}\ifdim\ht0=1ex \accent'30 #1%|\par
+|  \else\ooalign{\unhbox0\crcr\hidewidth\char'30\hidewidth}\fi}}|\par
+|\def\copyright{{\ooalign{\hfil\raise.07ex\hbox{c}\hfil\crcr\Orb}}}|\par
+}
+
+\bugonpage A364, line 9 (8/9/98)
+
+\ninepoint\noindent
+|\def\makefootline{\baselineskip=24pt \lineskiplimit=0pt|\par\noindent
+|    \line{\the\footline}}|
+
+
+\bugonpage A364, line 4 from the bottom (8/6/98)
+
+\ninepoint\noindent
+|\def\fmtversion{3.1415926} % identifies the current format|
+
+\bugonpage A447, bottom line (6/3/98)
+
+\rightline{\eightss--- JOHN SMITH, {\eightssi The Printer's Grammar\/}\enspace
+ (1755)}
+
+\bugonpage A450, lines 11--13 (4/12/98)
+
+\def\\#1{$_{\kern\scriptspace#1}$}%
+\tenpoint\noindent
+between `|e|' and `|n|' there are five relevant values
+in this case (2~from {\tt\\0h\\0e\\2n\\0},
+0~from {\tt\\0h\\0e\\0n\\0a\\4},
+0~from {\tt\\0h\\0e\\0n\\5a\\0t\\0},
+1~from {\tt\\1n\\0a\\0},
+and 0~from {\tt\\0n\\2a\\0t\\0}); the maximum of these is~2.
+The result of all the maximizations is
+
+\bugonpage A453, line 6 (8/5/98)
+
+\ninepoint\noindent
+tion dictionary, except that plain \TeX\ blocks hyphens after the
+very first letter or be-\cutpar
+
+\bugonpage A458, left column (9/6/00)
+
+\eightpoint
+\leavevmode{\tt\rlap<\char`\_}, 45, 135, 368--369; {\sl see also\/} |\le|.\par
+\leavevmode{\tt\rlap/=}, 45, 135, 368--369; {\sl see also\/} |\ne|.\par
+\leavevmode{\tt\rlap>\char`\_}, 45, 135, 368--369; {\sl see also\/} |\ge|.
+
+\bugonpage A458, right column (7/5/99)
+
+\eightpoint
+{\tt\char'13} and {\tt\char'14}, 135, 343, 368--369, 429;\par
+al-Khw\^arizm\^\i, abu `Abd All\^ah Mu\d{h}ammad ibn M\^us\^a, 53.
+
+\bugonpage A464, right column (8/6/98)
+
+\eightpoint
+\newbox\astbox \setbox\astbox=\hbox to0pt{\hss\lower1pt\hbox{*}}
+\def\prim#1{\par\indent\copy\astbox{\tt\char`\\#1}}
+\prim{edef}, {\it215--216}, 275, {\it328}, {\it373--374}.
+
+\bugonpage A466, right column (8/8/98)
+
+\eightpoint
+|\getfactor|, {\it356}, $\underline{375}$, {\it398}.
+
+\bugonpage A467, right column (8/5/98)
+
+\eightpoint
+\prim{hfilneg}, 72, 100, 283, 285, 290, 397.
+
+\bugonpage A469, left column (8/5/98)
+
+\eightpoint
+italic type, 13--14, 100, 127, 165, 409, 428, 430.
+
+\bugonpage A469--A477, passim (5/13/98)
+
+\eightpoint\noindent
+Add page 272 to the index entries for |\lastskip|, |\pagedepth|,
+|\pagefilllstretch|,\hfil\break |\pagefillstretch|, |\pagefilstretch|,
+|\pagegoal|, |\pageshrink|, |\pagestretch|, |\pagetotal|,\hfil\break
+|\parshape|, |\prevdepth|, and |\spacefactor|.\par
+\smallskip\noindent Also change `369' to `370' in the index entries for
+|\lbrack|, |\lq|, |\rbrack|, |\rq|, |\sb|, and |\sp|.\par
+\smallskip\noindent Also change `Luckombe, Philip' to `Smith, John'.\par
+
+\bugonpage A472, right column (8/6/98)
+
+\eightpoint
+\prim{noexpand}, $\underline{209}$, $\underline{213}$, 215, 216,
+ {\it377}, {\it424}.
+
+\bugonpage A473, left column (8/6/98)
+
+\eightpoint
+|\Orb| ( \Orb\ ), $\underline{356}$.
+
+% volume B
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Bix, line 16 (1/16/00)
+
+\tenpoint\textindent{\bull}``Word hy-phen-a-tion by com-put-er''
+by Franklin Mark Liang, Stan-\cutpar
+
+\bugonpage Bxiv, line 13 (4/19/96)
+
+\tenpoint\noindent preprocessor converts these into numeric constants that are
+256 or more. This\cutpar
+
+\bugonpage Bxiv, line $-1$ (4/19/96)
+
+\ninepoint\noindent This file contains one line per string, starting with
+string number 256, then number 257,\cutpar
+
+\bugonpage Bxv, lines 10 and 11 (4/19/96)
+
+\ninepoint\noindent
+In this case, occurrences of |""| in the |WEB| program will be replaced by
+256; occurrences of |"This longer string"| will be replaced by 257.
+The symbol |@$| stands for the numeric\cutpar
+
+\hsize=35pc
+\bugonpage B2, line $-10$ (3/8/95)
+
+\def\RQ/{{\char'23}} % right quote in a string
+\ninepoint\noindent\quad
+{\bf define} $\\{banner}\equiv\hbox{\tt\RQ/This\]is\]TeX,\]%
+   Version\]3.14159\RQ/}$\quad$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B169, line 13 (9/22/95)
+
+\tenpoint\noindent
+something in a ``muskip'' register, or to one of the
+three parameters \hbox{\tt\char`\\thinmuskip},
+\hbox{\tt\char`\\medmuskip},\cutpar
+
+\bugonpage B221, line 9 (3/4/95)
+
+\ninepoint\noindent
+\quad{\bf define} $\\{non\_address}=0$\quad
+$\{\,$a spurious \\{bchar\_label}$\,\}$
+
+\bugonpage B221, line 17 (3/4/95)
+
+\ninepoint\noindent
+\\{font\_params}: {\bf array}[\\{internal\_font\_number}] {\bf of}
+ \\{font\_index};\quad$\{\,$how many font parameters are present$\,\}$
+
+\bugonpage B256, insert new line 12 before the bottom (3/7/95)
+
+\ninepoint\noindent\qquad
+\\{glue\_temp}: \\{real};\quad $\{\,$glue value before rounding$\,\}$
+
+\bugonpage B258, line 11 before the bottom becomes four lines (3/7/95)
+
+\ninepoint\noindent
+{\tenbf 625.}\quad{\bf define} $\\{billion}\equiv
+   \\{float\_constant}(1000000000)$\par\noindent
+{\bf define} $\\{vet\_glue}(\hbox{\tt\char`\#})\equiv
+  \\{glue\_temp}\gets\hbox{\tt\char`\#}$;\par\noindent
+\qquad{\bf if\/} $\\{glue\_temp}>\\{billion}$
+  {\bf then} $\\{glue\_temp}\gets\\{billion}$\par\noindent
+\qquad{\bf else if\/} $\\{glue\_temp}<-\\{billion}$
+  {\bf then} $\\{glue\_temp}\gets-\\{billion}$\smallskip\noindent
+$\langle\,$Move right or output leaders{\sevenrm\kern.5em625}$\,\rangle\equiv$
+
+\bugonpage B258, lines 3--6 from the bottom (3/7/95)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{vet\_glue}(\\{float}(\\{glue\_set}
+         (\\{this\_box}))*\\{stretch}(g))$;\par\noindent
+\qquad\qquad$\\{rule\_wd}\gets\\{rule\_wd}+
+             \\{round}(\\{glue\_temp})$;\par\noindent
+\qquad\qquad{\bf end};\par\noindent
+\qquad\quad{\bf end}\par\noindent
+\qquad{\bf else if\/} $\\{shrink\_order}(g)=\\{g\_order}$
+             {\bf then}\par\noindent
+\qquad\quad{\bf begin} $\\{vet\_glue}(\\{float}(\\{glue\_set}
+                (\\{this\_box}))*\\{shrink}(g))$;\par\noindent
+\qquad\quad$\\{rule\_wd}\gets\\{rule\_wd}-\\{round}(\\{glue\_temp})$;
+
+\bugonpage B260, line 13 from the bottom (6/26/93)
+
+\ninepoint
+\noindent\hskip10pt
+$\\{doing\_leaders}\gets\\{outer\_doing\_leaders}$; \
+$\\{dvi\_v}\gets\\{save\_v}$; \
+$\\{dvi\_h}\gets\\{save\_h}$; \
+$\\{cur\_v}\gets\\{base\_line}$;
+
+\bugonpage B261, insert new line after line 7 (3/7/95)
+
+\ninepoint\noindent\qquad
+\\{glue\_temp}: \\{real};\quad $\{\,$glue value before rounding$\,\}$
+
+\bugonpage B262, lines 3--6 from the bottom (3/7/95)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{vet\_glue}(\\{float}(\\{glue\_set}
+         (\\{this\_box}))*\\{stretch}(g))$;\par\noindent
+\qquad\qquad$\\{rule\_ht}\gets\\{rule\_ht}+
+             \\{round}(\\{glue\_temp})$;\par\noindent
+\qquad\qquad{\bf end};\par\noindent
+\qquad\quad{\bf end}\par\noindent
+\qquad{\bf else if\/} $\\{shrink\_order}(g)=\\{g\_order}$
+             {\bf then}\par\noindent
+\qquad\quad{\bf begin} $\\{vet\_glue}(\\{float}(\\{glue\_set}
+                (\\{this\_box}))*\\{shrink}(g))$;\par\noindent
+\qquad\quad$\\{rule\_ht}\gets\\{rule\_ht}-\\{round}(\\{glue\_temp})$;
+
+\bugonpage B264, line 22 (6/26/93)
+
+\ninepoint
+\noindent\hskip10pt
+$\\{doing\_leaders}\gets\\{outer\_doing\_leaders}$; \
+$\\{dvi\_v}\gets\\{save\_v}$; \
+$\\{dvi\_h}\gets\\{save\_h}$; \
+$\\{cur\_h}\gets\\{left\_edge}$;
+
+\bugonpage B297, line 11 (3/7/95)
+
+\ninepoint\noindent
+\qquad  $\\{width}(p)\gets\\{mu\_mult}(\\{width}(p))$; \
+ $\\{subtype}(p)\gets\\{explicit}$;
+
+\bugonpage B309, line 7 (9/22/95)
+
+\ninepoint\noindent
+\qquad {\bf if} $\\{cur\_style}<\\{text\_style}$ {\bf then}
+ \quad$\{\,$display style$\,\}$
+
+\bugonpage B356, line $-5$ (3/4/95)
+
+\tenpoint\noindent
+$\\{hang\_after}=1$, and $\\{hang\_indent}=0$.
+Note that if $\\{hang\_indent}=0$, the value of $\\{hang\_after}$ is\cutpar
+
+\bugonpage B388, bottom line (3/4/95)
+
+\ninepoint\noindent
+\quad {\bf if\/} $\\{bchar\_label}[\\{hf}]\ne\\{non\_address}$ {\bf then}\quad
+ $\{\,$put left boundary at beginning of new line$\,\}$
+
+\bugonpage B406, line 10 (5/1/98)
+
+\ninepoint\noindent
+\qquad$q\gets p$;\quad$\{\,$now node $q$ represents $p_1\ldots p_{l-1}\,\}$
+
+\bugonpage B503, line 12 (3/4/95)
+
+\tenpoint\noindent
+of the following procedure. (Exception: The tabskip
+glue isn't trapped while preambles are being scanned.)
+
+\bugonpage B529, line 12 (3/4/95)
+
+\ninepoint\noindent\quad
+\\{undump}(0)($\\{fmem\_ptr}-1$)(\\{bchar\_label}[$k$]);\par\noindent\quad
+\\{undump}(\\{min\_quarterword})(\\{non\_char})(\\{font\_bchar}[$k$]);
+
+\bugonpage B531, line 2 (11/23/98)
+
+\tenpoint\noindent
+from appearing again.
+
+\bugonpage B531, line 14 (11/23/98)
+
+\ninepoint\noindent
+\quad \\{print\_int}(\\{year}); \ \\{print\_char}(|"."|); \
+     \\{print\_int}(\\{month}); \ \\{print\_char}(|"."|); \
+     \\{print\_int}(\\{day});
+
+\bugonpage B534, insert new material between lines $-16$ and $-15$ (3/20/95)
+
+\ninepoint\noindent
+\quad {\bf while} $\\{input\_ptr}>0$ {\bf do}\par\noindent
+\qquad {\bf if\/} $\\{state}=\\{token\_list}$ {\bf then} \\{end\_token\_list}
+  {\bf else} \\{end\_file\_reading};
+
+\bugonpage B534, line $-2$ (3/20/95)
+
+\ninepoint\noindent
+\qquad $\\{temp\_ptr}\gets\\{cond\_ptr}$; \
+  $\\{cond\_ptr}\gets\\{link}(\\{cond\_ptr})$; \
+  $\\{free\_node}(\\{temp\_ptr},\\{if\_node\_size})$;
+
+\bugonpage B535, line 9 (3/20/95)
+
+\ninepoint\noindent
+\qquad {\bf begin init for} $c\gets\\{top\_mark\_code}$ {\bf to}
+        \\{split\_bot\_mark\_code} {\bf do}\par\noindent
+\qquad\qquad {\bf if\/} $\\{cur\_mark}[c]\ne\\{null}$  {\bf then}
+        $\\{delete\_token\_ref}(\\{cur\_mark}[c])$;\par\noindent
+\qquad\quad \\{store\_fmt\_file}; \ {\bf return}; \ {\bf tini}
+
+\bugonpage B581, Zabala entry (8/19/00)
+
+\eightpoint\noindent
+Zabala Salelles, Ignacio Andr\'es:\quad 2.
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\bugonpage C17, lines 12 and 13 (9/6/00)
+
+\tenpoint
+{\bf draw} $z_4\{\curl0\}\to z_2\{z_3-z_4\}\to\{\curl0\}\,z_3$;\par
+{\bf draw} $z_4\{\curl2\}\to z_2\{z_3-z_4\}\to\{\curl2\}\,z_3$
+
+\bugonpage C23, line $-7$ (8/5/98)
+
+\ninepoint\indent
+$x_1=ss=w-x_5$;\quad$y_3-y_1=\\{ygap}$
+
+\bugonpage C69, line 17 (9/6/00)
+
+\ninepoint\noindent
+|"abra"|, while
+$p_1$ is `$(0,0)\to(3,3)$' and $p_2$ is `$(0,0)\to(3,3)\to\cycle$'.
+
+\bugonpage C94, line $-11$ (3/4/95)
+
+\ninepoint\noindent
+put
+are assumed to have square pixels. But if, for
+example, the {\bf mode\_def} sets\cutpar
+
+\bugonpage C107, line 15 (3/4/95)
+
+\ninepoint
+{\bf labels}$(1a,1b,2a,2b,3a,3b,4a,4b,\,${\bf range} 1 {\bf thru} 36);
+ \ {\bf endchar\/};
+
+\bugonpage C123, lines 21 and 22 (12/19/95)
+
+\chardef\circc=34 % rotated quartercircle
+\def\chapno{ 14} \exno=2 % for exercise 14.3!
+\dangerexercise
+Use a {\sl rotated\/} quarter-circle to produce `{\manual\circc}\kern1pt'
+in font position `{\tt c}'.
+
+\bugonpage C129, lines 6--17 (8/5/98)
+
+\ninepoint
+\beginsyntax
+<path primary>\is<pair primary>\alt<path variable>
+ \alt[(]<path expression>[)]
+ \alt[reverse]<path primary>
+ \alt[subpath]<pair expression>[of]<path primary>
+<path secondary>\is<pair secondary>\alt<path primary>
+ \alt<path secondary><transformer>
+<path tertiary>\is<pair tertiary>\alt<path secondary>
+<path expression>\is<pair expression>\alt<path tertiary>
+ \alt<path subexpression><direction specifier>
+ \alt<path subexpression><path join>[cycle]
+<path subexpression>\is<path expression>
+ \alt<path subexpression><path join><path tertiary>
+\endsyntax
+
+\bugonpage C134, line 8 (3/4/95)
+
+\ninepoint\noindent
+of~$p$; if $t\le 0$, precontrol~$t$ of~$p$ is~$z_0$.
+In particular, if $t$ is an integer, postcontrol~$t$ of~$p$\cutpar
+
+\bugonpage C139, illustration (8/5/98)
+
+\eightpoint\noindent
+[Remove the labels {\tt 2r}, {\tt 2}, and {\tt 2l} below their dots.]
+
+\bugonpage C143, top two lines (3/4/95)
+
+\danger In order to have some transform variables to work with, it's necessary
+to `^{hide}' some declarations and commands before giving the next |expr|s:
+
+\bugonpage C147, lines 14, 16, and 19 (9/6/00)
+
+\noindent
+[Change `{\bf savepen}' to `{\it savepen}'.]
+
+\bugonpage C147, line 2 from the bottom (9/6/00)
+
+\ninepoint\noindent
+{\manual lmnj}'s {\bf penrazor} stands for
+`{\bf makepen} $\bigl((-.5,0)\dashto(.5,0)\dashto \cycle\bigr)$',
+and {\bf pensquare}\cutpar
+
+\bugonpage C171, line 19 (8/5/98)
+
+\ninepoint\noindent
+(\<path tertiary>) and
+(\<pair tertiary>). A pair expression is not considered to\cutpar
+
+\bugonpage C172, line 14 (8/5/98)
+
+\tenpoint\noindent
+been evaluated and changed to numeric tokens before being
+substituted for~$s$.\cutpar
+
+\bugonpage C175, line 23 (1/11/88)
+
+\ninepoint\noindent
+expand into a sequence of tokens. \
+(The language {\eightrm{SIMULA67}} demonstrated that it is\cutpar
+
+\bugonpage C206, minor changes to lines $-19$ to $-5$ (3/4/95)
+
+\vbox to70mm{\ninepoint
+\beginlines \advance\hsize.71pt
+|Path at line 15, before subdivision into octants:|
+|(1.53745,9.05345)..controls (1.53745,4.00511) and (5.75409,-0.00049)|
+| ..(10.85147,-0.00049)..controls (16.2217,-0.00049) and (20.46255,4.51297)|%
+             \kern.5em\null
+| ..(20.46255,9.94655)..controls (20.46255,14.99713) and (16.23842,19.00049)|
+      \kern-.71pt
+| ..(11.13652,19.00049)..controls (5.77066,19.00049) and (1.53745,14.48491)|%
+             \kern.5em\null
+| ..cycle|
+\smallskip
+|Cycle spec at line 15, after subdivision:|
+|(1.53745,9.05345) % beginning in octant `SSE'|
+|   ..controls (1.53745,6.58786) and (2.54324,4.371)|
+| ..(4.16621,2.74803) % segment 0|
+|% entering octant `ESE'|
+|   ..controls (5.8663,1.04794) and (8.24362,-0.00049)|
+| ..(10.85147,-0.00049) % segment 0|
+|% entering octant `ENE'|
+\endlines
+$\ldots$ and so on; there are lots more numbers! What does this all mean?
+Well, the first segment of the curve, from $(1.53745,9.05345)$ to
+$(10.85147,-0.00049)$,
+has been\cutpar}
+
+\bugonpage C207, minor changes to lines 1--23 (3/4/95)
+
+\ninepoint
+\begingroup\let\HRULE=\hrule \def\hrule{\HRULE width\hsize}
+\beginlines
+|Cycle spec at line 15, after subdivision and autorounding:|
+|(2,9.05348) % beginning in octant `SSE'|
+|   ..controls (2,6.50526) and (3.02194,4.22272)|
+| ..(4.6577,2.58696) % segment 0|
+|% entering octant `ESE'|
+|   ..controls (6.2624,0.98225) and (8.45786,0)|
+| ..(10.85873,0) % segment 0|
+|% entering octant `ENE'|
+\endlines
+Point $(1.53745,9.05345)$, where there was a vertical tangent, has been
+rounded to $(2,9.05348)$; point $(10.85147,-.00049)$, where there was
+\vadjust{\goodbreak}%
+a horizontal tangent, has been rounded to $(10.85873,0)$; the intermediate
+control points have been adjusted accordingly. \ (Rounding of $x$~coordinates
+has been done separately from $y$~coordinates.) \ Finally, with
+$\\{autorounding}=2$, additional adjustments are made so that the
+$45^\circ$ transition point will occur at what \MF\ thinks is a good spot:
+\beginlines
+|Cycle spec at line 15, after subdivision and double autorounding:|
+|(2,9.05348) % beginning in octant `SSE'|
+|   ..controls (2,6.6761) and (3.07103,4.42897)|
+| ..(4.78537,2.71463) % segment 0|
+|% entering octant `ESE'|
+|   ..controls (6.46927,1.03073) and (8.62749,0)|
+| ..(10.85873,0) % segment 0|
+|% entering octant `ENE'|
+\endlines
+(Notice that $4.78537+2.71463=7.50000$; when the slope
+is~$-1$ at a transition point\cutpar
+\endgroup
+
+\bugonpage C210, line $-7$ (8/5/98)
+
+\ninepoint\indent\qquad\alt\<numeric token primary>
+
+\bugonpage C210, line $-2$ (8/5/98)
+
+\ninepoint\indent\<numeric token primary>\is\<numeric token>\thinspace
+{\tt/}\thinspace\<numeric token>
+
+\bugonpage C211, line 16 (8/5/98)
+
+\ninepoint\indent\qquad\alt\<numeric token primary not followed by
+{\tt+} or {\tt-} or a numeric token>
+
+\bugonpage C213, lines 17--27 (8/5/98)
+
+\ninepoint
+\beginsyntax
+<path primary>\is<pair primary>\alt<path variable>\alt<path argument>
+ \alt[(]<path expression>[)]
+ \alt[begingroup]<statement list><path expression>[endgroup]
+ \alt[makepath]<pen primary>\alt[makepath]<future pen primary>
+ \alt[reverse]<path primary>
+ \alt[subpath]<pair expression>[of]<path primary>
+<path secondary>\is<pair secondary>\alt<path primary>
+ \alt<path secondary><transformer>
+<path tertiary>\is<pair tertiary>\alt<path secondary>
+<path subexpression>\is<path expression>
+ \alt<path subexpression><path join><path tertiary>
+\endsyntax
+
+\bugonpage C213, line $-4$ (8/5/98)
+
+\ninepoint\indent
+\<path expression>\is\<pair expression>\alt\<path tertiary>
+\endsyntax
+
+\bugonpage C234, line 6 (9/6/00)
+
+\ninepoint\noindent
+line~$z_1\to z_5$ that bisects $z_4\to z_2$, so it starts out in a
+south-by-southwesterly direction;\cutpar
+
+\bugonpage C246, line 5 of answer 14.15 (8/5/98)
+
+\ninepoint\indent
+\qquad/ length(postcontrol $t$ of $p$ $-$ point $t$ of $p$) {\bf enddef\/};
+
+\bugonpage C246, line 10 of answer 14.15 (8/5/98)
+
+\ninepoint\indent
+\qquad/ length(precontrol $t$ of $p$ $-$ point $t$ of $p$) {\bf enddef\/};
+
+\bugonpage C252, line $-6$ (8/5/98)
+
+\ninepoint\noindent
+$h+o$ and $\\{bot}\,y_4=-o$, so nothing needs to be done there.
+We should, however, say
+
+\bugonpage C257, large display on line 5 (3/4/95)
+
+\def\bb{$\,\left\{\vcenter\bgroup\halign\bgroup\hfil##\hfil\cr}
+\def\ee{\crcr\egroup\egroup\right\}\,$}
+\tenpoint\noindent
+\bb|boolean|\cr|numeric|\cr|pair|\cr|path|\cr
+|pen|\cr|picture|\cr|string|\cr|transform|\ee\<expression>; \
+\bb\<boolean>\cr\<numeric>\cr\<pair>\cr\<string>\cr\<transform>\ee
+ \bb|<|\cr|<=|\cr|=|\cr|<>|\cr|>=|\cr|>|\ee
+ \bb\<boolean>\cr\<numeric>\cr\<pair>\cr\<string>\cr\<transform>\ee;
+
+\bugonpage C261, line $-15$ (8/5/98)
+
+\tenpoint\textindent\bull {\it Hacks:\/} \ |gobble|, |gobbled|, |killtext|; \
+|capsule_def|; \ |numtok|.
+
+\bugonpage C286, line 15 (8/5/98)
+
+\ninepoint\noindent
+isn't entirely expanded by {\bf expandafter\/}; only \MF's first
+step in loop expansion\cutpar
+
+\bugonpage C299, line 2 (12/6/99)
+
+\ninepoint\noindent
+\begindisplay
+$\displaystyle t[u_1,\ldots,u_n]\;=\;\sum_{k=1}^n{n-1\choose k-1}
+ (1-t)^{n-k}t^{k-1}u_k,$
+\enddisplay
+
+\bugonpage C299, swap lines 11 and 12 (8/5/98)
+
+\ninepoint\begintt
+def lbrack = hide(delimiters []) lookahead [ enddef;
+let [[[ = [; let ]]] = ]; let [ = lbrack;
+\endtt
+
+\bugonpage C306, line 1 (11/4/98)
+
+\ninepoint\noindent
+| ligtable oct"013": "i" =: oct"016", "l" =: oct"017",   % ffi and ffl|
+
+\bugonpage C311, line 2 (8/5/98)
+
+\ninepoint\noindent
+$\\{fine}:=4-\\{eps}$, and $\\{breadth\_}[1]:=4-\\{eps}$.
+\ (A small amount~\\{eps} has been subtracted\cutpar
+
+\bugonpage C323, line $-3$ (8/5/98)
+
+\ninepoint\noindent
+statement occurs,
+the special string `|"title "|\thinspace\&\thinspace\<title>'
+is output. \ (This is how the\cutpar
+
+\bugonpage C332, lines 22--24 (8/5/98)
+
+\ninepoint
+\item{}be replicated so that the final
+proofs will be \\{rep} times bigger than usual, and the pattern will be clipped
+slightly at the edges so that discrete pixels can be seen plainly.
+
+
+\bugonpage C341, line 23 (10/10/96)
+
+\ninepoint
+\noindent|\def\:{\setbox0=\hbox{\noboundary\char\n\noboundary}%|
+
+\bugonpage C346, left column (9/6/00)
+
+\eightpoint
+|...| (bounded join), 18--19, 127, 248, $\underline{262}$.\par
+|...| (truncation of displayed context), 44.
+
+\bugonpage C346, and throughout the index (3/7/95)
+
+\eightpoint\noindent
+(Many index entries for rules of syntax in chapters 25--26
+should have been underlined)
+
+\bugonpage C350, left column (4/24/00)
+
+\eightpoint\noindent
+Evetts, Leonard Charles, 153.
+
+\bugonpage C351, right column (9/22/97)
+
+\eightpoint\noindent
+\llap{\lower1pt\hbox{*}}%
+|intersectiontimes|, $\underline{136}$, {\it178}, 213, {\it265}, {\it294},
+{\it298}.
+
+\bugonpage C353, right column (8/5/98)
+
+\eightpoint\noindent
+\<numeric token atom>, {\it delete this entry}.\par\noindent
+\<numeric token primary>, 72, $\underline{210}$.
+
+\bugonpage C354, left column (7/26/98)
+
+\eightpoint\noindent
+Orwell, George (= Blair, Eric Arthur), 85.
+
+\bugonpage C355, right column (3/7/95)
+
+\eightpoint\noindent
+|rt|, {\it23}, {\it77}, 80, {\it103}, 147, 151, $\underline{273}$.
+
+\bugonpage C361, lines 14--15 (4/29/97)
+
+\tenpoint
+\begintt
+email: {\tt TUG@tug.org}
+internet: {\tt http://www.tug.org/}
+}
+\endtt
+
+\bugonpage C361, bottom five lines (4/29/97)
+
+\begingroup  \def\TeX{T\kern-.2em\lower.5ex\hbox{E}\kern-.000em X}
+\baselineskip10pt
+\rightline{\eightssi Don't delay, subscribe today! That address again is}
+\rightline{\eightssi \TeX\ Users Group}
+\rightline{\eightssi email: \eighttt TUG\char`\@ tug.org}
+\rightline{\eightssi internet: \eighttt http://www.tug.org/}
+\smallskip
+\rightline{\eightss DONALD E. KNUTH, {\eightssi The \TeX book\/} (1996)}
+\endgroup
+
+% Volume D
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Dix, line ix (8/19/00)
+
+\tenpoint
+\textindent{\bull}``Interfacing with graphic objects'' by
+Ignacio Andr\'es Zabala Salelles,\cutpar
+
+\hsize=35pc
+
+\bugonpage D71, line 11 of section 178 (9/13/00)
+
+\ninepoint
+\noindent\quad\qquad\qquad$\{$ previous \\{mem\_end}, \\{lo\_mem\_max},
+  and \\{hi\_mem\_min} $\}$
+
+\bugonpage D132, line 6 of section 291 (9/13/00)
+
+\tenpoint\noindent
+$$=v_n+w_n\theta_0-u_n\bigl(v_1+w_1\theta_0-u_1(v_2+\cdots
+-u_{n-2}(v_{n-1}+w_{n-1}\theta_0-u_{n-1}\theta_0)\ldots{})\bigr),$$
+
+\bugonpage D213, line 7 (9/14/00)
+
+\tenpoint\noindent
+$(-y+\epsilon,
+x+y+\epsilon\delta)$. We should therefore round as if our skewed coordinates
+were $(x+\epsilon+\epsilon\delta,y-\epsilon)$\cutpar
+
+\bugonpage D349, line 4 of section 784 (9/14/00)
+
+\ninepoint\noindent
+{\bf procedure} \\{pack\_job\_name}($s\;$: \\{str\_number});\quad
+  $\{$ $s={}$|".log"|, |".gf"|, |".tfm"|, or \\{base\_extension} $\}$
+
+\bugonpage D451, line 11 (9/14/00)
+
+\tenpoint\noindent
+{\bf 1040}.\qquad The value of \\{cur\_mod} controls the \\{verbosity} in
+the \\{print\_exp} routine: If it's \\{show\_code},\cutpar
+
+\bugonpage D464, bottom line (9/14/00)
+
+\ninepoint\noindent
+\\{long\_help\_seen}: \\{boolean};\quad$\{$ has the long {\bf errmessage}
+   help been used? $\}$
+
+\bugonpage D551, Zabala entry (8/19/00)
+
+\eightpoint\noindent
+Zabala Salelles, Ignacio Andr\'es:\quad 812.
+
+% volume E
+\hsize=29pc
+\bugonpage Exiii, lines 3 and 4 from the bottom (7/17/98)
+
+\textindent{\bull}``Metamarks:
+Preliminary studies for a Pandora's Box of shapes''
+by Neenie Billawala, Stanford Computer Science report 1256 (Stanford,
+California,\cutpar
+
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+\def\ddashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu
+                      \hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+\bugonpage E87, bottom line (6/4/98)
+
+\rightline{\eightss--- JOHN SMITH, {\eightssi The Printer's Grammar\/}\enspace
+ (1755)} % p129
+
+\bugonpage E95, line 16 (8/8/98)
+
+\ninepoint\noindent
+\quad$\dashto z_{1r}\dashto z_{1l}\dashto{}$%
+ {\bf subpath} $(t,0)$ {\bf of\/} $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E95, line 11 from the bottom (8/8/98)
+
+\ninepoint\noindent
+\quad$\dashto z_{1r}\dashto z_{1l}\dashto{}$%
+ {\bf subpath} $(t,0)$ {\bf of\/} $(z_{3r}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E95, line 8 from the bottom (3/6/95)
+
+\ninepoint\noindent
+{\bf cmchar} |"Extensible vertical arrow--extension module"|;
+
+\bugonpage E97, line 8 from the bottom (3/6/95)
+
+\ninepoint\noindent
+{\bf cmchar} |"Extensible double vertical arrow--extension module"|;
+
+\bugonpage E113, line 9 (3/6/95)
+
+\ninepoint\noindent
+$x_5=.5[x_4,x_6]$; \ $x_4-x_6=1.2u$; \ $\\{lft}\,x_{5r}=\hbox{hround}
+   (.5w-.5\\{curve})$;
+
+\bugonpage E113, line 10 from the bottom (3/6/95)
+
+\ninepoint\noindent
+$x_5=.5[x_4,x_6]$; \ $x_4-x_6=4.8u$; \ $\\{lft}\,x_{5r}=\hbox{hround}
+   (.5w-.5\\{max\_size})$;
+
+\bugonpage E115, line 9 (3/6/95)
+
+\ninepoint\noindent
+$x_5=.5[x_4,x_6]$; \ $x_4-x_6=1.2u$; \ $\\{lft}\,x_{5r}=\hbox{hround}
+   (.5w-.5\\{curve})$;
+
+\bugonpage E115, line 12 from the bottom (3/6/95)
+
+\ninepoint\noindent
+$x_5=.5[x_4,x_6]$; \ $x_4-x_6=4.8u$; \ $\\{lft}\,x_{5r}=\hbox{hround}
+   (.5w-.5\\{max\_size})$;
+
+\bugonpage E147, lines 11--14 from the bottom (7/7/97)
+
+\ninepoint\noindent
+$\\{pos}_3(.8[\\{hair},\\{stem}],0)$; \ $\\{pos}_4(\\{vair},-90)$; \
+ $\\{pos}_5(\\{hair},-180)$;\par\noindent
+$\\{pos}_6(\\{vair},-270)$; \ ${pos}_7(\\{stem},-360)$; \
+ $\\{pos}_8(\\{vair},-450)$; \ ${pos}_9(\\{hair},-540)$;\par\noindent
+$x_0=x_1=x_9$; \ $\\{lft}\,x_{0l}=\hbox{hround}(1.5u-.5\\{hair})$; \
+ $x_2=x_4=x_6=x_8=.5w-.25u$;\par\noindent
+$\\{rt}\,x_{3r}=\hbox{hround}(w-1.75u)$; \ $\\{rt}\,x_{7r}=\hbox{hround}(w-u)$;
+
+\bugonpage E147, line 8 from the bottom (7/7/97)
+
+\ninepoint\noindent
+$y_5=.5[y_4,y_6]$; \ $\\{top}\,y_{6r}-\\{bot}\,y_{4r}=\\{vstem}+\\{eps}$; \
+$\\{bot}\,y_8=-\\{oo}$; \ $y_7=y_9=.55[y_6,y_8]$;
+
+\bugonpage E165, line 6 (2/8/97)
+
+\ninepoint\noindent
+$y_1+.5\\{hair}=h$; \ $x_1=x_2+.75u$; \
+ $\\{pos}_1(\\{hair}+\\{dw},\hbox{angle}(2(x_1-x_2),y_1-y_2)+90)$;
+
+\bugonpage E165, line 10 (2/8/97)
+
+\ninepoint\noindent
+$x_3=.5[x_2,x_4]$; \ $x_7-.25u=.5[x_6,x_8]$; \
+ $\\{rt}\,x_{8r}=\hbox{hround}(w-.5u)$;
+
+\bugonpage E187, line 9 (3/6/95)
+
+\ninepoint\noindent
+$\\{lft}\, x_{1l}=\\{lft}\, x_{2l}=\hbox{hround}(.5w-.5\\{shaved\_stem})$; \
+ $\\{top}\, y_1=h$; \ $\\{bot}\, y_2=0$;
+
+\bugonpage E189, line 8 (3/6/95)
+
+\ninepoint\noindent
+$\\{lft}\, x_{1l}=\\{lft}\, x_{2l}=\hbox{hround}(.5w-.5\\{shaved\_stem})$; \
+ $\\{top}\, y_1=h$; \ $\\{bot}\, y_2=0$;
+
+\bugonpage E233, line 21 (3/6/95)
+
+\ninepoint\noindent
+{\bf path} $p$; \
+$\{\{${\bf interim} $\\{superness}:=\\{more\_super}$; \
+  $p=\\{pulled\_super\_arc}_l(3,4)(\\{pull})\}\}$;
+
+\bugonpage E237, line 5 (8/6/98)
+
+\ninepoint\noindent
+$\\{lft}\,x_1={\rm hround}\,.5u$; \ $x_2=w-x_1$; \
+ $y_1=y_2=\\{good}.y\,.7[\\{x\_height},\\{asc\_height}]$;
+
+\bugonpage E239, line 7 from the bottom (3/6/95)
+
+\ninepoint\noindent
+$\\{lft}\,x_{6r}=\hbox{hround}\, u$; \
+$x_7=3u$; \ $x_8=w-3.5u$; \ $\\{rt}\,x_{9l}=\hbox{hround}(w-u)$;
+
+\bugonpage E253, line 2 from the bottom (8/9/98)
+
+\ninepoint
+\line{\quad$.\,.\,z_{3e}\{\\{down}\}\,.\,.\,\{z_{5l}-z_{4l}\}z_{4e}
+   \dashto z_{5e}\dashto z_{6e}$;\hfil  \% stroke}
+
+\bugonpage E263, line 21 (5/10/98)
+
+\ninepoint\noindent
+{\bf path} $p$; \
+$\{\{${\bf interim} $\\{superness}:=\\{more\_super}$; \
+  $p=\\{pulled\_super\_arc}_l(3,4)(\\{pull})\}\}$;
+
+\bugonpage E289, line 2 from the bottom (8/9/98)
+
+\ninepoint
+\line{\quad$.\,.\,z_{3e}\{\\{down}\}\,.\,.\,\{z_{5l}-z_{4l}\}z_{4e}
+   \dashto z_{5e}\dashto z_{6e}$;\hfil  \% stroke}
+
+\bugonpage E291, line 18 (3/6/95)
+
+\def\frac#1/#2{\leavevmode\kern.1em
+  \raise.5ex\hbox{\the\scriptfont0 #1}\kern-.1em
+  /\kern-.15em\lower.25ex\hbox{\the\scriptfont0 #2}}
+\ninepoint\noindent
+$x_4=\frac1/3[x_5,x_{3l}]$; \ $z_4=z_5+\\{whatever}*(15u,.1h)$;
+
+\bugonpage E297, line 17 (5/10/98)
+
+\ninepoint\noindent
+{\bf path} $p$; \
+$\{\{${\bf interim} $\\{superness}:=\\{more\_super}$; \
+  $p=\\{pulled\_super\_arc}_l(3,4)(\\{pull})\}\}$;
+
+\bugonpage E303, line 17 (5/10/98)
+
+\ninepoint\noindent
+{\bf path} $p$; \
+$\{\{${\bf interim} $\\{superness}:=\\{more\_super}$; \
+  $p=\\{pulled\_super\_arc}_l(3,4)(\\{pull})\}\}$;
+
+\bugonpage E309, line 7 from the bottom (5/8/98)
+
+\ninepoint\noindent
+\quad$y_{@0}=y_{@2l}-\\{bracket}-\\{eps}$;
+
+\bugonpage E313, line 7 from the bottom (5/8/98)
+
+\ninepoint\noindent
+\quad$y_{@0}=y_{@2l}+\\{bracket}+\\{eps}$;
+
+\bugonpage E319, line 8 (5/11/98)
+
+\ninepoint\noindent
+$\\{loop\_top}=$ {\bf if\/} \\{serifs}:
+ Vround .77$[\\{vair},\\{fudged.stem}]$ {\bf else}: \\{vair} {\bf fi};
+
+\bugonpage E373, lines 5 and 6 from the bottom (7/13/97)
+
+\ninepoint\noindent
+\quad$\\{top}\,y_{1r}=\hbox{vround}\, .95h+\\{oo}$; \
+$\\{top}\,y_{2r}=h+\\{oo}$; \ $y_3=.5h$;\par\noindent
+\quad$\\{bot}\,y_{4r}=-\\{oo}$; \
+$\\{bot}\,y_{5r}=\hbox{vround}\,.08h-\\{oo}$; \
+$y_{5l}:=\\{good}.y\, y_{5l}$; \ $x_{5l}:=\\{good}.x\,x_{5l}$;
+
+\bugonpage E381, lines 11 and 12 from the bottom (7/13/97)
+
+\ninepoint\noindent
+\quad$\\{top}\,y_{1r}=\hbox{vround}\, .93h+\\{oo}$; \
+$\\{top}\,y_{2r}=h+\\{oo}$; \ $y_3=.5h$;\par\noindent
+\quad$\\{bot}\,y_{4r}=-\\{oo}$; \
+$\\{bot}\,y_{5r}=\hbox{vround}\,.07h-\\{oo}$;
+
+\bugonpage E389, bottom two lines (8/7/98)
+
+\ninepoint\noindent
+\quad {\bf numeric} $\\{aa\_},\\{bb\_},\\{cc\_}$; 
+  \ $\\{bb\_}=b/y$;  \ $\\{cc\_}=c/y$;
+  \ $\\{aa\_}=a*a-\\{bb\_}*\\{bb\_}$;\par\noindent
+\quad $(a*(\\{cc\_}\mathbin{++}\hbox{sqrt}\,\\{aa\_})-\\{bb\_}*\\{cc\_})/\\{aa\_}$
+  {\bf enddef\/};
+
+\bugonpage E423, line 17 (8/8/98)
+
+\ninepoint\noindent\quad
+$x_{13}=x_{11}-.5$; \ $\\{top}\,y_{14r}=\min(\frac10/7\\{x\_height}+
+ .5\\{bulb\_diam},h)+1$; \ $\\{top}\,y_{11}=\\{x\_height}$;
+
+\bugonpage E427, line 21 (8/8/98)
+
+\ninepoint\noindent\quad
+$x_{23}=x_{21}-.5$; \ $\\{top}\,y_{24r}=\min(\frac10/7\\{x\_height}+
+ .5\\{bulb\_diam},h)+1$; \ $\\{top}\,y_{21}=\\{x\_height}$;
+
+\bugonpage E431, lines 18 and 19 (8/8/98)
+
+\ninepoint\noindent
+{\bf filldraw} $z_0\dashto(x_0,y_{2l})\dashto z_{1l}\{\\{right}\}\,.\,.\,
+  \{\\{left}\}z_{1r}$\par
+\noindent\quad$\dashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3r}\,.\,.\,\{2(x_0-x_3),y_0-y_3\}z_{5r})$
+
+\bugonpage E431, line 2 from the bottom (8/8/98)
+
+\ninepoint\line{\quad
+$\dashto z_{1l}\{\\{right}\}\,.\,.\,\{\\{left}\}z_{1r}\dashto
+  (x_0,y_{2r})\dashto{}$cycle;\hfill\% arrowhead and stem}
+
+\bugonpage E433, lines 13 and 14 (8/8/98)
+
+\ninepoint\noindent
+{\bf filldraw} $z_0\dashto(x_0,y_{2l})\dashto z_{1l}\{\\{left}\}\,.\,.\,
+  \{\\{right}\}z_{1r}$\par
+\noindent\quad$\dashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\,.\,.\,\{2(x_0-x_3),y_0-y_3\}z_{5r})$
+
+\bugonpage E433, line 2 from the bottom (8/8/98)
+
+\ninepoint\line{\quad
+$\dashto z_{1l}\{\\{left}\}\,.\,.\,\{\\{right}\}z_{1r}\dashto
+  (x_0,y_{2r})\dashto{}$cycle;\hfill\% arrowhead and stem}
+
+\bugonpage E463, line 15 (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1r}\,.\,.\,z_{1l}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3r}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E463, line 3 from the bottom (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1r}\,.\,.\,z_{1l}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E465, line 16 (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3r}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E465, line 3 from the bottom (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E467, line 18 (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3r}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E467, line 3 from the bottom (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{11l}\,.\,.\,z_{12r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{13l}\{z_{19}-z_{13}\}\,.\,.\,z_{15r})$
+
+\bugonpage E483, lines 12--14 from the bottom (3/6/95)
+
+\ninepoint\noindent
+{\bf beginarithchar}(oct$\,$|"004"|); \
+{\bf pickup} \\{fine}.\\{nib}; \
+{\bf pickup} \\{rule}.\\{nib};\par
+\line{{\bf numeric} \\{del};
+ \ $\\{del}=\\{dot\_size}-\\{currentbreadth}$;\hfill
+          \% $\\{currentbreadth}=\\{fine}$}
+\noindent
+$x_3-.5\\{del}=\\{good}.x(.5w-.5\\{del})$;
+ \ $\\{center\_on}(x_3)$;\par\noindent
+$y_3+.5del=\\{good}.y(\\{math\_axis}+\\{math\_spread}[.5\\{x\_height}
+   ,.6\\{x\_height}]+.5\\{del})$;
+
+\bugonpage E485, bottom line (6/4/98)
+
+\rightline{\eightss--- JOHN SMITH, {\eightssi The Printer's Grammar\/}\enspace
+ (1755)} % p80
+
+\bugonpage E489, line 4 (8/8/98)
+
+\ninepoint\noindent
+$\\{lft}\,x_6={\rm hround}\,u$; \ $x_2=w-x_6$; \ $\\{top}\,y_8=h$; \
+ $y_8-y_4=x_2-x_6$;
+
+\bugonpage E489, line 10 (8/8/98)
+
+\ninepoint\noindent
+$\\{lft}\,x_6={\rm hround}\,u$; \ $x_2=w-x_6$; \ $\\{top}\,y_8=h$; \
+ $y_8-y_4=x_2-x_6$; \ \\{circle\_points};
+
+\bugonpage E491, line 3 from the bottom (3/6/95)
+
+\def\SH{\raise.7ex\hbox{$\scriptstyle\#$}} % sharp sign for sharped units
+\ninepoint\noindent
+\quad $\\{spread}:=2\hbox{ceiling}(\\{spread}\SH*\\{hppp}/2)+\\{eps}$;
+ \  {\bf enddef\/};
+
+\bugonpage E507, line 15 (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1r}\,.\,.\,z_{1l}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3r}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E507, line 3 from the bottom (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{11r}\,.\,.\,z_{11l}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{13l}\{z_{19}-z_{13}\}\,.\,.\,z_{15r})$
+
+\bugonpage E509, line 17 (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E509, lines 3 and 4 from the bottom (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E511, line 17 (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E511, lines 3 and 4 from the bottom (8/8/98)
+
+\ninepoint\noindent\quad
+$\ddashto z_{1l}\,.\,.\,z_{1r}\ddashto{}${\bf subpath} $(t,0)$ {\bf of\/}
+  $(z_{3l}\{z_9-z_3\}\,.\,.\,z_{5r})$
+
+\bugonpage E541, bottom line (2/27/97)
+
+{\bf labels}\kern.05em$(1,2,3,5,6,7,8,9,10,11,12,13,14,15)$; \ {\bf endchar};
+
+\bugonpage E568, the example of {\tt cmtex8} (4/18/96)
+
+\eightpoint\indent
+(The word `{\tt logician}' should not be hyphenated.)
+
+\bugonpage E574, left column (3/6/95)
+
+\eightpoint\indent
+\\{currentbreadth}, 483, $\underline{545}$, 546.
+
+\bugonpage E575, right column (9/10/98)
+
+Holmes, Kris Ann, vi, vii.
+
+\bugonpage E576, right column (6/4/98)
+
+\eightpoint\noindent Delete the entry for Luckombe
+
+\bugonpage E579, left column (6/4/98)
+
+\eightpoint Smith, John, 87, 485.
+
+\bye
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.tex b/Master/texmf-dist/doc/generic/knuth-errata/errata.tex
new file mode 100644
index 00000000000..3a0d367f0ca
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.tex
@@ -0,0 +1,1802 @@
+% Bugs (sigh) in Computers \& Typesetting --- the most recent errata
+
+\tracingpages=1
+\input manmac
+\def\.#1{\hbox{\tt#1}}
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\endgraf}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting as of \today}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all substantial corrections made to {\sl Computers
+\& Typesetting\/} since the beginning of 2014.
+(More precisely, it lists errors corrected
+since the 19th printing of Volume~A, the 9th printing
+of Volume~B, the 8th printing of Volume~C, the 6th printing of Volume~D,
+and the 7th printing of Volume~E. % 2012 for A-D, 2013 for E
+But it omits changes that are ``purely cosmetic.'')
+Corrections made to the softcover version of {\sl The \TeX book\/},
+beginning with its 32nd printing, are
+the same as corrections to Volume~A\null. Corrections to the softcover
+version of {\sl The \slMF\kern1ptbook}, beginning with its 11th printing,
+are the same as corrections to Volume~C\null. Changes to the mini-indexes
+and master indexes of Volumes B, D, and~E are not shown here unless they are
+not obviously derivable from what has been shown. Some (or all) of these
+errors have been corrected in the most recent printings.
+\looseness=-1
+
+% volume A
+
+\bugonpage A34, line 3 from the bottom (01/09/20)
+
+\ninepoint\noindent
+not, you can say
+`\.{I\char`\\errorcontextlines=100} \.{\char`\\oops}' and try again. \ (That
+will usually\cutpar
+
+\bugonpage A43, line 6 (07/24/14)
+
+\tenpoint\noindent
+keyboard, or that have been
+pre\"empted for formatting?
+
+\bugonpage A49, cummings quote (08/03/19)
+
+(delete the period at the end of the line)
+
+\bugonpage A66, line 3 from the bottom (08/26/17)
+
+\ninepoint
+Such displays of box contents will be discussed further in
+Chapters 12 and~27.\cutpar
+
+\bugonpage A105, lines 9--16 (01/16/21)
+
+\ddanger If you say \.{\char`\\vadjust\char`\{}$\langle\,$vertical
+mode material$\,\rangle$\.{\char`\}} within a
+paragraph, \TeX\ will use internal vertical mode to insert the specified
+material into the vertical
+list that encloses the paragraph, immediately after whatever line
+contained the position of the \.{\char`\\vadjust}. For example, you can say
+`\.{\char`\\vadjust\char`\{\char`\\kern1pt\char`\}}'
+to increase the amount of space between lines of a
+paragraph if those lines would otherwise come out too close together.  \ (The
+\vadjust{\kern1pt}author
+did that in the current line, just to illustrate what happens.) \ Also,
+if you want to make sure that a page break will occur immediately after a
+certain line, you can say `\.{\char`\\vadjust\char`\{\char`\\eject\char`\}}'
+anywhere in that line.
+
+\bugonpage A122, lines 3--8 (11/24/19)
+
+\ninepoint\noindent
+\.{\char`\\count255}, \.{\char`\\dimen255}, \.{\char`\\skip255},
+\.{\char`\\muskip255}, and \.{\char`\\toks255} are
+traditionally kept available for such purposes.  Furthermore, plain \TeX\
+reserves \.{\char`\\dimen0} to \.{\char`\\dimen9},
+\.{\char`\\skip0} to \.{\char`\\skip9}, \.{\char`\\muskip0} to
+\.{\char`\\muskip9}, and \.{\char`\\box0} to \.{\char`\\box9}
+for ``scratchwork''; these registers
+are never allocated by the \.{\char`\\new...}\null\ operations.  We have seen that
+\.{\char`\\count0} through \.{\char`\\count9} are special,
+and \.{\char`\\box255} also turns out to
+be special; so those registers should be avoided unless you know what you
+are doing.
+
+\bugonpage A155, line 8 from the bottom (01/17/21)
+
+\ninepoint\indent
+\.{\char`\\mathopen\char`\{\char`\\hbox\char`\{\char`\$\char`\\left\char`\#1}%
+$\langle\,$strut$\,\rangle$\.{\char`\\right.\char`\$\char`\}\char`\}}
+
+\bugonpage A155, the bottom six lines (12/10/18)
+
+\ninepoint\noindent
+dividual symbols; \.{\char`\\left}$\,\ldots\,$\.{\char`\\right}
+constructions are treated as ``inner'' subformulas, which means that
+they will be surrounded by additional space in certain circumstances.
+All other subformulas are generally treated as ordinary symbols,
+whether they are formed by \.{\char`\\overline} or
+\.{\char`\\hbox} or \.{\char`\\vcenter} or
+by simply being enclosed in braces. Thus, \.{\char`\\mathord} isn't really
+a necessary part of the \TeX\ language; instead of typing
+`\.{\char`\$1\char`\\mathord,234\char`\$}' you can get the same
+effect from `\.{\char`\$1\char`\{,\char`\}234\char`\$}'.
+
+\bugonpage A158, line 19 (12/10/18)
+
+\ninepoint\indent
+Inner\quad is an inner atom produced by
+ `\.{\char`\\left}$\,\ldots\,$\.{\char`\\right}';
+
+\bugonpage A170, lines 18 and 19 (12/10/18)
+
+\ninepoint\noindent
+subformulas delimited by \.{\char`\\left} and \.{\char`\\right}
+are treated as type~Inner. The following table is
+used to determine the spacing between pairs of adjacent atoms:
+
+\bugonpage A171, line 19 from the bottom (06/15/19)
+
+\ninepoint\noindent
+formula produces a result essentially equivalent to
+`\.{\char`\\left(}$\langle\,$subformula$\,\rangle$\.{\char`\\right)}',
+when\cutpar
+
+\bugonpage A215, line 16 from the bottom becomes two lines (10/13/20)
+
+\ninepoint
+\item\bull Just after a token such as \.{\char`\$}$_3$
+that begins math mode, to see if
+another token of category 3 follows.
+
+\bugonpage A222, lines 21--23 (01/16/21)
+
+\ninepoint
+\halign{\indent#\hfil&\quad(see Chapter #)\hfil\cr
+\.{\char`\\hbox}$\langle\,$box specification$\,\rangle$%
+ \.{\char`\{}$\langle\,$horizontal mode material$\,\rangle$\.{\char`\}}&12\cr
+\.{\char`\\vbox}$\langle\,$box specification$\,\rangle$%
+ \.{\char`\{}$\langle\,$vertical mode material$\,\rangle$\.{\char`\}}&12\cr
+\.{\char`\\vtop}$\langle\,$box specification$\,\rangle$%
+ \.{\char`\{}$\langle\,$vertical mode material$\,\rangle$\.{\char`\}}&12\cr
+}
+
+\bugonpage A222, lines 11--13 from the bottom (01/16/21)
+
+\ninepoint\noindent
+ter~15. The \.{\char`\\vsplit} operation
+is also explained in Chapter~15. In math modes an additional
+type of box is available:
+\.{\char`\\vcenter}$\langle\,$box specification$\,\rangle$%
+ \.{\char`\{}$\langle\,$vertical mode material$\,\rangle$\.{\char`\}}
+(see Chapter~17).
+
+\bugonpage A232, line 14 (01/10/21)
+
+\ninepoint\noindent
+tabs outside; `\.{\char`\\global\char`\\settabs}' will not do what
+you might think it should.
+
+\bugonpage A233, lines 3--5 (04/27/15)
+
+\tenpoint\noindent
+Only two tabs are set in this case, because only two \.{\char`\&}'s
+appear in the sample line. \ (A sample line usually
+ends with~\.{\char`\&\char`\\cr}, as it does here,
+because text material between the last tab and \.{\char`\\cr}
+isn't used for anything.)
+
+\bugonpage A252, lines 5--7 (12/25/20)
+
+\ninepoint\noindent
+blank, and
+the footline is normally a centered page number, but you can specify any
+headline and footline that you want by changing the token lists
+\.{\char`\\headline} and \.{\char`\\footline}. For example,
+
+\bugonpage A253, lines 7--9 from the bottom (10/27/20)
+
+\ninepoint\indent
+\.{\char`\\everypar} or \.{\char`\\errhelp}, except that \TeX\
+retains the begin-group symbol~`\.{\char`\{}' at the beginning
+and the end-group symbol~`\.{\char`\}}' at the end. These
+grouping characters
+help to keep the output routine from interfering with what
+\TeX\ was doing\cutpar
+
+\bugonpage A256, line 19 (08/28/15)
+
+\ninepoint\indent
+\tt \char`\\baselineskip=24pt \char`\\lineskiplimit=0pt
+
+\bugonpage A277, lines 9 and 10 from the bottom (08/26/17)
+
+\ninepoint\indent
+$\langle\,$hyphenation assignment$\,\rangle$\is
+ \.{\char`\\hyphenation}$\langle\,$filler$\,\rangle$%
+ \.{\char`\{}$\langle\,$hyphenations$\,\rangle$\.{\char`\}}\par
+\qquad \alt \.{\char`\\patterns}$\langle\,$filler$\,\rangle$%
+ \.{\char`\{}$\langle\,$patterns$\,\rangle$\.{\char`\}}
+
+\bugonpage A286, bottom two lines {(and affecting the top lines
+of page 287)} (08/26/17)
+
+\ninepoint\noindent
+stands for zero or more \<assignment>
+commands other than \.{\char`\\setbox}, possibly with \<filler>.
+If the assignments are not followed by a \<character>, where
+\<character> stands\cutpar
+
+\bugonpage A287, lines 11--17  (04/22/20)
+
+\ninepoint
+\textindent{$\bull$} \.{\char`\\discretionary}%
+  \<disc text>\<disc text>\<disc text>.\enskip
+A \<disc text> has the form
+`\<filler>\.{\char`\{}\<horizontal mode material>\.{\char`\}}',
+where the material is processed in restricted horizontal mode and
+should contain only fixed-width things.
+More precisely, the horizontal list formed by each
+\<disc text> must consist only of characters, ligatures,
+kerns, boxes, and rules; there should be no glue or penalty items, etc.
+This command appends a discretionary item to the current list; see
+Chapter~14 for the meaning of a discretionary item. The space factor is
+not changed.
+
+\bugonpage A292, lines 8--10 (04/22/20)
+
+\ninepoint
+\textindent{$\bull$} \.{\char`\\discretionary}%
+  \<disc text>\<disc text>\<disc text>.\enskip
+This command has the same effect as in horizontal mode (see Chapter~25), but the
+third \<disc text> must produce an empty list.
+
+\bugonpage A299, line 11 from the bottom (11/01/20)
+
+\ninepoint\noindent
+is corrupted or was prepared for a different version of \TeX.
+
+\bugonpage A305, bottom line (06/30/20)
+
+\ninepoint\indent
+\tt \char`\\setbox0=\char`\\hbox\char`\{\char`\#1\char`\}%
+\char`\\advance\char`\\dimen0 by -\char`\\wd0 \char`\}\rm.
+
+\bugonpage A309, line 2 becomes two lines (12/06/20)
+
+\ninepoint\noindent
+represent text entered from the user's terminal, or with
+`\.{<insert>}', when they
+represent text inserted during error recovery).
+
+\bugonpage A316, lines 17 and 18 from the bottom (09/03/15)
+
+\ninepoint\noindent
+(The next line must also not be too tall.)
+Here \.{\char`\\specialstar} is a box of height zero and depth
+\.{\char`\\strutdepth},
+and it puts an asterisk in the left margin:
+
+\bugonpage A320, lines 5--9 from the bottom (06/27/15)
+
+\ninepoint\noindent
+{\bf 17.21.}\enspace Assigning \.{\char`\\delcode\char`\`\char`\{} 
+would not work to allow `\.{\char`\\left\char`\{}', because
+the brace has category~1 and isn't a legal \<delim>.
+Allowing brace delimiters would be a bad idea because it would
+mess up other constructions, such as arguments to macros, and
+components of alignments. Moreover, a user who
+gets away with `\.{\char`\\left\char`\{}'
+is likely to try also `\.{\char`\\bigl\char`\{}', which
+fails miserably.
+
+\bugonpage A326, line 12 (08/26/17)
+
+\ninepoint\noindent
+its natural width. The \.{\char`\\hbox} version also invokes
+\.{\char`\\everyhbox} and \.{\char`\\everymath}.
+
+\bugonpage A329, line 3 of answer 20.7 (05/15/19)
+
+\ninepoint\noindent
+the three tokens \.{!1}, \.{\char`\#2}, \.{[}$_1$; the
+\<replacement text> consists of the six tokens
+\.{\char`\{}$_1$, \.{\char`\#}$_6$,\cutpar
+
+\bugonpage A329, line 6 of answer 20.7 (05/15/19)
+
+\ninepoint\noindent
+is otherwise irrelevant. Thus, `\.{\char`\\def\char`\\!!1\char`\#2\char
+ `\#[\char`\{\char`\#\char`\#]!!\char`\#2]}'
+would produce an essentially\cutpar
+
+\bugonpage A329, line 5 from the bottom of answer 20.7 (05/15/19)
+
+\ninepoint\indent
+\.{!1<-x}
+
+\bugonpage A329, bottom line of answer 20.7 (05/15/19)
+
+\ninepoint\noindent
+final parameter in the parameter text;
+`\.{!1}' would have been rendered `\.{\char`\#1}'.
+
+\bugonpage A332, lines 13 and 14 (08/26/17)
+
+\ninepoint\noindent
+{\bf 21.10.}\enspace If you say
+`\.{\char`\{\char`\\let}\stretch
+\.{\char`\\the=0\char`\\edef}\stretch
+\.{\char`\\next}\stretch
+\.{\char`\{\char`\\write}\stretch
+\.{\char`\\cont}\stretch
+\.{\char`\{}\<token list>\.{\char`\}\char`\}\char`\\next}\stretch
+\.{\char`\}}',
+the \.{\char`\\write} will be exercuted after
+\.{\char`\\edef} expands everything except \.{\char`\\the}.
+
+\bugonpage A332, bottom line (11/15/19)
+
+\ninepoint\indent\quad
+\tt \char`\\+\char`\&\char`\{\char`\\bf end\char`\};\char`\\cr \
+ \char`\%\ note that the semicolon isn't bold
+
+\bugonpage A342, lines 12 and 13 (08/14/20)
+
+\tenpoint\noindent
+of plain \TeX\ format; but some of them are primitive (built in),
+such as `\.{\char`\\par}' (end of
+paragraph), `\.{\char`\\noindent}' (beginning of
+non-indented paragraph), and `\.{\char`\/}' (italic\cutpar
+
+\bugonpage A345, lines 10--13 from the bottom (06/27/15)
+
+\ninepoint\noindent
+Braces are used for grouping, when supplying
+arguments to macros; so they cannot also be used as math delimiters, or as
+arguments to macros such as \.{\char`\\big}. (One could change their catcodes
+to~12, and use some other pair of characters for grouping; but that
+would not be plain \TeX.)
+
+\bugonpage A346, lines 10--22 (11/24/19)
+
+\ninepoint\noindent
+number identification.) \ (2)~The registers
+\.{\char`\\count255}, \.{\char`\\dimen255}, \.{\char`\\skip255},
+\.{\char`\\toks255}, and \.{\char`\\muskip255}
+are freely available in the same way.
+\ (3)~All assignments to the scratch registers whose numbers are
+1,~3, 5, 7, and~9 should be \.{\char`\\global}; all assignments to the
+other scratch registers (0,~2, 4, 6, 8,~255) should be non-\.{\char`\\global}.
+\ (This prevents the phenomenon of ``save stack buildup'' discussed
+in Chapter~27.)
+\ (4)~Furthermore, it's possible to
+use any register in a group, if you ensure that \TeX's grouping
+mechanism will restore the register when you're done with the group, and
+if you are certain that other macros will not make global assignments
+to that register when you need it. \ (5)~But when a register is used
+by several macros, or over long spans of time, it should be allocated
+by \.{\char`\\newcount}, \.{\char`\\newdimen}, \.{\char`\\newbox},
+etc. \ (6)~Similar remarks
+apply to input/output streams used by \.{\char`\\read} and \.{\char`\\write},
+to math families used by \.{\char`\\fam}, to sets of hyphenation rules used by
+\.{\char`\\language}, and to insertions (which require
+\.{\char`\\box}, \.{\char`\\count}, \.{\char`\\dimen},
+and \.{\char`\\skip} registers all having the
+same number).\looseness=-1
+
+\bugonpage A347, line 6 (06/30/20)
+
+\ninepoint\noindent
+\tt \char`\\def\char`\\wlog\char`\{\char`\\immediate\char`\\write-1 \char`\}
+\ \char`\%\ this will write on log file (only)
+
+\bugonpage A347, line 10 (11/24/19)
+
+\ninepoint\noindent
+\tt \char`\\outer\char`\\def\char`\\newmuskip\char`\{\char`\\alloc@3%
+\char`\\muskip\char`\\muskipdef\char`\\@cclv\char`\}
+
+\bugonpage A347, line 14 (11/24/19)
+
+\ninepoint\noindent
+\tt \char`\\outer\char`\\def\char`\\newtoks\char`\{\char`\\alloc@5%
+\char`\\toks\char`\\toksdef\char`\\@cclv\char`\}
+
+\bugonpage A350, lines 15 and 16 from the bottom (01/17/21)
+
+\ninepoint\noindent
+format; it shouldn't cost much for people to acquire all the
+fonts of plain \TeX\ in addition to the ones that they really want. Second, it
+is desirable on many computer systems to\cutpar
+
+\bugonpage A364, line 5 from the bottom (01/14/21)
+
+\ninepoint\noindent
+\tt \char`\\def\char`\\fmtversion\char`\{3.1415926535\char`\} 
+\ \char`\%\ identifies the current format
+
+\bugonpage A370, lines 11 and 12 (08/26/17)
+
+\ninepoint\noindent
+close as possible to the ASCII conventions.
+\ (b)~Make sure that codes \oct{041}--\oct{046}, \oct{060}--\oct{071},
+\oct{136}, \oct{141}--\oct{146}, and \oct{160}--\oct{171} are present and that
+each unrepresentable in-\cutpar
+
+\bugonpage A373, lines 21 and 22 (01/17/21)
+
+\ninepoint\noindent
+and \.{\char`\\if...\char`\\fi}
+tests, as well as special operations like \.{\char`\\the}
+and \.{\char`\\input}, while the
+latter category includes the primitive commands listed in Chapters~24--26.
+The expansion of\cutpar
+
+\bugonpage A375, bottom three lines (06/30/20)
+
+\ninepoint\noindent
+|$$\generaldisplay$$| to be invoked, with |\eq| defined to be $\alpha$.
+Furthermore, when an equation number~$\beta$ is present, it should be stored
+in |\eqn|, and the test |\ifeqno| should be true.
+In such cases |\ifleqno| should distinguish |\leqno| from |\eqno|.
+Here\cutpar
+
+\bugonpage A398, lines 4 and 5 (08/26/17)
+
+\ninepoint\indent
+|\setbox2=\lastbox \setbox\footins=\vbox{\box2}|\par
+\smallskip\noindent
+since |\lastbox| will be the result of\/ |\rigidbalance|, which is an hbox.
+
+\bugonpage A407, line 5 from the bottom (06/30/20)
+
+\ninepoint\noindent\quad
+|  \interlinepenalty5000\def\par{\endgraf\penalty5000 }}|
+
+\bugonpage A413, line 11 from the bottom (05/14/19)
+
+\ninepoint\indent
+The computer file |texbook.tex| that generated {\sl The \TeX book\/} begins
+with a\cutpar
+
+\bugonpage A418, line 4 (05/14/19)
+
+\ninepoint\noindent
+\TeX\ commands
+that look like this in the file |texbook.tex|:
+
+\bugonpage A420, line 11 (06/30/20)
+
+\ninepoint\noindent
+|\def\bull{\vrule height.9ex width.8ex depth-.1ex \relax} % square bullet|
+
+\bugonpage A423, line 16 (06/30/20)
+
+\ninepoint\noindent
+|  \vrule height6pt depth2pt width0pt \relax} % a strut for \insert\margin|
+
+\bugonpage A445, lines 10--14 (12/10/18)
+
+\ninepoint
+\textindent{\bf 15e.} Enclose the vbox that was constructed in Rule 15c or 15d by
+delimiters $(\lambda,\rho)$
+whose height plus depth is at least $\sigma_{20}$, if $C>T$, and at
+least $\sigma_{21}$ otherwise. Shift the delimiters up or down so that they are
+vertically centered with respect to the axis. Replace the generalized
+fraction by an Ord atom whose nucleus is the resulting sequence of three boxes
+($\lambda$, vbox, $\rho$). Go to rule~19.
+
+\bugonpage A446, the bottom three lines of Rule 19 become four lines (01/10/21)
+
+\ninepoint\noindent
+atom and the right boundary item to
+a Close atom. The entire resulting list now becomes the nucleus of an
+Inner atom. \ (All of the calculations in this step are done with
+$C$ equal to the starting style of the math list; style items in the
+middle of the list do not affect the style of the right boundary item.)
+
+\bugonpage A454, lines 17 and 18 from the bottom (04/13/20)
+
+\ninepoint\noindent
+of the process; the trial word consists of all the letters found in admissible
+items, up to a maximum of~63. Notice that all of these letters are in font~$f$.
+
+\bugonpage A458 and following, selected amendments to the index (01/18/21)
+
+\eightpoint
+|[1]| (progress report), 23, $\underline{119}$.\par
+|\aa| ( \aa\ ), {\it52}, $\underline{356}$.\par
+|\AA| ( \AA\ ), {\it52}, $\underline{356}$.\par
+\<disc text>, $\underline{287}$, 292.\par
+\<general text>, $\underline{276}$, 279, 280.\par
+\<horizontal mode material>, 278, 285, 287.\par
+integral signs, {\sl see\/} |\int|, |\oint|, |\smallint|.\par
+\<math mode material>, 287, 289--293.\par
+|\null|, 311, {\it312}, {\it316}, {\it332}, {\it335}, $\underline{351}$, {\it354}, {\it360}--{\it362}, {\it419}.\par
+|\o| ( \o\ ), {\it52}, $\underline{356}$.\par
+|\O| ( \O\ ), {\it52}, $\underline{356}$.\par
+programs, for computers, 38, 165, {\it234}.\par
+repeating templates, {\sl see\/} periodic preambles.\par
+replacement text, {\it200}--{\it204}, 212, 280, 300, 329.\par
+right delimiters, {\sl see\/} closings.\par
+struts, $\underline{82}$, 125, 131, 142, 155, 178, 245--247, 255, 329, 416, 422, 423.\par
+\<vertical mode material>, 278, 280--282, 290.
+
+
+% volume B
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\dts{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Bv {(formerly Bvii)}, bottom two lines (01/15/21)
+
+\eightpoint\noindent
+all of those changes.
+I~now believe that the final bug was discovered on 22 October 2020
+and removed in version 3.141592653. % on 12 January 2021
+The finder's fee has converged to \$327.68.
+
+\hsize=35pc
+
+\bugonpage B2, line 10 from the bottom (01/15/21)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]3.141592653\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B4, line 8 of \S7 (04/02/17)
+
+\tenpoint\noindent
+diagnostic information for \.{\char`\\tracingparagraphs},
+\.{\char`\\tracingpages}, and \.{\char`\\tracingrestores}.
+
+\bugonpage B21, lines 33 and 34 (04/02/17)
+
+\def\Oct#1{\hbox{\rm\char'23\kern-.2em\it#1\/\kern.05em}} % octal constant
+\tenpoint\noindent
+$[\Oct{41}\to\Oct{46},\Oct{60}%
+\to\Oct{71},\Oct{136},\Oct{141}\to\Oct{146},\Oct{160}\to\Oct{171}]$ must be printable.
+Thus, at least 80 printable characters are needed.
+
+\bugonpage B28, lines 3 and 4 (04/02/17)
+
+\tenpoint\noindent
+not serious since we assume that this
+part of the program is system dependent.
+
+\bugonpage B28, line 2 from the bottom (04/02/17)
+
+\ninepoint\noindent\quad
+{\bf var} $k$: $0\dts23$;\quad$\{\,$index to current digit; we assume
+ that $\vert n\vert<10^{23}\,\}$
+
+\bugonpage B35, line 2 of \S83 becomes two lines (06/27/20)
+
+\ninepoint\noindent\quad
+{\bf loop begin} \\{continue}: {\bf if} $\\{interaction}\ne\\{error\_stop\_mode}$
+  {\bf then return};\par
+\noindent\qquad
+\\{clear\_for\_error\_prompt}; \ \\{prompt\_input}(\.{"?\]"});
+
+\bugonpage B36, line 11 of \S84 (07/03/20)
+
+\ninepoint\noindent\quad
+\.{"E"}: {\bf if} $\\{base\_ptr}>0$ {\bf then if}
+ $\\{input\_stack}[\\{base\_ptr}].\\{name\_field}\ge256$ {\bf then}
+
+\bugonpage B36, line 5 of \S85 becomes two lines (07/03/20)
+
+\ninepoint\noindent\quad
+{\bf if} $\\{base\_ptr}>0$ {\bf then}\par
+\noindent\qquad
+{\bf if} $\\{input\_stack}[\\{base\_ptr}].\\{name\_field}\ge256$ {\bf then}
+\\{print}(\.{"E\]to\]edit\]your\]file."}
+
+\bugonpage B40, line 5 from the bottom (08/07/20)
+
+\ninepoint\noindent\qquad
+(\.{"Try\]to\]insert\]an\]instruction\]for\]me\](e.g.,\]%
+        \char`\`I\char`\\showlists\char`\'),"})
+
+\bugonpage B58, lines 2 and 3 of \S136 (10/11/20)
+
+\tenpoint\noindent
+the values corresponding to `\.{\char`\\hbox\char`\{\char`\}}'.
+The \\{sub\_type} 
+field is set to \\{min\_quarterword}, for historic reasons that are no
+longer relevant.
+
+\bugonpage B88, line 16 (10/22/20)
+
+\tenpoint\noindent
+The mode is temporarily set to zero while processing \.{\char`\\write} texts.
+
+\bugonpage B102, lines 3 and following of \S241 (12/11/20)
+
+\tenpoint\noindent
+information, something special
+is needed. The program here simply assumes that suitable values appear in
+the global variables \\{sys\_time}, \\{sys\_day}, \\{sys\_month}, and
+\\{sys\_year} (which are initialized to noon on 4 July 1776,
+in case the implementor is careless).
+\smallskip
+\ninepoint\noindent
+{\bf procedure} \\{fix\_date\_and\_time};\par
+\noindent\quad{\bf begin}
+$\\{sys\_time}\gets12\ast60$; \
+$\\{sys\_day}\gets4$; \
+$\\{sys\_month}\gets7$; \
+$\\{sys\_year}\gets1776$;\quad
+$\{\,$self-evident truths$\,\}$\par
+\noindent\quad$\\{time}\gets\\{sys\_time}$;\quad
+  $\{\,$minutes since midnight$\,\}$\par
+\noindent\quad$\\{day}\gets\\{sys\_day}$;\quad$\{\,$day of the month$\,\}$\par
+\noindent\quad$\\{month}\gets\\{sys\_month}$;\quad$\{\,$month of the year$\,\}$\par
+\noindent\quad$\\{year}\gets\\{sys\_year}$;\quad$\{\,$Anno Domini$\,\}$\par
+\noindent\quad{\bf end};
+
+\bugonpage B103, replacement for \S246 (12/11/20)
+
+\tenpoint\noindent
+{\bf 246.}\quad Of course we had better declare a few more global variables,
+if the previous routines are going to work.
+\smallskip
+\ninepoint\noindent
+$\langle\,$Global variables {\sevenrm\kern.5em13}$\,\rangle+\equiv$\par
+\noindent\\{old\_setting}: $0\dts\\{max\_selector}$;\par
+\noindent\\{sys\_time}, \\{sys\_day}, \\{sys\_month}, \\{sys\_year}: \\{integer};
+\quad$\{\,$date and time supplied by external system$\,\}$
+
+\goodbreak
+\bugonpage B122, lines 9 and 10 of \S291 (10/12/20)
+
+\tenpoint\noindent\quad
+The enclosing \.{\char'173} and \.{\char'175} characters of a macro
+definition are omitted, but an output routine
+will be enclosed in braces.
+
+\bugonpage B143, lines 2, 3, 4 become four lines (01/15/17)
+
+\tenpoint\noindent
+routines that should be aborted, but we can sketch the
+ideas here:  For a runaway definition or a runaway balanced text,
+we will insert a right brace; for a
+runaway preamble, we will insert a special \.{\char`\\cr} token and a right
+brace; and for a runaway argument, we will set \\{long\_state} to
+\\{outer\_call} and insert \.{\char`\\par}.
+
+\bugonpage B188, line 8 (04/02/17)
+
+\ninepoint\noindent
+{\bf function} \\{str\_toks}$(b:\\{pool\_pointer})$: \\{pointer};\quad
+ $\{\,$converts \\{str\_pool}$[b\dts\\{pool\_ptr}-1]$ to a token list$\,\}$
+
+\bugonpage B192, line 17 (10/22/20)
+
+\ninepoint\noindent\quad
+{\bf label} \\{found}, \\{continue}, \\{done}, \\{done1}, \\{done2};
+
+\bugonpage B192, line 3 of \S474 (10/22/20)
+
+\ninepoint\noindent\qquad
+{\bf begin} \\{continue}: \\{get\_token};\quad$\{\,$set \\{cur\_cmd},
+  \\{cur\_chr}, \\{cur\_tok}$\,\}$
+
+\bugonpage B193, line 4 of \S476 (05/20/20)
+
+\ninepoint\noindent\quad
+{\bf if} $\\{cur\_tok}<\\{left\_brace\_limit}$ {\bf then}
+
+\bugonpage B193, line 10 of \S476 becomes two lines (10/22/20)
+
+\ninepoint\noindent\qquad
+\\{help2}(\.{"I\char`\'m\]going\]to\]ignore\]the\]\#\]sign\]you\]just\]used,"})\par
+\noindent\qquad
+(\.{"as\]well\]as\]the\]token\]that\]followed\]it."});
+\\{error}; {\bf goto} \\{continue};
+
+\bugonpage B196, line 5 from the bottom (02/17/18)
+
+\ninepoint\noindent\qquad\quad
+\\{help1}(\.{"This\]\char`\\read\]has\]unbalanced\]braces."});
+$\\{align\_state}\gets1000000$;
+$\\{limit}\gets0$;
+\\{error};
+
+\bugonpage B199, lines 1--3 of \S494 (10/25/20)
+
+\tenpoint\noindent
+{\bf 494.} \ \ Here is a procedure that ignores text until coming to an \.{\char`\\or},
+\.{\char`\\else}, or \.{\char`\\fi} at the current level
+of $\.{\char`\\if}\ldots\.{\char`\\fi}$
+nesting. After it has acted, \\{cur\_chr} will indicate the token that
+was found, but \\{cur\_tok} will not be set (because this makes the
+procedure run faster).
+
+
+\bugonpage B214, lines 2--6 of \S536 (12/11/20)
+
+\ninepoint\noindent\quad
+{\bf begin} \\{wlog}(\\{banner});
+\\{slow\_print}(\\{format\_ident});
+\\{print}(\.{"\]\]"});
+\\{print\_int}(\\{sys\_day});
+\\{print\_char}(\.{"\]"});\par
+\noindent\quad
+$\\{months}\gets\.{\char`\'JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC\char`\'}$;\par
+\noindent\quad
+{\bf for} $k\gets3\ast\\{sys\_month}-2$ {\bf to} $3\ast\\{sys\_month}$
+{\bf do} \\{wlog}(\\{months}[$k$]);\par
+\noindent\quad
+\\{print\_char}(\.{"\]"});
+\\{print\_int}(\\{sys\_year});
+\\{print\_char}(\.{"\]"});
+\\{print\_two}(\\{sys\_time} {\bf div} 60);
+\\{print\_char}(\.{":"});\par
+\noindent\quad
+\\{print\_two}(\\{sys\_time} {\bf mod} 60);
+
+\bugonpage B214, line 2 of \S537 becomes two lines (10/29/20)
+
+\tenpoint\noindent
+command is being processed.
+Beware: For historic reasons, this code foolishly conserves a tiny bit
+of string pool space; but that can confuse the interactive `\.E' option.
+
+\bugonpage B214, bottom line (10/29/20)
+
+\ninepoint\noindent
+{\bf if} $\\{name}=\\{str\_ptr}-1$ {\bf then}
+\ $\{\,$conserve string pool space (but see note above)$\,\}$
+
+\bugonpage B219, lines 18--20 of \S545 (09/19/19)
+
+\tenpoint\noindent
+so-called boundary character of this font;
+the value of \\{next\_char} need not lie between \\{bc} and~\\{ec}.
+If the very last instruction of the \\{lig\_kern} array has $\\{skip%
+\_byte}=255$,
+there is a special ligature/kerning program for a boundary character at the
+left, beginning at location $256\ast\\{op\_byte}+$\cutpar
+
+\bugonpage B282, line 1 {(and change lines 20--23 accordingly)} (04/02/17)
+
+\tenpoint\noindent
+{\bf 682.} Each portion of a formula is classified as Ord, Op, Bin, Rel, Open,
+Close, Punct, or Inner, for\cutpar
+
+\bugonpage B299, line 4 from the bottom of \S722 (10/06/20)
+
+\ninepoint\noindent\qquad\quad
+{\bf begin} \\{char\_warning}(\\{cur\_f}, \\{qo}(\\{cur\_c}));
+$\\{math\_type}(a)\gets\\{empty}$;
+$\\{cur\_i}\gets\\{null\_character}$;
+
+\bugonpage B318, lines 16 and 17 of \S761 become one (03/25/19)
+
+\ninepoint\noindent
+\\{fraction\_noad}: $s\gets\\{fraction\_noad\_size}$;
+
+\bugonpage B333, line 5 of \S793 becomes two lines (01/10/20)
+
+\ninepoint\noindent\quad
+$\\{cur\_loop}\gets\\{link}(\\{cur\_loop})$;
+$\\{link}(p)\gets\\{new\_glue}(\\{glue\_ptr}(\\{cur\_loop}))$;\par
+\noindent\quad
+$\\{subtype}(\\{link}(p))\gets\\{tab\_skip\_code}+1$;
+
+\bugonpage B348, insert a new line after line 5 of \S826 (01/15/17)
+
+\ninepoint\noindent\qquad
+{\bf stat if} $\\{tracing\_paragraphs}>0$ {\bf then}
+\\{end\_diagnostic}(\\{true}); \ {\bf tats}
+
+\bugonpage B348, insert a new line to be the seventh line after the previous change (01/15/17)
+
+\ninepoint\noindent\qquad
+{\bf stat if} $\\{tracing\_paragraphs}>0$ {\bf then}
+\\{begin\_diagnostic}; \ {\bf tats}
+
+\bugonpage B377, line 6 (10/31/20)
+
+\ninepoint\noindent
+\\{hn}: $0\dts64$; \ $\{\,$the number of positions occupied in \\{hc};
+                       not always a \\{small\_number}$\,\}$
+
+\bugonpage B417, mini-index (04/02/17)
+
+\eightpoint\noindent
+The entry `\\{height}, \S981.' here and on many later
+odd-numbered pages should be `$\\{height}=\rm macro$, \S135.'
+
+\bugonpage B522, line 3 of \S1306. (10/25/20)
+
+\tenpoint\noindent
+to be in the range $a\le x\le b$.
+System error messages should be suppressed when undumping.
+
+\bugonpage B533, lines 5--8 of \S1333. (10/15/20)
+
+\tenpoint\noindent
+loop.
+(Actually there's one way to get error messages, via \\{prepare\_mag};
+but that can't cause infinite recursion.)\par
+\noindent\quad
+If \\{final\_cleanup} is bypassed, this program doesn't bother to
+close the input files that may still be open.
+
+\bugonpage B533, line 12 of \S1333. (11/29/20)
+
+\ninepoint\noindent\quad
+{\bf begin} $\langle\,$Finish the extensions{\sevenrm\kern.5em1378}$\,\rangle$;
+$\\{new\_line\_char}\gets-1$;
+
+\bugonpage B534, line 6 of \S1335. (11/29/20)
+
+\ninepoint\noindent\quad
+{\bf begin} $c\gets\\{cur\_chr}$;
+{\bf if} $c\ne1$ {\bf then} $\\{new\_line\_char}\gets-1$;
+
+\bugonpage B537, line 18 of \S1338 becomes two lines (10/05/20)
+
+\ninepoint\noindent\quad
+{\bf begin} \\{clear\_terminal};\par
+\noindent\quad
+{\bf loop}
+
+\bugonpage B537, lines 11 and 12 from the bottom of \S1338
+  become three lines (04/02/17)
+
+\ninepoint\noindent\qquad\qquad
+{\bf begin goto} \\{breakpoint};\par
+\noindent\qquad\qquad\quad$\{\,$go to every declared label at least once$\,\}$\par
+\noindent\qquad\quad\\{breakpoint}: $m\gets0$;
+ \.{@\char`\{\char`\'BREAKPOINT\char`\'@\char`\}}
+
+\bugonpage B600, the bottom five lines (05/14/19)
+
+\tenpoint\noindent
+they occupy in a typical production system
+(executable code size for dark blocks, global data size for light blocks).
+In this way the chart indicates a total of about
+$12\times22=264${\ninerm K} bytes of memory, plus
+$12\times10=120${\ninerm K} for the
+dynamic memory region not shown explicitly. The dynamic memory
+is often considerably larger in practice, because it is desirable to
+accommodate large macro packages and large pages.
+
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\dashto{\mathrel{\hbox{-\thinspace-\kern-.05em}}}
+\def\ddashto{\mathrel{\hbox{-\thinspace-\thinspace-\kern-.05em}}}
+\def\tension{\mathop{\rm tension}}
+\def\controls{\mathop{\rm controls}}
+\def\and{\,{\rm and}\,}
+
+\bugonpage Cx, line 4 from the bottom (06/14/20)
+
+\count255=1
+\def\diamondleaders{\global\advance\count255 by 1
+  \ifodd\count255 \kern-10pt \fi
+  \leaders\hbox to 20pt{\ifodd\count255 \kern13pt \else\kern3pt \fi
+    .\hss}}
+\line{\strut
+    \hbox to\parindent{\bf\hbox to 1em{\hss20}\hss}%
+    \rm More About Macros\diamondleaders\hfil\hbox to 2em{\hss175}}
+
+\bugonpage C39, lines 10 and 11 become three lines (07/04/20)
+
+\tenpoint\noindent
+that has already been designed. All you'll see is
+`|(io.mf| |The| |letter| |O| |[79])|' or possibly only `|(io.mf| |[79])|',
+followed by~`|*|'. Now the fun starts: You should type
+
+\bugonpage C68, lines 9, 28, 35, 36, 38 (11/11/17)
+
+\ninepoint
+\halign{\indent\hbox to 160pt{\tt#\hfil}&\tt#\hfil\cr
+uniformdeviate -100&-36.1628\cr
+z slanted 1/6&(0.16667y+x,y)\cr
+(a,b)zscaled(3,4)&(-4b+3a,3b+4a)\cr
+(a,b)zscaled dir 30&(-0.5b+0.86603a,0.86603b+0.5a)\cr
+(a,b)dotprod(3,4)&4b+3a\cr
+}
+
+\bugonpage C72, lines 4--18 (07/16/20)
+
+\ninepoint\noindent
+\beginsyntax
+<numeric atom>\is<numeric variable>
+ \alt<numeric token primary>
+ \alt[(]<numeric expression>[)]
+ \alt[normaldeviate]
+ \alt[length]<string primary>
+ \alt[length]<path primary>
+ \alt[length]<pair primary>
+ \alt[angle]<pair primary>
+ \alt[xpart]<pair primary>
+ \alt[ypart]<pair primary>
+ \alt<numeric operator><numeric primary>
+<numeric token primary>\is<numeric token>[/]<numeric token>
+ \alt<numeric token not followed by %
+  `{\tt/}$\thinspace\langle$numeric token$\rangle$'\thinspace>
+<numeric primary>\is<numeric atom not followed by {[\char'133]<expression>[,]}>
+ \alt<numeric atom>[\char'133]<numeric expression>%
+   [,]<numeric expression>[\char'135]
+\endsyntax
+
+\bugonpage C76, lines  8--16 from the bottom (11/11/17)
+
+\newdimen\longesteq
+\setbox0=\hbox{\indent$z_{12}-z_{11}=z_{14}-z_{13}$\quad}
+\longesteq=\wd0
+\tenpoint\noindent \hangindent\longesteq \hangafter0
+tom edge of the type.
+\ (With plain \MF's {\bf beginchar} each
+character has a ``bounding box'' that runs from $(0,h)$
+at the upper left and $(w,h)$ at the upper right to $(0,-d)$ and~$(w,-d)$
+at the lower left and lower right; variable $d$ represents the depth of
+the type. The values of $w$, $h$, and~$d$ might change from character to
+character, since the individual pieces of type need not have the same size
+in a computer-produced font.)
+
+\bugonpage C80, line 14 (06/13/20)
+
+\tenpoint\indent
+\\{penpos}\<suffix>(\<unknown>,\thinspace\<known>).
+
+\bugonpage C83, line 16 (06/13/20)
+
+\ninepoint\indent
+|### 0.5a=-c-0.5b+1.5|
+
+\bugonpage C83, line 19 (06/13/20)
+
+\ninepoint\noindent
+the only
+dependent variable is now $d$, which equals $0.5c+0.75b+0.75$. \ (This is\cutpar
+
+\bugonpage C96, line 13 from the bottom (10/31/20)
+
+\tenpoint\noindent
+illustrates the
+use of $u\0$, $s\0$, $\\{ht}\0$, \\{logo\_pen}, \\{leftstemloc}, $o$,
+\\{xgap}, and \\{barheight}:
+
+\bugonpage C106, lines 19--21 (07/03/20)
+
+\ninepoint\noindent
+pixels. \ (Some typesetting
+systems use both of these device-dependent amounts to alter their current
+position on a page, just after typesetting each character. Other systems,
+like typical |dvi| software associated with \TeX, assume that $\\{chardy}=0$
+but use \\{chardx}\cutpar
+
+\bugonpage C113, lines 5--11 from the bottom (07/20/20)
+
+\def\cycle{\hbox{\rm cycle}}
+\ninepoint\noindent
+\begindisplay
+$s\0:=5\\{pt}\0$; \ {\bf define\_pixels}$(s)$; \ \%  side of the square\cr
+$z_1=(0,0)$; \ $z_2=(s,0)$; \ $z_3=(0,s)$; \ $z_4=(s,s)$;\cr
+{\bf for} $k=1$ {\bf upto} 4:
+ $z[k+4]=z[k]+({2\over3}s,{1\over3}s)$; \ {\bf endfor}\cr
+{\bf pickup pencircle} scaled $.4\\{pt}$; \
+{\bf draw} $z_5\dashto z_6\dashto z_8\dashto z_7\dashto \cycle$;\cr
+{\bf pickup pencircle} scaled $1.6\\{pt}$; \
+{\bf erase draw} $z_2\dashto z_4\dashto z_3$;\cr
+{\bf pickup pencircle} scaled $.4\\{pt}$; \
+{\bf draw} $z_1\dashto z_2\dashto z_4\dashto z_3\dashto \cycle$;\cr
+{\bf for} $k=1$ {\bf upto} 4:
+ {\bf draw} $z[k]\dashto z[k+4]$; \ {\bf endfor}.\cr
+\enddisplay
+
+\bugonpage C114, line 7 (07/20/20)
+
+\ninepoint\indent
+{\bf for} $k=0$ {\bf upto} 4: \ $z[k]=\\{center}+(\\{radius},0)$
+  rotated$(90+{360\over5}k)$; \ {\bf endfor}
+
+\bugonpage C128, lines 13 and 14 (06/13/20)
+
+\ninepoint\noindent
+changed. Plain \MF\ has a {\bf tensepath} operation
+that does this. For example, {\bf tensepath}~\\{unitsquare}~$=$
+$(0,0)\ddashto(1,0)\ddashto(1,1)\ddashto(0,1)\ddashto\cycle$.
+
+\bugonpage C136, lines 18 and 19 (07/17/20)
+
+\ninepoint\noindent
+only
+about 0.28 with respect to the initial and final directions; since \MF\ insists
+that tensions be at least~0.75, this anomalous path could never have arisen
+if the control\cutpar
+
+\bugonpage C155, line 7 (10/07/20)
+
+\tenpoint\indent
+\<program>\is\<statement list>\<statement>\thinspace|end|
+
+\bugonpage C160, lines 7--9 (06/25/20)
+
+\ninepoint\noindent
+might produce a transcript
+that includes the following diagnostic information:
+\begintt
+rotatedaround(EXPR0)(EXPR1)->
+ shifted-(EXPR0)rotated(EXPR1)shifted(EXPR0)
+\endtt
+
+\bugonpage C165, lines 5--7 from the bottom (11/11/17)
+
+\ninepoint\noindent
+(i.e., parameters in parentheses),
+then we name zero or one or two undelimited parameters.
+Then comes an `$=$'~sign,
+followed by the replacement text, and {\bf enddef}. The `$=$'~sign might also
+be~`$:=$'\thinspace; both mean the same thing.
+
+\bugonpage C171, lines 18--20 (08/16/20)
+
+\ninepoint\indent
+Chapter~14's syntax rules for
+\<path primary>, via \<pair primary>.
+A pair expression is not considered to be
+of type {\bf path} unless the path interpretation is the only~possibility.
+
+\bugonpage C176, line 7 from the bottom (07/09/20)
+
+\ninepoint\indent
+\quad {\bf if} |@#|$(\\{x\_})\colon\ \\{tx\_} \ \hbox{\bf else}\colon\
+ \\{fx\_}\  \hbox{\bf fi}$
+   :=\ \\{x\_}\thinspace; {\bf endfor}
+
+\bugonpage C180, line 3 from the bottom (06/24/20)
+
+\ninepoint\indent
+`$=$' or `$:=$' following {\bf let}.
+
+\bugonpage C187, line11 from the bottom (07/12/20)
+
+\ninepoint\indent\qquad
+\alt|substring|\thinspace\<pair expression>\thinspace|of|\thinspace
+ \<string primary>
+
+\bugonpage C189, line 14 (06/13/20)
+
+\ninepoint\noindent
+`|! |' and followed
+by~`|.|', followed by lines of context as in \MF's normal error\cutpar
+
+\bugonpage C200, line 12 from the bottom (08/27/20)
+
+\ninepoint\indent
+$y_1=y_2=\\{good.y}(.5[-d,h]+1.1\\{pt})$;
+
+\bugonpage C202, line 17 from the bottom (06/13/20)
+
+\ninepoint\noindent
+command,
+and it works only when the \\{penpos} angle is~0. If the \\{penpos} command
+is\cutpar
+
+\bugonpage C210, bottom eight lines, and top ten lines of page C211 (07/16/20)
+
+\ninepoint\noindent
+\beginsyntax
+<numeric atom>\is<numeric variable>\alt<numeric argument>
+ \alt<numeric token primary>
+ \alt<internal quantity>
+ \alt[normaldeviate]
+ \alt[(]<numeric expression>[)]
+ \alt[begingroup]<statement list><numeric expression>[endgroup]
+ \alt[length]<numeric primary>\alt[length]<pair primary>
+ \alt[length]<path primary>\alt[length]<string primary>
+ \alt[ASCII]<string primary>\alt[oct]<string primary>\alt[hex]<string primary>
+ \alt<pair part><pair primary>\alt<transform part><transform primary>
+ \alt[angle]<pair primary>
+ \alt[turningnumber]<path primary>\alt[totalweight]<picture primary>
+ \alt<numeric operator><numeric primary>
+ \alt[directiontime]<pair expression>[of]<path primary>
+<numeric token primary>\is<numeric token>[/]<numeric token>
+ \alt<numeric token not followed by %
+  `{\tt/}$\thinspace\langle$numeric token$\rangle$'\thinspace>
+<numeric primary>\is<numeric atom not followed by {[\char'133]<expression>[,]}>
+ \alt<numeric atom>[\char'133]<numeric expression>%
+   [,]<numeric expression>[\char'135]
+\endsyntax
+
+\bugonpage C214, line 6 becomes two lines (07/17/20)
+
+\ninepoint\noindent
+\beginsyntax
+<future pen primary>\is<future pen argument>
+ \alt[pencircle]
+\endsyntax
+
+\bugonpage C214, line 6 from the bottom (07/12/20)
+
+\ninepoint\noindent
+\beginsyntax
+ \alt[substring]<pair expression>[of]<string primary>
+\endsyntax
+
+\bugonpage C217, lines 20--25 (10/07/20)
+
+\ninepoint\noindent
+\beginsyntax
+<program>\is<statement list><non-title statement>[end]
+ \alt<statement list><non-title statement>[dump]
+<statement list>\is<empty>\alt<statement>[;]<statement list>
+<statement>\is<empty>\alt<title>
+ \alt<equation>\alt<assignment>\alt<declaration>
+ \alt<definition>\alt<compound>\alt<command>
+\endsyntax
+
+\bugonpage C219, line 25 (05/25/20)
+
+\ninepoint\noindent
+to see which of its subscripts and suffixes have occurred.
+For example, if you're\cutpar
+
+\bugonpage C224, lines 7--9 from the bottom (12/21/18)
+
+\tenpoint\indent
+|y4r=-0.9848thinn+259.00049|\par
+|x4r=-0.08682thinn+144|\par
+|y4=-0.4924thinn+259.00049|
+
+\bugonpage C226, lines 9 and 10 (11/01/20)
+
+\ninepoint\noindent
+This means that the preloaded base you have specified cannot be used,
+because it is corrupted or was prepared for a different version of
+\MF\kern-.03em.
+
+\bugonpage C228, line 27 (06/19/20)
+
+\ninepoint\indent
+|l.94 endfor|
+
+\bugonpage C228, line 4 from the bottom (07/12/20)
+
+\ninepoint\noindent
+might want to review now.) \
+You probably also have a |proof| mode diagram:
+
+\bugonpage C234, line 4 of answer 4.6 (07/20/20)
+
+\ninepoint\indent
+{\bf for} $k=1$ {\bf upto} 6: $z[k]'=.2[z[k],z_0]$; {\bf endfor}
+
+\bugonpage C241, line 2 (11/11/17)
+
+\ninepoint\indent
+|\mode=cheapo; input cheaplogo10|
+
+\bugonpage C242, line 11 of answer 13.7 (07/20/20)
+
+\ninepoint\indent
+{\bf for} $k=1$ {\bf upto} 4:
+ $z[k+4]=z[k]+({2\over3}s,{1\over3}s)$; \ {\bf endfor}
+
+\bugonpage C243, lines 7 and 8 (11/08/15)
+
+\ninepoint\indent
+\indent {\bf draw} subpath$(k,k+1)$ of \\{star}; {\bf cullit};\par\indent
+\indent {\bf undraw} subpath$(k+2,k+3)$ of \\{star} {\bf withpen}
+  \\{eraser}; {\bf cullit};
+
+\bugonpage C243, line 3 of answer 13.11 (06/17/20)
+
+\ninepoint\indent
+{\bf def overdraw expr} $c$ = {\bf begingroup save} \\{region};
+
+\bugonpage C243, lines 12--16 of answer 13.11 (05/24/20)
+
+\ninepoint\noindent
+\begindisplay
+{\bf beginchar}$(\hbox{\tt"M"},1.25\\{in}\0,.5\\{in}\0,0)$; \
+ {\bf pickup pencircle} scaled .4\\{pt};\cr
+$z_1=(20,-13)$; \ $z_2=(30,-6)$; \ $z_3=(20,1)$; \ $z_4=(4,-7)$;\cr
+\indent $z_5=(-12,-13)$; \ $z_6=(-24,-4)$; \ $z_7=(-15,6)$;\cr
+{\bf path} $M$; $M=(\\{origin}\dts
+ z_1\dts z_2\dts z_3\dts z_4\dts z_5\dts z_6\dts z_7\dts$\cr
+\indent$\\{origin}\dts -z_7\dts -z_6\dts -z_5\dts -z_4\dts
+  -z_3\dts -z_2\dts -z_1\dts\cycle)$\cr
+\enddisplay
+
+\bugonpage C246, line 2 of answer 14.13 (08/16/20)
+
+\ninepoint\noindent
+path $z_0\dashto z_1$ is equivalent to `$z_0\dts
+\controls1/3[z_0,z_1]\and2/3[z_0,z_1]\dts z_1$', and the\cutpar
+
+\bugonpage C247, line 1 of answer 15.5 (06/13/20)
+
+\ninepoint\noindent
+\quad{\bf 15.5.}\enspace
+{\bf beginchar}$(126,25u\0,\\{h\_height}\0+\\{border}\0,0)$; \
+|"Dangerous left bend"|;
+
+\bugonpage C247, replacement for answer 15.7 (07/21/20)
+
+\ninepoint\noindent
+\quad{\bf 15.7.}\enspace
+Replace lines 10 and 11 by
+\begindisplay
+{\bf pickup pencircle} scaled 3/4\\{pt} yscaled 1/3 rotated $-60$;\cr
+{\bf draw} ($z_1\ldots p$) transformed $t$;\cr
+{\bf addto} \\{currentpicture} {\bf also} \\{currentpicture}\cr
+\qquad rotatedaround$\bigl((.5w,.5h)$ yscaled \\{aspect\_ratio}$,-180\bigr)$;\cr
+\enddisplay
+
+\bugonpage C249, line 1 of answer 18.9 (08/02/20)
+
+\ninepoint\noindent
+\quad{\bf 18.9.}\enspace
+{\bf beginchar}\kern1pt(|"H"|$,13u\0,"ht"\0,0)$; \
+ {\bf pickup} \\{broad\_pen};
+
+\bugonpage C249, line 11 of answer 18.9 (08/02/20)
+
+\ninepoint\indent
+{\bf filldraw} $\\{bot\_serif\_edge}_4$
+
+\bugonpage C250, line 4 of answer 19.1 (04/19/20)
+
+\ninepoint\noindent
+because it saves a wee bit of time and because
+`;'\ often belongs before {\bf endfor}.
+
+\bugonpage C250, replacement for answer 19.3 (07/12/20)
+
+\ninepoint\noindent
+\quad{\bf 19.3.}\enspace
+Yes, if and only if $n-{1\over2}$ is an even integer.
+\ (Because ambiguous values are rounded upwards.)
+
+\bugonpage C251, replacement for answer 22.1 (07/12/20)
+
+\ninepoint\noindent
+\quad{\bf 22.1}\enspace
+(a) If and only if $n$ is an integer between 0 and 255.
+(b) If and only if $s$ is a string of length~1.
+
+\bugonpage C254, lines 10--13 from the bottom become five lines (06/26/20)
+
+\ninepoint\noindent
+\begintt
+? H
+I found no right delimiter to match a left one. So I've
+put one in, behind the scenes; this may fix the problem.
+|null
+?
+\endtt
+
+\bugonpage C260, the ``line'' after line 3 (06/14/20)
+
+\def\bb{$\,\left\{\vcenter\bgroup\halign\bgroup\hfil##\hfil\cr}
+\def\ee{\crcr\egroup\egroup\right\}\,$}
+\tenpoint\noindent
+\bb|font_size|\cr|font_slant|\cr|font_normal_space|\cr
+ |font_normal_stretch|\cr|font_normal_shrink|\cr|font_x_height|\cr
+ |font_quad|\cr|font_extra_space|\ee
+\bb|=|\cr\noalign{\kern-2pt}|:=|\cr\noalign{\kern-2pt}\<empty>\ee
+\<numeric$\0$>; \
+\bb|ligtable|\<ligs/kerns>\cr|charlist|\<codes>\cr|extensible|\<codes>\cr
+ |fontdimen|\<info>\cr|headerbyte|\<info>\ee;\kern-10pt
+
+\bugonpage C261, lines 16 and 17 from the bottom (06/14/20)
+
+\tenpoint\noindent
+\bb|proofrule|\cr|screenrule|\ee|(|\<pair>|,|\<pair>|)|; \
+|makegrid(|\<numerics>|)(|\<numerics>|)|;\smallskip\noindent
+|proofrulethickness| \<numeric$\0$>; \ |proofoffset| \<pair>.
+
+\bugonpage C266, lines 19 and 20 (07/04/20)
+
+\ninepoint\noindent
+You can say either `|incr|~|x|' or `|incr|~|(x)|', within
+an expression; but neither of them are valid statements by themselves.
+
+\bugonpage C269, line 11 (01/10/21)
+
+\ninepoint\indent
+|\smode="specmode"; mag=|\<magnification>|; input |\<font file name>
+
+\bugonpage C277, lines 15--19 (03/06/17)
+
+\ninepoint\noindent
+|def openit = openwindow currentwindow from origen    % and please correct|\par
+\noindent
+| to (screen_rows,screen_cols) at (-50,300) enddef;   % "(-50,300)" too|\par
+\noindent
+|def showit_ = display currentpicture inwindow currentwindow enddef;|\par
+\noindent
+|def showit = openit; let showit=showit_; showit enddef; % first time only|\par
+\kern3pt\hrule\medskip\noindent
+Plain \MF\ has several other terse commands
+similar to `{\bf openit}' and `{\bf showit}':
+
+\bugonpage C279, line 1 (11/11/17)
+
+\ninepoint\noindent
+| blacker:=.1;                   % make pens a teeny bit blacker|
+
+\bugonpage C289, line 20 (10/07/20)
+
+\ninepoint\indent
+|if {{(pair x) cand x>(0,0)}}: A else: B fi.|
+
+\bugonpage C291, line 18 (07/24/20)
+
+\ninepoint\indent
+| save u_; setu_ u; let switch_ = if; if false: enddef.|
+
+\bugonpage C292, line 10 from the bottom (10/23/20)
+
+\ninepoint\noindent
+be known by saying `{\bf if} known $(p-q)$: $p=q$ {\bf else}:~{\bf false fi}';
+transforms could be handled\cutpar
+
+\bugonpage C293, lines 13 and 14 from the bottom (10/27/20)
+
+\ninepoint\noindent
+$f(-1)$ is false! When $c\rightarrow0$, the quantity $a^3+b^3$
+approaches $-\infty$ when $c$~is positive, $+\infty$ when $c$~is
+negative. An attempt to `\\{solve} $f(1,-1)$' will divide by zero and
+come\cutpar
+
+\bugonpage C295, line 2 (07/04/20)
+
+\ninepoint\noindent
+`interpolate $(1,1)\dts(3,2)\dts(15,4)$ of~7' the approximate value 3.37.
+
+\bugonpage C299, bottom four lines of code become five (08/06/20)
+
+\ninepoint\noindent
+\begintt
+primarydef t Bernshtein nn = begingroup save r; r =
+ begingroup for n=nn downto 2:
+  for k=1 upto n-1: u_[[[k]]]:=t[[[u_[[[k]]],u_[[[k+1]]] ]]];
+  endfor endfor u_[[[1]]] endgroup; numeric u_[[[]]];
+ r endgroup enddef;
+\endtt
+
+\bugonpage C299, line 5 after the code becomes two lines (08/06/20)
+
+\ninepoint\noindent
+brackets are nested inside of brackets.
+However, the auxiliary variables `|u_[[[|$k$|]]]|' must not remain
+independent at the end.
+
+\bugonpage C305, lines 14--18 (07/08/20)
+
+\ninepoint\noindent
+|width_adj#:=0pt#;         % width adjustment for certain characters|\par
+\noindent
+|serif_fit#:=0pt#;         % extra sidebar near lowercase serifs|
+\vskip-3pt\noindent\qquad\vdots\par\noindent
+|low_asterisk:=false;      % should the asterisk be centered at the axis?|\par
+\noindent
+|math_fitting:=false;      % should math-mode spacing be used?|
+
+\bugonpage C317, line 21 becomes two lines (11/11/17)
+
+\ninepoint\noindent
+\beginsyntax
+<label>\is<code label>\alt<code>[::]\alt[\\\\:]
+<code label>\is\<code>[:]
+\endsyntax
+
+\bugonpage C318, lines 10--16 from the bottom (11/11/17)
+
+\ninepoint\noindent
+\beginsyntax
+ \alt<code label><labeled code>
+<extensible command>\is[extensible]<code label><four codes>
+<four codes>\is<code>[,]<code>[,]<code>[,]<code>
+\endsyntax
+Notice that a \<code label> can appear in a {\bf ligtable}, {\bf charlist}, or
+{\bf extensible} command.
+ These appearances are mutually exclusive: No code may be
+used more than once as a label. Thus, for example, a character with a
+ligature/kerning program cannot also be {\bf extensible}, nor can it be
+in a {\bf charlist} (except as the final item).
+
+\bugonpage C333, line 29 (10/25/19)
+
+\ninepoint\noindent
+|  "if charcode>0:currentpicture:=currentpicture scaled mg;fi;"|
+
+\bugonpage C333, bottom two lines become one (11/11/17)
+
+\ninepoint\noindent
+| if unknown scale: scale := max(1,round(pixels_per_inch/300)); fi|
+
+\bugonpage C339, line 3 (05/21/20)
+
+\ninepoint\noindent
+ing `\char'31', `\char'32',
+`\char'33', and~`\char'34') and the uppercase letters (including
+`\char'35', `\char'36', and~`\char'37') are\cutpar
+
+\bugonpage C341, line 14 from the bottom (11/11/17)
+
+\ninepoint\noindent
+prints the |\table| and the |\text|; ^|\bigtest| gives
+you the works, plus a mysterious word\cutpar
+
+\bugonpage C345 and following, selected amendments to the index (01/20/21)
+
+\eightpoint
+*|,| (comma), 57, 72, 73, 129, 155, 165--167, 171, 211--213, 218, 317, 318.\par
+`A', 10--11, 163, 164, 248, 302--303.\par
+\<addto command>, 118, $\underline{220}$.\par
+bell-shaped distribution, $\underline{183}$, 251.\par
+|black|, 270, 332--333.\par
+\<code> and \<code label>, $\underline{317}$.\par
+concatenation, of paths, {\it70}--{\it71}, {\it123}, 127--129, $\underline{130}$, 137, {\it245}, {\it266}.\par
+\quad of strings, {\it69}, 73, 84--85, $\underline{187}$, {\it278}, {\it286}, {\it312}.\par
+*|directiontime|, {\it135}, $\underline{\it136}$, 211, 245, 265, {\it298}.\par
+distance, 76, 84, {\sl see also\/} |length|.\par
+|dotprod|, {\it68}--{\it69}, 178, {\it238}, 265.\par
+efficiency, 39, 99, 116, 141, 144, 147, 228, 230, 234, 244, 264, 265, 277,  291, 297, 298.\par
+empty option in {\bf for\/} list, 171, $\underline{172}$, {\it299}.\par
+forbidden tokens, 173, $\underline{218}$--$\underline{219}$, 286.\par
+*|from|, $\underline{191}$, 220, {\it252}, {\it277}, {\it312}.\par
+Giotto di Bondone, 139.\par
+independent variables, $\underline{81}$--$\underline{83}$, 88, 224, 226, 299.\par
+|\init|, $\underline{337}$, 342.\par
+internal quantities, 54--55, 88, 218, 262, 265--266.\par
+*|inwindow|, $\underline{191}$, 220, {\it277}.\par
+\<keep or drop>, $\underline{118}$, 220.\par
+|labels|, {\it107}, $\underline{274}$, 327--328.\par
+*|length|, {\it66}, {\it69}, 72, 210, 238.\par
+*|ligtable|, {\it97}, {\it305}--{\it306}, $\underline{316}$--$\underline{317}$.\par
+loops, 169, 171--173, 179, 226--227, 259, 290--291, 299.\par
+`N', 184--185, 302--303.\par
+\<numeric token primary>, 72, $\underline{211}$.\par
+|o|, {\it23}, {\it34}, $\underline{93}$, 197, 200, 204, 240, 302.\par
+`O', 32--37, 161, 199, 302--303.\par
+overshoot, 23, 34, 93, 197, 200, 204, 302.\par
+|penpos|, {\it26}--{\it29}, 37, 80, {\it103}, {\it162}, $\underline{273}$, 310.\par
+pens, 21--29, 147--152, 297--298.\par
+*|rotated|, {\it21}--{\it22}, {\it25}, 27, 44, {\it68}, 73, {\it107}, {\it114}, {\it117}, $\underline{141}$, 213, {\it238}.\par
+|rule|, 274, 328.\par
+*|scaled|, {\it21}--{\it23}, {\it68}, 73, $\underline{141}$, 213, 244, 291.\par
+*|showstopping|, 211, 219, {\it227}, 230, {\it262}.\par
+string expressions, {\it69}, 187--189, 258, 286.\par
+\<suffix list>, $\underline{171}$, 236.\par
+sum, of vectors, 9, {\it68}.\par
+|test.mf|, 311--313.\par
+\TeX, 1, 34, 40, 91, 96, 98, 101--103, 315, 336--343, 361.\par
+text arguments, 219, 288--291, 299.\par
+|.tfm|, 39, 315--321, 333, 335.\par
+*|to|, $\underline{191}$, 220, {\it252}, {\it277}, {\it312}.\par
+undelimited suffix parameters, $\underline{167}$, 176, 266, 270.\par
+|undraw|, 113, 118, 120, {\it242}, $\underline{271}$.\par
+|unitsquare|, {\it116}, 123--124, 128, 132, 136, $\underline{263}$.\par
+*|unknown|, $\underline{170}$, 210.\par
+unknown quantities, nonnumeric, 84--85, 143.\par
+values, disappearance of, 56, 83, 88, 156--157, 177--178, 218, 239, 299.\par
+\<vardef heading>, 165, $\underline{178}$.\par
+*|xscaled|, {\it21}--{\it22}, {\it68}, 73, $\underline{141}$, 213, 244, 291.\par
+
+
+
+% Volume D
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Dv, line 16 (01/16/21)
+
+\tenpoint\noindent
+\kern12.5mm I believe that the final bug in \MF\ was discovered on January\cutpar
+
+\bugonpage Dv, bottom two lines (01/16/21)
+
+\eightpoint\noindent
+corporates all of those changes.
+I~now believe that the final bug was discovered on 03 July 2020
+and removed in version 2.71828182. % on 16 January 2021
+The finder's fee has converged to \$327.68.
+
+\hsize=35pc
+
+\bugonpage D2, last line of \S2 (01/15/21)
+
+\ninepoint\noindent
+$$\hbox{{\bf define} $\\{banner}\equiv\.{\char`\'This\]is\]METAFONT,\]Version\]2.71828182\char`\'}$\quad
+$\{\,$printed when \MF\ starts$\,\}$}$$
+
+\bugonpage D14, line 1 of \S30 (05/05/14)
+
+\tenpoint\noindent
+{\bf 20.} \quad The \\{input\_ln} function brings the next line of input from the specified
+file into available\cutpar
+
+\bugonpage D21, line 8 of \S47 (10/11/20)
+
+\ninepoint\noindent\quad
+$g$: \\{str\_number};\quad$\{\,$the string just created$\,\}$
+
+\bugonpage D27, lines 3 and 4 of \S61 (04/02/17)
+
+\tenpoint\noindent
+is not serious since we assume that this
+part of the program is system dependent.
+
+\bugonpage D28, line 7 (04/02/17)
+
+\ninepoint\noindent\quad
+{\bf var} $k$: $0\dts23$;\quad$\{\,$index to current digit; we assume
+ that $\vert n\vert<10^{23}\,\}$
+
+\bugonpage D32, line 2 of \S78 becomes two lines (06/27/20)
+
+\ninepoint\noindent\quad
+{\bf loop begin} \\{continue}: {\bf if} $\\{interaction}\ne\\{error\_stop\_mode}$
+  {\bf then return};\par
+\noindent\qquad
+\\{clear\_for\_error\_prompt}; \ \\{prompt\_input}(\.{"?\]"});
+
+\bugonpage D32, line 11 of \S79 (07/03/20)
+
+\ninepoint\noindent\quad
+\.{"E"}: {\bf if} $\\{file\_ptr}>0$ {\bf then if}
+ $\\{input\_stack}[\\{file\_ptr}].\\{name\_field}\ge256$ {\bf then}
+
+\bugonpage D33, line 5 of \S80 (07/03/20)
+
+\ninepoint\noindent\quad
+{\bf if} $\\{file\_ptr}>0$ {\bf then}\par
+\noindent\qquad
+{\bf if} $\\{input\_stack}[\\{file\_ptr}].\\{name\_field}\ge256$ {\bf then}
+\\{print}(\.{"E\]to\]edit\]your\]file."}
+
+\bugonpage D37, line 9 of \S93 (08/07/20)
+
+\ninepoint\noindent\qquad
+(\.{"Try\]to\]insert\]an\]instruction\]for\]me\](e.g.,\]%
+        \char`\`I\]show\]x;\char`\'),"})
+
+\bugonpage D82, line 2 from the bottom (09/19/19)
+
+\ninepoint\noindent\quad
+{\bf define} $\\{boundary\_char}=41$\quad$\{\,$the boundary character for ligatures$\,\}$
+
+\bugonpage D85, lines 3 and 4 of \S194 {(and \S194 actually moves to page D86)} (12/11/20)
+
+\tenpoint\noindent
+information, something special
+is needed. The program here simply assumes that suitable values appear in
+the global variables \\{sys\_time}, \\{sys\_day}, \\{sys\_month}, and
+\\{sys\_year} (which are initialized to noon on 4 July 1776,
+in case the implementor is careless).
+
+\bugonpage D85, the final six lines of \S194 {(and \S194 actually moves to page D86)} (12/11/20)
+
+\ninepoint\noindent
+{\bf procedure} \\{fix\_date\_and\_time};\par
+\noindent\quad{\bf begin}
+$\\{sys\_time}\gets12\ast60$; \
+$\\{sys\_day}\gets4$; \
+$\\{sys\_month}\gets7$; \
+$\\{sys\_year}\gets1776$;\quad
+$\{\,$self-evident truths$\,\}$\par
+\noindent\quad$\\{internal}[\\{time}]\gets\\{sys\_time}\ast\\{unity}$;\quad
+  $\{\,$minutes since midnight$\,\}$\par
+\noindent\quad$\\{internal}[\\{day}]\gets\\{sys\_day}\ast\\{unity}$;\quad$\{\,$day of the month$\,\}$\par
+\noindent\quad$\\{internal}[\\{month}]\gets\\{sys\_month}\ast\\{unity}$;\quad$\{\,$month of the year$\,\}$\par
+\noindent\quad$\\{internal}[\\{year}]\gets\\{sys\_year}\ast\\{unity}$;\quad$\{\,$Anno Domini$\,\}$\par
+\noindent\quad{\bf end};
+
+\bugonpage D86, replacement for \S196 (12/11/20)
+
+\tenpoint\noindent
+{\bf 196.}\quad Of course we had better declare a few more global variables,
+if the previous routines are going to work.
+\smallskip
+\ninepoint\noindent
+$\langle\,$Global variables {\sevenrm\kern.5em13}$\,\rangle+\equiv$\par
+\noindent\\{old\_setting}: $0\dts\\{max\_selector}$;\par
+\noindent\\{sys\_time}, \\{sys\_day}, \\{sys\_month}, \\{sys\_year}: \\{integer};
+\quad$\{\,$date and time supplied by external system$\,\}$
+
+\bugonpage D97, line 2 of \S221 (05/26/17)
+
+\tenpoint\noindent
+the definition of attribute nodes) that
+it is convenient to let $\\{info}(p)=0$ stand for `\.{[]}'.
+
+\goodbreak
+\bugonpage D148, line 7 (06/12/18)
+
+\tenpoint\noindent
+but the $\log n$ factor is buried in our
+implicit restriction on the maximum raster size.) The\cutpar
+
+\bugonpage D237, line 5 of \S513 (05/26/17)
+
+\ninepoint\noindent\quad
+{\bf for} $n\gets0$ {\bf to} $\\{n1}-\\{n0}-1$ {\bf do} $\\{env\_move}[n]\gets\\{mm0}$;
+
+\bugonpage D250, line 2 of \S534 (05/26/17)
+
+\tenpoint\noindent
+direction $\bigl(\\{right\_u}(p),\\{left\_v}(q)\bigr)$;
+and there's a line of length $\ge\\{delta}$ from vertex~$q$ to vertex~$r$,\cutpar
+
+\bugonpage D296, line 11 (06/23/20)
+
+\tenpoint\noindent
+\\{name} points to the \\{eqtb} address of the macro
+being expanded, if the current token list\cutpar
+
+\bugonpage D324, line 13 of \S713 (12/20/20)
+
+\ninepoint\noindent\qquad\quad
+\\{help2}(\.{"After\]\char`\`exitif\]<boolean\]expr>\char`\'\]I\]expect\]to\]see\]a\]%
+semicolon."})
+
+\bugonpage D326, line 5 from the bottom (06/23/20)
+
+\ninepoint\noindent\qquad\qquad
+$\{\,$invokes a user-defined sequence of commands$\,\}$
+
+\bugonpage D334, lines 1 and 2 of \S742 (10/25/20)
+
+\tenpoint\noindent
+{\bf 742.} \ Here is a procedure that ignores text until coming to an {\bf elseif},
+{\bf else}, or {\bf fi} at the current level of {\bf if}$\,\ldots\,${\bf fi}
+nesting. After it has acted, \\{cur\_mod} will indicate the token that
+was found.
+
+\bugonpage D339, line 4 of \S757 (06/16/20)
+
+\tenpoint\noindent\quad
+(A user who tries some shenanigan like `{\bf for} $\ldots$ {\bf let} {\bf endfor}'
+will be foiled by the \\{get\_symbol}\cutpar
+
+\bugonpage D351, lines 2--7 of \S536 become five lines (12/11/20)
+
+\ninepoint\noindent\quad
+{\bf begin} \\{wlog}(\\{banner});
+\\{slow\_print}(\\{format\_ident});
+\\{print}(\.{"\]\]"});
+\\{print\_int}(\\{sys\_day});
+\\{print\_char}(\.{"\]"});\par
+\noindent\quad
+$\\{months}\gets\.{\char`\'JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC\char`\'}$;\par
+\noindent\quad
+{\bf for} $k\gets3\ast\\{sys\_month}-2$ {\bf to} $3\ast\\{sys\_month}$
+{\bf do} \\{wlog}(\\{months}[$k$]);\par
+\noindent\quad
+\\{print\_char}(\.{"\]"});
+\\{print\_int}(\\{sys\_year});
+\\{print\_char}(\.{"\]"});
+\\{print\_two}(\\{sys\_time} {\bf div} 60);
+\\{print\_char}(\.{":"});\par
+\noindent\quad
+\\{print\_two}(\\{sys\_time} {\bf mod} 60);
+
+\bugonpage D352, line 2 of \S793 becomes two lines (10/29/20)
+
+\tenpoint\noindent
+command is being processed.
+Beware: For historic reasons, this code foolishly conserves a tiny bit
+of string pool space; but that can confuse the interactive `\.E' option.
+
+\bugonpage D352, line 5 from the bottom (10/29/20)
+
+\ninepoint\noindent
+{\bf if} $\\{name}=\\{str\_ptr}-1$ {\bf then}
+\ $\{\,$conserve string pool space (but see note above)$\,\}$
+
+\bugonpage D354, line 2 from the bottom (07/29/20)
+
+\tenpoint\noindent
+$\\{cur\_type}=\\{path\_type}$ means that \\{cur\_exp} points to the first
+node of
+a path; nobody else points\cutpar
+
+\bugonpage D469, lines 18--20 of \S1093 (09/19/19)
+
+\tenpoint\noindent
+so-called boundary character of this font;
+the value of \\{next\_char} need not lie between \\{bc} and~\\{ec}.
+If the very last instruction of the \\{lig\_kern} array has $\\{skip%
+\_byte}=255$,
+there is a special ligature/kerning program for a boundary character at the
+left, beginning at location $256\ast\\{op\_byte}+$\cutpar
+
+\bugonpage D469, line 30 of \S1093 (01/15/21)
+
+\tenpoint\noindent
+tional halt; no ligature or kerning command is performed.
+
+\bugonpage D471, lines 20 and 21 (08/07/20)
+
+\ninepoint\noindent
+\\{param}: {\bf array} $[1\dts\\{max\_font\_dimen}]$ {\bf of}
+\\{scaled};\quad$\{\,${\bf fontdimen} parameters$\,\}$\par\noindent
+\\{np}: $0\dts\\{max\_font\_dimen}$;\quad$\{\,$the largest {\bf fontdimen} parameter
+specified so far$\,\}$
+
+\bugonpage D474, line 2 from the bottom (08/07/20)
+
+\ninepoint\noindent\quad\qquad
+\\{help1}(\.{"A\]colon\]should\]follow\]a\]headerbyte\]or\]fontdimen\]location."});
+\\{back\_error};
+
+\bugonpage D508, line 3 of \S1189. (10/05/20)
+
+\tenpoint\noindent
+to be in the range $a\le x\le b$.
+System error messages should be suppressed when undumping.
+
+\bugonpage D516, line 6 (10/15/20)
+
+\tenpoint\noindent\quad
+If \\{final\_cleanup} is bypassed, this program doesn't bother to
+close the input files that may still be open.
+
+\bugonpage D519, line 17 (01/15/21)
+
+\ninepoint\noindent\quad
+\\{fix\_date\_and\_time};
+$\\{init\_randoms}(\\{sys\_time}+\\{sys\_day}*\\{unity})$;
+
+\bugonpage D520, line 18 of \S1212 becomes two lines (10/05/20)
+
+\ninepoint\noindent\quad
+{\bf begin} \\{clear\_terminal};\par
+\noindent\quad
+{\bf loop}
+
+\bugonpage D520, lines 11 and 12 from the bottom of \S1212
+  become three lines (04/02/17)
+
+\ninepoint\noindent\qquad\qquad
+{\bf begin goto} \\{breakpoint};\par
+\noindent\qquad\qquad\quad$\{\,$go to every declared label at least once$\,\}$\par
+\noindent\qquad\quad\\{breakpoint}: $m\gets0$;
+ \.{@\char`\{\char`\'BREAKPOINT\char`\'@\char`\}}
+
+\bugonpage D566, the bottom five lines (05/14/19)
+
+\tenpoint\noindent
+they occupy in a typical production system
+(executable code size for dark blocks, global data size for light blocks).
+In this way the chart indicates a total of about
+$8\times22=176${\ninerm K} bytes of memory, plus
+$8\times15=120${\ninerm K} for the
+dynamic memory region not shown explicitly. The dynamic memory
+is often considerably larger in practice, because it is desirable to
+accommodate large macro packages and large pictures.
+
+
+% volume E
+\hsize=29pc
+
+\newbox\shorthyf \setbox\shorthyf=\hbox{-\kern-.05em}
+\mathchardef\period=`\.
+{\catcode`\-=\active \global\def-{\copy\shorthyf\mkern3.9mu}
+ \catcode`\.=\active \global\def.{\period\mkern3mu}}
+\def\8#1{\mathrel{\mathcode`\.="8000 \mathcode`\-="8000
+  #1\unkern}} % `..' and `--'
+
+
+\bye
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.three b/Master/texmf-dist/doc/generic/knuth-errata/errata.three
new file mode 100644
index 00000000000..d4a0afaccd8
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.three
@@ -0,0 +1,1898 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\cutpar{{\parfillskip=0pt\par}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\noindent This is a list of all corrections made to {\sl Computers \&
+Typesetting}, Volumes A--E\null, between the date of publication
+(May, 1986) and 15~June 1987.
+It also includes corrections made to
+the softcover version of {\sl The \TeX book}, beginning with the
+sixth printing (January 1986); these are the same as corrections to
+Volume~A\null. Corrections to the softcover version of {\sl The
+\slMF\kern1ptbook\/} are the same as corrections to Volume~C\null.
+% volume A
+\bugonpage A7, fourth line from the bottom (6/28/86)
+
+\tenpoint\line{%
+since control sequences of the second kind always have exactly one
+symbol after}
+
+\bugonpage A35, second-last line (1/31/87)
+
+\rightline{\eightssi He may run who reads.}
+\smallskip
+\rightline{\eightss--- HABAKKUK 2\thinspace:\thinspace2 (c.~600 B.C.)}
+\smallskip
+\rightline{\eightssi He that runs may read.}
+
+\bugonpage A43, lines 8--9 (8/23/86)
+
+\tenpoint\noindent
+of Appendix B\null, which defines |%| to be a special kind of symbol so that you
+can use it for comments, defines the control sequence |\%| to mean
+a percent sign.
+
+\bugonpage A45, lines 10--13 (8/23/86)
+
+\ninepoint\noindent
+\TeX\ adds~64. Hence
+code 127 can be typed |^^?|, and
+the dangerous bend sign can be obtained by saying
+|{\manual^^?}|. However, you must change the category code of character
+127 before using it, since this character ordinarily has category~15
+(^{invalid}); say, e.g., |\catcode`\^^?=12|.
+The |^^| notation is different from |\char|, because |^^|\cutpar
+
+\bugonpage A76, line 7 (8/23/86)
+
+\ninepoint
+\noindent
+and extra space; for example, these quantities are
+$3.33333\pt$, $1.66666\pt$, $1.11111\pt$,\cutpar
+
+\bugonpage A83, bottom line (5/19/87)
+
+\tenpoint\noindent[This line should be flush right.]
+
+\bugonpage A111, 7th-last line, right-hand column (2/15/87)
+
+\ninepoint
+if $b=10000$ and $-10000<p<10000$ and $q<10000$;
+
+\bugonpage A117, second-last line (6/10/87)
+
+\eightpoint
+marks; sometimes also |$\|\||$| ($\Vert$).
+You can say, e.g., `|\footnote\dag{...}|'.
+
+\bugonpage A124, lines 6--11 (2/26/87)
+
+\begingroup \def\n{\thinspace$n$}
+\ninepoint\noindent
+of insertion; an additional `|\penalty-10000|' item is assumed
+to be present at the end of the vertical list, to ensure that a legal
+breakpoint exists.) \ Let $u$ be the natural height plus depth of that
+least-cost box, and let $r$ be the penalty associated with the optimum
+breakpoint.  Decrease $g$ by~$uf$, and increase $q$ by~$r$. \ (If
+|\tracingpages||=1|, the log file should now get a cryptic message that says
+`|% split|\n\ |to| $v$|,|$u$ |p=|$r$'. For~example,
+\begintt
+% split254 to 180.2,175.3 p=100
+\endtt
+\endgroup
+
+\bugonpage A158, lines 6--8 (2/20/87)
+
+\ninepoint\noindent the
+second atom, which has subscript~$i$; the superscripts are empty except for the
+last atom, whose superscript is~$\overline{n+1}$. This superscript is
+itself a math list consisting of one atom, whose nucleus is~$n+1$; and that
+nucleus is a math list consisting of three atoms.
+
+\bugonpage A171, line 20 (1/26/86)
+
+\ninepoint\line{%
+will be surrounded by more space than there would be
+if that subformula were enclosed}
+
+\bugonpage A176, line 1 (8/23/86)
+
+\ninepoint
+You can insert `|\noalign||{|$\langle$vertical mode
+material$\rangle$|}|' just after any \kern-1pt|\cr| within\cutpar
+
+\bugonpage A248, line 17 (6/17/86)
+
+\ninepoint
+`|&|' or `|\span|' or `|\cr|', it needs some way to decide which
+alignment is involved.\cutpar
+
+\bugonpage A249, line 20 (6/17/86)
+
+\ninepoint\noindent
+line (see Chapter~8).
+If you don't want a~|\cr| at the end of a certain line,
+just type\cutpar
+
+\bugonpage A276, line 19 (1/27/86)
+
+\ninepoint\vskip-3pt
+\beginsyntax
+  \alt^|\font|<control sequence><equals><file name><at clause>
+  \alt<global assignment>
+\endsyntax
+[The bottom line of p.~276 will now move to the top of p.~277.]
+
+\bugonpage A277, lines 31--32 (1/27/86)
+
+\ninepoint
+\beginsyntax
+<font assignment>\is^|\fontdimen|<number><font><equals><dimen>
+\endsyntax
+
+\bugonpage A286, sixth-last line (4/28/87)
+
+\ninepoint\noindent
+|\sfcode| table as described in Chapter~12; characters numbered 128
+to~255 set the\cutpar
+
+\bugonpage A287, line 19 (2/15/87)
+
+\ninepoint
+\textindent{$\bull$}|\-|.\enskip
+This ``discretionary hyphen'' command is defined in Appendix H.
+
+\bugonpage A292, lines 9--10 (2/15/87)
+
+\ninepoint
+\textindent{$\bull$}|\-|.\enskip
+This command is usually equivalent to `|\discretionary{-}{}{}|'; the `|-|' is
+therefore interpreted as a ^{hyphen}, not as a minus sign.
+\ (See Appendix~H.)
+
+\bugonpage A308, lines 25--26 (6/1/87)
+
+\ninepoint\indent
+|\def\appendroman#1#2#3{\edef#1{\csname|\parbreak
+|      \expandafter\gobble\string#2\romannumeral#3\endcsname}}|
+
+\bugonpage A312, lines 10--14 (8/23/86)
+
+\ninepoint
+\ansno12.11: The interline glue will be zero, and the natural height is
+$1+1-3+2=1\pt$ (because the depth of\/ |\box2| isn't included in the natural
+height); so the glue will ultimately become |\vskip-1pt| when it's set.
+Thus, |\box3| is $3\pt$ high, $2\pt$ deep, $4\pt$ wide. Its reference
+point coincides with that of\/ |\box2|; to get to the reference point
+of\/ |\box1| you go up $2\pt$ and right $3\pt$.
+
+\bugonpage A312, line 21 (8/23/86)
+
+\ninepoint\noindent
+up $4\pt$ to get to the upper left corner of
+|\box4|; then down $-1.6\pt$, i.e., up $1.6\pt$, to\cutpar
+
+\bugonpage A319, line 20 (31/3/87)
+
+\ninepoint\noindent
+make ordinary periods act like |\cdot| symbols: Just define
+|\mathcode`.| to be |"0201|,\cutpar
+
+\bugonpage A328, lines 18--19 (5/14/87)
+
+\ninepoint\noindent
+not performed
+while the expansion is taking place, and the control sequences following
+|\def| are expanded; so the result is an infinite string
+\begintt
+A\def A\def A\def A\def A\def A\def A\def A\def A...
+\endtt
+
+\bugonpage A329, lines 14--15 (8/23/86)
+
+\ninepoint
+\ansno20.5: The |##| feature is indispensable when the replacement text of
+a definition contains other definitions. For example, consider
+
+\bugonpage A356, lines 6--7 (1/30/87)
+
+\ninepoint\noindent
+|  \spaceskip=.3333em \xspaceskip=.5em\relax}|\hfil\break
+|\def\ttraggedright{\tt\rightskip=0pt plus2em\relax}|
+
+\bugonpage A356, line 33 (6/1/87)
+
+\ninepoint\noindent
+|    \vbox to.2ex{\hbox{\char'26}\vss}\hidewidth}}|
+
+\bugonpage A357, tenth-last line (10/13/86)
+
+\ninepoint\noindent
+|\let\sp=^ \let\sb=_        {\catcode`\_=\active \global\let_=\_}|
+
+\bugonpage A357, third-last and second-last lines (2/17/87)
+
+\ninepoint\noindent
+|\def\pr@m@s{\ifx'\next\let\nxt\pr@@@s \else\ifx^\next\let\nxt\pr@@@t|%
+\hfil\break\strut
+|  \else\let\nxt\egroup\fi\fi \nxt}|
+
+\bugonpage A364, fifth-last line (1/30/87)
+
+\ninepoint\noindent
+|\def\fmtname{plain}\def\fmtversion{2.3} % identifies the current format|
+
+\bugonpage A368, bottom line (2/26/86)
+
+\ninepoint
+\line{that includes the symbols
+{\tentex\char'30},~{\tentex\char1}, {\tentex\char'32}, {\tentex\char'34},
+and~{\tentex\char'35}, and he finds that this makes it much more}
+
+\bugonpage A396, line 13 (8/23/86)
+
+\ninepoint
+|  \hyphenpenalty=10000 \exhyphenpenalty=10000|
+
+\bugonpage A414, line 10 (3/4/86)
+
+\ninepoint\noindent
+|\font\titlefont=cmssdc10 at 40pt   % titles in chapter openings|
+
+\bugonpage A427, line 7 (2/23/86)
+
+\ninepoint\noindent
+the author's book
+{\sl Computer Modern Typefaces}.)
+
+\bugonpage A428, lines 18--20 (6/15/87)
+
+\tenpoint\noindent
+The first eight of these all have essentially the same layout;
+but |cmr5| needs no ligatures, and many of the symbols of |cmti10|
+have different shapes.
+For example, the ^{ampersand} becomes an `^{E.T.}', and the
+^{dollar} changes to ^{pound} ^{sterling}:
+
+\bugonpage A434, lines 25--28 (8/17/86)
+
+\tenpoint\noindent
+from |\nu|~($\nu$). Similarly,
+|\varsigma|~($\varsigma$) should not be confused with |\zeta|~($\zeta$).
+It turns out that |\varsigma| and |\upsilon| are almost never used in
+math formulas; they are included in plain \TeX\ primarily because they are
+sometimes needed in short Greek citations (cf.~Appendix~J).
+
+\bugonpage A447, line 32 (6/1/87)
+
+\ninepoint\noindent
+ters
+also affect mathematical typesetting:
+dimension parameters
+ \hbox{|\delimitershortfall|}\cutpar
+
+\bugonpage A455, new paragraph to follow line 9 (2/15/87)
+
+\begingroup
+\hyphenpenalty=-1000 \pretolerance=-1 \tolerance=1000
+\doublehyphendemerits=-100000 \finalhyphendemerits=-100000
+\ddanger The control sequence ^|\-| is equivalent to
+|\discretionary{\char|$\,h$|}{}{}|, where $h$ is the
+^|\hyphenchar| of the current font, provided that $h$ lies
+between 0 and~255. Otherwise |\-| is equivalent to |\discretionary{}{}{}|.
+
+\endgroup % end the special hyphenation conventions
+
+\bugonpage A457, left column, fifth-last line (2/17/87)
+
+\eightpoint\indent\qquad 155, 201, {\it 305}, 324, $\underline{357}$, 394--395;
+
+\bugonpage A458, left column, line 6 (2/15/87)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\-} (discretionary hyphen), 95, 283, 287,\par
+\indent\qquad 292, $\underline{455}$.
+
+\bugonpage A458, left column, near the bottom (5/19/87)
+
+\eightpoint {\tt!} (exclamation point), 51,
+{\it 72}, 73, 75, {\it 169}.
+\nobreak\medskip\noindent[This saves a line that otherwise would make
+the index too long on page 481!]
+
+\bugonpage A458, right column, line 10 (11/27/86)
+
+\eightpoint {\tt\char`\~}
+(tilde), 38, 51, 343, $\underline{353}$; {\sl see also\/} ties.
+
+\bugonpage A458, right column (6/14/87)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\accent} (general accent), 9, 54, 86, 283, $\underline{286}$.
+
+\bugonpage A461, entry for boxes (3/16/87)
+
+\eightpoint boxes, 63--67, 77--83, 221--229.
+
+\bugonpage A461, entry for {\tt\char`\\centering} (1/28/86)
+
+\eightpoint {\tt\char`\\centering}, $\underline{347}$, 348, 362.
+
+\bugonpage A462, entry for \<code assignment> (1/27/86)
+
+\eightpoint \<code assignment>, $\underline{277}$.
+
+\bugonpage A464, left column, line 3 (2/15/87)
+
+\eightpoint
+discretionary hyphens, 28, 95--96, 453, $\underline{455}$.
+
+\bugonpage A465, right column, line 8 (5/3/87)
+
+\eightpoint
+expansion of expandable tokens, 212--216, 238,
+
+\bugonpage A466, entry for {\tt\char`\\font}, second line (1/27/86)
+
+\eightpoint \indent\qquad 271, $\underline{276}$.
+
+\bugonpage A466, new entry (2/3/87)
+
+\eightpoint \indent\<fontdef token>, $\underline{271}$.
+
+\bugonpage A467, entry for {\tt\char`\\hideskip} (1/28/86)
+
+\eightpoint {\tt\char`\\hideskip}, $\underline{347}$, 348, 354.
+
+\bugonpage A468, left column line 2 (2/15/87)
+
+\eightpoint\indent\qquad 351, 395, {\it 414}, 454, 455.
+
+\bugonpage A470, entry for {\tt manfnt} (1/15/86)
+
+\eightpoint {\tt manfnt}, 44, 408, 414.
+
+\bugonpage A471, entry for {\tt\char`\\medbreak} (10/13/86)
+
+\eightpoint {\tt\char`\\medbreak}, 111, 113, $\underline{353}$,
+ {\it355}, {\it419}, {\it422}.
+
+\bugonpage A471, entry for {\tt\char`\\moveright} (2/27/87)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\moveright}, 80--81, {\it 221}, $\underline{282}$.
+
+\bugonpage A471, entry for Mozart, second line (3/19/86)
+
+\eightpoint \indent\qquad Gottlieb (= Theophilus = Amadeus), 409.
+
+\bugonpage A472, the entry for {\tt\char`\\not} (2/12/87)
+
+\eightpoint\noindent
+[The overprinting here is intentional, since {\tt\char`\\not} is a
+character of width zero. More than a dozen people have reported this
+as an error, but it is not!]
+
+\bugonpage A477, entry for {\tt\char`\\span} (5/3/87)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\span}, 215, 238, $\underline{243}$, {\it244}, $\underline{245}$,
+248, 249,\par
+\indent\qquad 282, {\it330}, 385.
+
+\bugonpage A479, entry for ties, second line (11/27/86)
+
+\eightpoint \indent\qquad {\it173}, 353, {\it404}.
+
+\bugonpage A480, changes to various entries (6/14/87)
+
+\eightpoint
+\newbox\astbox \setbox\astbox=\hbox to0pt{\hss\lower1pt\hbox{*}}
+\def\prim#1{\par\indent\copy\astbox{\tt\char`\\#1}}
+\prim{underline}, {\it130--131}, 141, 291, $\underline{443}$.
+\prim{unhbox}, 120, 283, $\underline{285}$, {\it354}, {\it356}, {\it361},
+ {\it399}.
+\prim{unhcopy}, 120, 283, $\underline{285}$, {\it353}.
+\prim{unkern}, $\underline{280}$.
+\prim{unpenalty}, $\underline{280}$.
+\prim{unskip}, 222--223, $\underline{280}$, 286, {\it313}, {\it392},
+ {\it418--419}.
+\prim{unvbox}, 120, 254, $\underline{282}$, 286, {\it354}, {\it361},
+ {\it363}, {\it364}, {\it392}, {\it399}, {\it417}.
+\prim{unvcopy}, 120, $\underline{282}$, 286, {\it361}.
+\prim{vadjust}, 95, 105, 109, 110, 117, 259, $\underline{281}$, 393, 454.
+\prim{valign}, 249, 283, $\underline{285}$--$\underline{286}$, 302,
+ {\it335}, {\it397}.
+\prim{vcenter}, 150--151, 159, 170, 193, 222, 242,
+\prim{vfil}, 71, $\underline{72}$, 111, 256, 281, 286, 417.
+\prim{vfill}, 24, 25, 71, $\underline{72}$, 256--257, 281, 286.
+\prim{vfilneg}, $\underline{72}$, 111, 281, 286.\par
+|\voidb@x|, $\underline{347}$, 348.
+
+\bugonpage A481, left column (6/14/87)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt\char`\\vss}, 71, $\underline{72}$, {\it 255}, 281, 286.
+
+% volume B
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\buginvol B, in general (7/28/86)
+
+\tenpoint\noindent
+[A number of entries were mistakenly omitted from the mini-indexes
+on the right-hand pages. Here is a combined list of all the missing
+items; you can mount it inside the back cover, say, as a secondary mini-index
+when the first one fails\dots\ ]
+
+\nobreak\medskip
+\setbox0=\vbox{\eightpoint \hsize=11pc \catcode`\_=\active \let_=\_
+  \rightskip=0pt plus 100pt minus 10pt
+  \pretolerance 10000
+  \hyphenpenalty 10000 \exhyphenpenalty 10000
+  \noindent\vbox to1pt{}\par % 1pt = \topskip - \ninept
+  \def\&#1{\hbox{\bf#1\/}} % boldface type for reserved words
+  \obeylines
+  \def\makeref #1 #2 #3#4
+   {\nn=#2 \hangindent=1em \noindent\\{#1}%
+    \if#3:: \else\unhcopy\eqbox \fi#4, \S\number\nn.\par}
+  \makeref active_base 222 =$1$
+  \makeref aux 213 =macro
+  \makeref begin_name 515 :\&{procedure}
+  \makeref big_switch 1030 =$60$
+  \makeref choice_node 689 =$15$
+  \makeref cur_boundary 271 :$0\to \\{save\_size}$
+  \makeref cur_c 724 :\\{quarterword}
+  \makeref cur_group 271 :\\{group\_code}
+  \makeref cur_i 724 :\\{four\_quarters}
+  \makeref cur_level 271 :\\{quarterword}
+  \makeref do_extension 1348 :\&{procedure}
+  \makeref dvi_buf 595 :\&{array}
+  \makeref dvi_gone 595 :\\{integer}
+  \makeref dvi_limit 595 :\\{dvi\_index}
+  \makeref dvi_offset 595 :\\{integer}
+  \makeref dvi_ptr 595 :\\{dvi\_index}
+  \makeref end_graf 1096 :\&{procedure}
+  \makeref error 82 :\&{procedure}
+  \makeref error_stop_mode 73 =$3$
+  \makeref font_base 12 =$0$
+  \makeref font_info 549 :\&{array}
+  \makeref get_token 365 :\&{procedure}
+  \makeref glue_base 222 =$2626$
+  \makeref half_buf 595 :\\{dvi\_index}
+  \makeref handle_right_brace 1068 :\&{procedure}
+  \makeref hash_base 222 =$258$
+  \makeref head 213 =macro
+  \makeref hyf_distance 921 :\&{array}
+  \makeref hyf_next 921 :\&{array}
+  \makeref hyf_num 921 :\&{array}
+  \makeref index 302 =macro
+  \makeref inf 448 :\\{boolean}
+  \makeref init_col 788 :\&{procedure}
+  \makeref init_span 787 :\&{procedure}
+  \makeref input_ln 31 :\&{function}
+  \makeref interaction 73 :$0\to 3$
+  \makeref limit 302 =macro
+  \makeref line_width 830 :\\{scaled}
+  \makeref macro_call 389 :\&{procedure}
+  \makeref main_control 1030 :\&{procedure}
+  \makeref mem 116 :\&{array}
+  \makeref mem_bot 12 =$0$
+  \makeref mem_end 118 :\\{pointer}
+  \makeref mem_top 12 =macro
+  \makeref mlist_to_hlist 726 :\&{procedure}
+  \makeref mode 213 =macro
+  \makeref mode_line 213 =macro
+  \makeref more_name 516 :\&{function}
+  \makeref mu 448 :\\{boolean}
+  \makeref name 302 =macro
+  \makeref nest 213 :\&{array}
+  \makeref off_save 1064 :\&{procedure}
+  \makeref open_log_file 534 :\&{procedure}
+  \makeref output_active 989 :\\{boolean}
+  \makeref p 498 :\\{pointer}
+  \makeref param_stack 308 :\&{array}
+  \makeref pool_file 50 :\\{alpha\_file}
+  \makeref pool_ptr 39 :\\{pool\_pointer}
+  \makeref prefixed_command 1211 :\&{procedure}
+  \makeref prev_depth 213 =macro
+  \makeref prev_graf 213 =macro
+  \makeref prev_prev_r 830 :\\{pointer}
+  \makeref print_err 73 =macro
+  \makeref r 960 :\\{trie\_pointer}
+  \makeref reconstitute 906 :\&{function}
+  \makeref resume_after_display 1200 :\&{procedure}
+  \makeref save_ptr 271 :$0\to \\{save\_size}$
+  \makeref save_stack 271 :\&{array}
+  \makeref scan_dimen 448 :\&{procedure}
+  \makeref scan_math 1151 :\&{procedure}
+  \makeref short_display 174 :\&{procedure}
+  \makeref show_node_list 182 :\&{procedure}
+  \makeref start 302 =macro
+  \makeref state 302 =macro
+  \makeref str_pool 39 :\&{packed}\ \&{array}
+  \makeref str_ptr 39 :\\{str\_number}
+  \makeref str_start 39 :\&{array}
+  \makeref tail 213 =macro
+  \makeref trap_zero_glue 1229 :\&{procedure}
+  \makeref trie 921 :\&{array}
+  \makeref trie_char 921 =macro
+  \makeref trie_link 921 =macro
+  \makeref trie_op 921 =macro
+  \makeref vlist_out 629 :\&{procedure}
+  \makeref write_loc 1345 :\\{pointer}
+  }
+\hbox{\nsize=\ht0 \advance\nsize-\topskip
+  \divide\nsize by 3 \divide\nsize by\ninept
+  \multiply\nsize by\ninept \advance\nsize\topskip
+  \vsplit0 to\nsize \kern1pc
+  \msize=\ht0 \advance\msize-\topskip
+  \divide\msize by 2 \divide\msize by\ninept
+  \multiply\msize by\ninept \advance\msize\topskip
+  \vbox to\nsize{\vsplit0 to\msize\vss}\kern1pc
+  \vbox to\nsize{\box0\vss}}
+
+\buginvol B, in general (4/6/87)
+
+\tenpoint\noindent[The percent signs in all the comments (for example,
+on pages 7 and 50) are in the wrong font! Change `{\tt\%}' to `\%'.]
+
+\bugonpage Bvi, bottom line, and top line of next page (10/12/86)
+
+{\hsize=29pc
+\tenpoint\noindent
+puter Science Report 1097 (Stanford, California, April 1986), 146~pp.
+\ {\it The {\sltt WEB} programs for four utility programs that are
+often used with \TeX: {\sltt POOLtype}, {\sltt TFtoPL},
+{\sltt PLtoTF}, and {\sltt DVItype}.}
+\par}
+
+\bugonpage B2, line 32 (4/22/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]2.2\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B7, new line after line 25 (1/28/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf if} $\\{max\_in\_open}\ge128$ {\bf then} $\\{bad}\gets6$;
+
+\bugonpage B13, first three lines (4/7/87)
+
+\tenpoint\noindent
+The `\\{name}' parameter, which is of type `{\bf packed array
+$[\langle\\{any}\rangle]$ of \\{char}}', stands for the name of
+the external file that is being opened for input or output.
+Blank spaces that might appear in \\{name} are ignored.
+
+\bugonpage B14, line 30 (4/7/87)
+
+\tenpoint\noindent
+{\bf 31.\quad}%
+The \\{input\_ln} function brings the next line of input from the specified
+file into available\cutpar
+
+\bugonpage B18, line 30 (5/22/86)
+
+\ninepoint\noindent
+\\{str\_ptr}: \\{str\_number};\quad
+$\{\,$number of the current string being created$\,\}$
+
+\bugonpage B21, first line of mini-index, right column (6/14/87)
+
+\eightpoint
+\indent\\{pool\_name}\unhcopy\eqbox|"string"|, \S11.
+
+\bugonpage B34, lines 5--6 (6/14/87)
+
+\tenpoint\noindent
+to delete a token, and/or if some fatal error
+occurs while \TeX\ is trying to fix a non-fatal one. But such recursion
+is never more than two levels deep.
+
+\bugonpage B55, lines 12--13 (4/21/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf if} $r=p$ {\bf then if} $\\{rlink}(p)\ne p$ {\bf then}
+  $\langle\,$Allocate entire node $p$ and {\bf goto} \\{found}%
+  {\sevenrm\kern.5em129}$\,\rangle$;
+
+\bugonpage B57, lines 25--28 (6/14/87)
+
+\tenpoint\noindent
+The first of these has $\\{font}=\\{font\_base}$, and its \\{link}
+points to the second;
+the second identifies the font and the character dimensions.
+The saving feature about oriental characters is that most of them have
+the same box dimensions. The \\{character} field of the first \\{char\_node}
+is a ``\\{charext}'' that distinguishes between graphic symbols whose
+dimensions are identical for typesetting purposes. (See the \MF\ manual.)
+Such an extension of \TeX\ would not be difficult; further details are
+left to the reader.
+
+\bugonpage B58, second line of section 136 (7/23/86)
+
+\tenpoint\noindent
+the values corresponding to `|\hbox{}|'. The \\{subtype} field is set to
+\\{min\_quarterword}, since that's\cutpar
+
+\bugonpage B66, lines 2--8 (4/21/87)
+
+\tenpoint\noindent
+location is
+more efficient than dynamic allocation when we can get away with it. For
+example, locations \\{mem\_bot} to $\\{mem\_bot}+3$ are always used to store the
+specification for glue that is `\hbox{\tt 0pt plus 0pt minus 0pt}'. The
+following macro definitions accomplish the static allocation by giving
+symbolic names to the fixed positions. Static variable-size nodes appear
+in locations \\{mem\_bot} through \\{lo\_mem\_stat\_max}, and static
+single-word nodes appear in locations \\{hi\_mem\_stat\_min} through
+\\{mem\_top}, inclusive. It is harmless to let \\{lig\_trick} and
+\\{garbage} share the same location of \\{mem}.
+
+\bugonpage B67, line 23 (4/13/87)
+
+\ninepoint\noindent\hskip30pt
+$\{\,$previous \\{mem\_end}, \\{lo\_mem\_max}, and \\{hi\_mem\_min}$\,\}$
+
+\bugonpage B71, line 17 (4/15/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin while} $p>\\{mem\_min}$ {\bf do}
+
+\smallskip\eightpoint\noindent[Now \\{null} can be removed from the mini-index.]
+
+\bugonpage B74, line 24 (4/15/87)
+
+\ninepoint\noindent
+{\bf procedure} \\{show\_node\_list}($p\;{:}\;\\{integer}$);\quad
+$\{\,$prints a node list symbolically$\,\}$
+
+\bugonpage B74, line 33 (4/15/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf while} $p>\\{mem\_min}$ {\bf do}
+
+\bugonpage B84, line 12 (2/15/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{relax}=0$\quad$\{\,$do nothing ( {\tt\char`\\relax} )$\,\}$
+
+\bugonpage B86, third line of section 210 (8/23/86)
+
+\tenpoint\noindent
+that their special nature is easily discernible.
+The ``expandable'' commands come first.
+
+\bugonpage B88, line 23 (5/22/86)
+
+\ninepoint\noindent
+{\bf procedure\/}\  $\\{print\_mode}(m:\\{integer})$;\quad
+$\{\,$prints the mode represented by $m\,\}$
+
+\bugonpage B93, lines 3--4 (8/17/86)
+
+{\tenpoint\parindent=1em
+In the first region we have 128 equivalents for ``active characters'' that
+act as control sequences, followed by 128 equivalents for single-character
+control sequences.
+\par}
+
+\bugonpage B130, ninth-last line (5/7/87)
+
+\tenpoint\noindent
+This variable has six possible values:
+
+\bugonpage B151, line 9 (4/22/87)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin if} $(\\{end\_line\_char}<0)\lor(\\{end\_line\_char}>127)$
+ {\bf then} \\{incr}(\\{limit});\par\noindent\hskip20pt
+{\bf if} $\\{limit}=\\{start}$ {\bf then}\quad
+ $\{\,$previous line was empty$\,\}$
+
+\bugonpage B160, lines 17--20 (7/28/86)
+
+\tenpoint\noindent
+{\bf 389.\quad}%
+After parameter scanning is complete, the parameters are moved to the
+\\{param\_stack}. Then the macro body is fed to the scanner; in other words,
+\\{macro\_call} places the defined text of the control sequence at the
+top of\/ \TeX's input stack, so that \\{get\_next} will proceed to read it
+next.
+
+\bugonpage B200, top line (5/5/87)
+
+\tenpoint\noindent{\bf 495.\quad}%
+ When we begin to process a new {\tt\char`\\if}, we set
+$\\{if\_limit}\gets\\{if\_code}$; then
+if\/ {\tt\char`\\or} or {\tt\char`\\else} or {\tt\char`\\fi}\cutpar
+
+\bugonpage B217, lines 15--16 (6/14/87)
+
+\tenpoint\noindent
+|DVI| format.
+
+\bugonpage B224, lines 4--7 of section 560 (10/22/86)
+
+\tenpoint\noindent
+name and area strings \\{nom} and \\{aire}, and the
+``at'' size~$s$. If $s$~is negative, it's the negative of a scale factor
+to be applied to the design size; $s=-1000$ is the normal case.
+Otherwise $s$ will be substituted for the design size; in this
+case, $s$ must be positive and less than $2048\rm\,pt$
+(i.e., it must be less than $2^{27}$ when considered as an integer).
+
+\bugonpage B224, second-last line (4/28/87)
+
+\ninepoint\noindent
+\\{done}: {\bf if} \\{file\_opened} {\bf then} \\{b\_close}(\\{tfm\_file});\par
+\noindent\hskip10pt $\\{read\_font\_info}\gets g$;
+
+\bugonpage B255, mini-index at the bottom (4/15/87)
+
+\eightpoint
+$\\{mag}=\rm macro$, \S236.
+
+\bugonpage B257, lines 11--13 (6/14/87)
+
+\ninepoint
+\noindent\hskip20pt{\bf if} $c\ge\\{qi}(128)$ {\bf then}
+ \\{dvi\_out}(\\{set1});\par
+\noindent\hskip20pt\\{dvi\_out}(\\{qo}($c$));
+
+\bugonpage B260, lines 7--8 (4/15/87)
+
+\tenpoint\noindent\hskip10pt
+In the case of \\{c\_leaders} (centered leaders), we want to increase \\{cur\_h}
+by half of the excess space not occupied by the leaders; and in the
+case of \\{x\_leaders} (expanded leaders) we increase\cutpar
+
+\bugonpage B267, mini-index at the bottom (4/15/87)
+
+\eightpoint
+\\{cur\_s}: \\{integer}, \S616.
+$\\{mag}=\rm macro$, \S236.
+$\\{pop}=142$, \S586.
+
+\bugonpage B271, line 10 (8/23/86)
+
+\tenpoint\noindent
+which will be ignored in the calculations
+because it is a highly negative number.
+
+\bugonpage B285, lines 23 and 24 (5/4/87)
+
+\tenpoint\noindent
+the current string would be `{\tt.\char`\^.\char`\_/}'
+if $p$ points to the \\{ord\_noad} for $x$ in the (ridiculous) formula
+`{\tt\char`\$\char`\\sqrt\char`\{a\char`\^\char`\{\char`\\mathinner\char`\{%
+b\char`\_\char`\{c\char`\\over x+y\char`\}\char`\}\char`\}\char`\}\char`\$}'.
+
+\bugonpage B296, lines 3--5 (5/8/87)
+
+\tenpoint\noindent
+box~$b$ and
+changes it so that the new box is centered in a box of width~$w$.
+The centering is done by putting {\tt\char`\\hss} glue at the left and right
+of the list inside $b$, then packaging the new box; thus, the
+actual box might not really be centered, if it already contains
+infinite glue.
+
+\bugonpage B346, line 19 (5/19/87)
+
+\ninepoint\noindent
+\\{pass\_number}: \\{halfword};\quad
+$\{\,$the number of passive nodes allocated on this pass$\,\}$
+
+\bugonpage B350, lines 36 and 37 (1/28/87)
+
+\ninepoint\noindent
+$v$: \\{pointer};\quad
+$\{\,$points to a glue specification or a node ahead of \\{cur\_p}$\,\}$
+\par\noindent
+$t$: \\{integer};\quad
+$\{\,$node count, if \\{cur\_p} is a discretionary node$\,\}$
+
+\bugonpage B353, lines 8--22 (1/28/87)
+
+\ninepoint
+\noindent\hskip10pt$s\gets\\{cur\_p}$;\par
+\noindent\hskip10pt{\bf  if} $\\{break\_type}>\\{unhyphenated}$ {\bf then}
+ {\bf if} $\\{cur\_p}\ne\\{null}$ {\bf then}\par
+\noindent\hskip30pt$\langle\,$Compute the discretionary
+ \\{break\_width} values{\sevenrm\kern.5em840}$\,\rangle$;\par
+\noindent\hskip10pt{\bf  while} $s\ne\\{null}$ {\bf do}\par
+\noindent\hskip30pt\vdots\hskip30pt [as before, but indented one less notch]\par
+\noindent\hskip10pt{\bf end};
+
+\bugonpage B354, line 6 (1/28/87)
+
+\tenpoint\noindent
+will be the background plus $l_1$, so the length from \\{cur\_p} to \\{cur\_p}
+should be $\gamma+l_0+l_1-l$,
+minus the length of nodes that will be discarded after the discretionary break.
+
+\bugonpage B354, lines 12--18 (1/28/87)
+
+\ninepoint
+\noindent\hskip10pt{\bf begin} $t\gets\\{replace\_count}(\\{cur\_p})$;\kern5pt
+  $v\gets\\{cur\_p}$;\kern5pt $s\gets\\{post\_break}(\\{cur\_p})$;\par
+\noindent\hskip10pt{\bf while} $t>0$ {\bf do}\par
+\noindent\hskip20pt{\bf begin} $\\{decr}(t)$;\kern5pt
+ $v\gets\\{link}(v)$;\kern5pt
+ $\langle\,$Subtract the width of node $v$ from \\{break\_width}%
+ {\sevenrm\kern.5em841}$\,\rangle$;\par
+\noindent\hskip20pt{\bf end};\par
+\noindent\hskip10pt{\bf while} $s\ne\\{null}$ {\bf do}\par
+\noindent\hskip20pt{\bf  begin} $\langle\,$Add the width of
+  node $s$ to \\{break\_width} and increase $t$, unless it's
+  discardable{\sevenrm\kern.5em842}$\,\rangle$;\par
+
+\bugonpage B354, new line after line 21 (1/28/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf if} $t=0$ {\bf then} $s\gets\\{link}(v)$;\quad
+ $\{\,$more nodes may also be discardable after the break$\,\}$
+
+\bugonpage B354, lines 26--34 (1/28/87)
+
+\ninepoint\noindent
+[Change `$s$' to `$v$' throughout this section (8 times).]
+
+\bugonpage B354, line 9 from the bottom (1/28/87)
+
+\tenpoint\noindent{\bf 842.\quad}%
+\ninepoint$\langle\,$Add the width of
+  node $s$ to \\{break\_width} and increase $t$, unless it's
+  discardable{\sevenrm\kern.5em842}$\,\rangle\equiv$
+
+\bugonpage B355, lines 1--3 (1/28/87)
+
+\ninepoint
+\noindent\hskip20pt$\\{hlist\_node},\\{vlist\_node},\\{rule\_node}$:
+ $\\{break\_width}[1]\gets\\{break\_width}[1]+\\{width}(s)$;\par
+\noindent\hskip20pt\\{kern\_node}: {\bf if} $(t=0)\land
+ (\\{subtype}(s)\ne\\{acc\_kern})$ {\bf then}
+  $t\gets-1$\quad$\{\,$discardable$\,\}$\par
+\noindent\hskip30pt{\bf  else} $\\{break\_width}[1]\gets
+ \\{break\_width}[1]+\\{width}(s)$;\par
+\noindent\hskip20pt{\bf  othercases}
+ \\{confusion}({\tt\char'42 disc2\char'42})\par
+\noindent\hskip20pt{\bf endcases};\par
+\noindent\hskip10pt$\\{incr}(t)$
+
+\bugonpage B355, patches to mini-index at bottom (1/28/87)
+
+\eightpoint
+$\\{acc\_kern}=2$, \S155.\par
+$\\{incr}=\rm macro$, \S16.\par
+$t$: \\{integer}, \S830.\par
+$v$: \\{pointer}, \S830.
+
+\bugonpage B372, lines 12--14 (1/28/87)
+
+\ninepoint
+\noindent\hskip40pt$\langle\,$Change discretionary to compulsory
+ and set $\\{disc\_break}\gets\\{true}${\sevenrm\kern.5em882}$\,\rangle$\par
+\noindent\hskip30pt{\bf else if\/} $(\\{type}(q)=\\{math\_node})\lor
+ (\\{type}(q)=\\{kern\_node})$ {\bf then} $\\{width}(q)\gets0$;
+
+\bugonpage B380, fifth-last line (5/7/87)
+
+\begingroup\tenpoint\noindent\def\!{\kern-1pt}\def\.#1{\hbox{\tt#1}}
+\.b and \.c, the two patterns with and without hyphenation are
+$\.a\,\.b\,\.-\,\.{c\!d}\,\.{e\!f}$ and $\.a\,\.{b\!c}\,\.{d\!e}\,\.f$.
+Thus the\cutpar\endgroup
+
+\bugonpage B386, lines 2--4 (5/21/87)
+
+\tenpoint\noindent
+hyphenation,
+\TeX\ first looks to see if it is in the user's exception dictionary. If not,
+hyphens are inserted based on patterns that appear within the given word,
+using an algorithm due to Frank~M. Liang.
+
+\bugonpage B397, line 28 (5/21/87)
+
+\tenpoint\noindent
+$h=z-c$. It follows that location \\{trie\_max} will
+never be occupied in \\{trie}, and we will have\cutpar
+
+\bugonpage B415, the mini-index (4/6/87)
+
+\eightpoint\noindent[Delete the spurious entry for `$c$'.]
+
+\bugonpage B419, mini-index entry for \\{c} (4/6/87)
+
+\eightpoint $c$: \\{integer}, \S994.
+
+\bugonpage B422, line 24 (8/23/86)
+
+\ninepoint\noindent
+\hskip20pt\\{prev\_p}: \\{pointer};\quad
+$\{\,$predecessor of $p\,\}$
+
+\bugonpage B435, line 16 (10/12/86)
+
+\ninepoint\noindent
+\hskip20pt$\\{width}(p)\gets\\{font\_info}[k].\\{sc}$;\quad
+$\{\,$that's \\{space}$(f)\,\}$\par\noindent
+\hskip20pt$\\{stretch}(p)\gets\\{font\_info}[k+1].\\{sc}$;\quad
+$\{\,$and \\{space\_stretch}$(f)\,\}$\par\noindent
+\hskip20pt$\\{shrink}(p)\gets\\{font\_info}[k+2].\\{sc}$;\quad
+$\{\,$and \\{space\_shrink}$(f)\,\}$\par
+\smallskip\eightpoint\noindent
+[And the mini-index gets three new entries:
+$\\{space}=macro$, \S558.
+$\\{space\_shrink}=macro$, \S558.
+$\\{space\_stretch}=macro$, \S558.]
+
+\bugonpage B495, lines 18 and 19 (2/15/87)
+
+\ninepoint\noindent
+[delete these lines, since the cases cannot occur]
+
+\bugonpage B510, line 8 (12/15/86)
+
+\ninepoint\noindent\hskip30pt
+({\tt"Pretend\]that\]you're\]Hercule\]Poirot:\]Examine\]all\]clues,"})
+
+\bugonpage B527, new line to follow line 13 (6/17/86)
+
+{\tenpoint\parindent=1em
+This program doesn't bother to close the input files that may still be open.
+\par}
+
+\bugonpage B534, fourth-last line (5/4/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{write\_stream}(\hbox{\tt\char`\#})\equiv\\{info}(
+ \hbox{\tt\char`\#}+1)$\quad $\{\,$stream number (0 to 17)$\,\}$
+
+\bugonpage B544, left column (1/28/87)
+
+\eightpoint
+\leftline{\\{acc\_kern}:\quad$\underline{155}$, 191, 837, 842, 879, 1125.}
+
+\bugonpage B546, entry for \\{c} (4/6/87)
+
+\eightpoint\noindent[Add a reference to section $\underline{994}$.]
+
+\bugonpage B547, left column (4/7/87)
+
+\eightpoint
+\leftline{\\{char}:\quad 19, 26--27, 520, 534.}
+
+\bugonpage B547, left column (6/14/87)
+
+\eightpoint
+\leftline{Chinese characters:\quad 134, 585.}
+
+\bugonpage B553, entry for \\{font\_base} (6/14/87)
+
+\eightpoint\noindent[Insert a reference to section 134.]
+
+\bugonpage B555, right column, new entry (10/25/86)
+
+\eightpoint
+\leftline{{\tt Huge page...},\quad 641.}
+
+\bugonpage B556, entry for \\{incr} (1/28/87)
+
+\eightpoint\noindent[Add a reference to section 842.]
+
+\bugonpage B557, entry for \\{is\_char\_node} (1/28/87)
+
+\eightpoint\noindent[Delete the reference to section 881.]
+
+\bugonpage B557, right column (6/14/87)
+
+\eightpoint
+\leftline{Japanese characters:\quad 134, 585.}
+
+\bugonpage B560, right column (1/28/87)
+
+\eightpoint
+\leftline{\\{max\_in\_open}:\quad$\underline{11}$, 14, 304, 328.}
+
+\bugonpage B561, left column, line 10 (4/15/87)
+
+\eightpoint
+\leftline{\qquad 169--172, 174, 178, 182, 1249, 1312, 1334.}
+
+\bugonpage B561, left column (5/1/87)
+
+\eightpoint
+\leftline{{\tt Missing font identifier}:\quad 577.}
+
+\bugonpage B563, left column, line 2 (4/15/87)
+
+\eightpoint
+\leftline{\qquad 136, 145, 149--154, 164, 168--169, 175--176, 182,}
+
+\bugonpage B563, right column (6/14/87)
+
+\eightpoint
+\leftline{oriental characters:\quad 134, 585.}
+
+\bugonpage B569, right column, in appropriate places (10/12/86)
+
+\eightpoint
+\leftline{\\{space}:\quad 547, $\underline{558}$, 752, 755, 1042.}
+\leftline{\\{space\_shrink}:\quad 547, $\underline{558}$, 1042.}
+\leftline{\\{space\_stretch}:\quad 547, $\underline{558}$, 1042.}
+
+\bugonpage B570, third-last line (1/28/87)
+
+\eightpoint\noindent\qquad
+ 786, 795, 809, 819--820, 822, 837, 842--844, 866,
+
+\bugonpage B571, right column (10/25/86)
+
+\eightpoint
+\leftline{{\tt The following...deleted},\quad 641, 992, 1121.}
+
+\bugonpage B571, right column (4/7/87)
+
+\eightpoint
+\leftline{\\{text\_char}:\quad $\underline{19}$, 20, 25, 47.}
+
+\bugonpage B573, right column (5/1/87)
+
+\eightpoint\noindent
+[Delete the entry for `{\tt Undefined font code}'.]
+
+\bugonpage B576, line 2 (1/28/87)
+
+\ninepoint\noindent
+$\langle\,$Add the width of
+  node $s$ to \\{break\_width} and increase $t$, unless it's
+  discardable{\sevenrm\kern.5em842}$\,\rangle$\par
+\noindent\qquad {\eightpoint Used in section 840.}
+
+\bugonpage B591, line 6 from the bottom (1/28/87)
+
+\ninepoint\noindent
+ $\langle\,$Subtract the width of node $v$ from \\{break\_width}%
+ {\sevenrm\kern.5em841}$\,\rangle$\quad
+ {\eightpoint Used in section 840.}
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+
+\bugonpage C14, top two lines (3/16/87)
+
+\danger The recursive midpoint rule for curve-drawing was discovered in 1959
+by Paul de Casteljau, who showed that the curve could be described
+algebraically by the remarkably simple formula
+
+\bugonpage C54, sixth-last to fourth-last lines (10/13/86)
+
+\ninepoint Jonathan H. Quick (a student) used `|a.plus1|' as the name
+of a variable at the beginning of his program; later he said `|let|
+|plus=+|'. How could he refer to the variable `|a.plus1|' after that?
+
+\bugonpage C76, line 14 (10/13/86)
+
+\tenpoint
+\newdimen\longesteq
+\setbox0=\hbox{\indent$z_{12}-z_{11}=z_{14}-z_{13}$\quad}
+\longesteq=\wd0
+\noindent\hbox to \longesteq{\indent
+  $x_4=w-.01\\{in}$\hfil}%
+Point 4 should be one-hundredth of an inch inside\cutpar
+
+\bugonpage C103, line 12 (10/12/86)
+
+\tenpoint
+$\\{ht}\0=\\{body\_height}\0$; \ $.5[\\{ht}\0,-\\{dp}\0]=\\{axis}\0$;
+
+\bugonpage C105, line 13 (10/13/86)
+
+\ninepoint
+The vertical line just to the right of the italic left parenthesis
+shows the italic\cutpar
+
+\bugonpage C113, lines 20--27 (8/23/86)
+
+{\catcode`\@=\active
+\def@#1@{\begingroup\def\_{\kern.04em
+    \vbox{\hrule width.3em height .6pt}\kern.08em}%
+  \ifmmode\mathop{\bf#1}\else\hbox{\bf#1\/}\fi\endgroup}
+\danger The command `@erase@ @fill@ $c$' is an abbreviation for
+`@cullit@; @unfill@~$c$; @cullit@'; this zeros out the pixel values inside
+the cyclic path~$c$, and sets other pixel values to~1 if they were positive
+before erasing took place. \ (It works because the initial @cullit@ makes
+all the values 0 or~1, then the @unfill@ changes the values inside~$c$
+to 0 or negative. The final @cullit@ gets rid of the negative values,
+so that they won't detract from future filling and drawing.) \ You can
+also use `@draw@', `@filldraw@', or `@drawdot@' with `@erase@'; for example,
+`@erase@ @draw@~$p$' is an abbreviation for `@cullit@; @undraw@~$p$;
+@cullit@', which uses the currently-picked-up pen as if it were an
+eraser applied to path~$p$.
+
+}
+
+\bugonpage C124, line 9 (6/17/86)
+
+\eightpoint
+\noindent\hskip1.8in
+$\\{branch}_2=\\{flex}((30,570),(10,590),(-1,616))$
+
+\bugonpage C130, 3rd-last line (9/25/86)
+
+\ninepoint\noindent
+{\sl Geometry\/ \bf 1} (1986), 123--140]: Given a sequence
+
+\bugonpage C144, sixth line of the program (8/23/86)
+
+\ninepoint\noindent\hbox to\parindent{\hfil\sevenrm6\ \ \ }%
+$y_2=.1h$; \ $\\{top}\,y_3=.4h$;
+
+\bugonpage C148, the line before the illustration (11/27/86)
+
+\ninepoint\noindent
+are polygons with 32 and 40 sides, respectively:
+
+\smallskip\noindent
+[New illustrations are needed here, since \MF\ version 1.3 improves
+the accuracy of pen polygons.]
+
+\bugonpage C149, 7th line after the illustration (10/24/86)
+
+\ninepoint
+\line{$(200,y+100\pm\alpha)$, where
+$\alpha=\sqrt5/4\approx0.559$. If we digitize these outlines and fill the}
+
+\bugonpage C178, second-last line (8/23/86)
+
+\ninepoint\noindent
+(If $t_3=t_1$~transum~$t_2$, then
+$z$~transformed~$t_3=z$~transformed~$t_1+z$~transformed~$t_2$,\cutpar
+
+\bugonpage C198, fifth-last and fourth-last lines (10/13/86)
+
+\ninepoint\vskip-3pt
+\begindisplay
+$\\{top}\,y_2={\rm round}(\\{top}\,\beta)$.
+\enddisplay
+Such operations occur frequently in practice, so plain \MF\ provides
+convenient\cutpar
+
+\bugonpage C212, lines 9--11 from the bottom (8/23/86)
+
+\ninepoint
+\qquad
+ \alt\[point]\<numeric expression>\[of]\<path primary>\continuerule
+ \alt\[precontrol]\<numeric expression>\[of]\<path primary>\continuerule
+ \alt\[postcontrol]\<numeric expression>\[of]\<path primary>
+
+\bugonpage C233, lines 13--14 (2/15/87)
+
+\ninepoint\noindent
+one column of white
+pixels, if the character is $2a$ pixels wide, because the right edge of
+black pixels is specified here to have the $x$~coordinate $2a-1$.
+
+\bugonpage C247, lines 23--25 (11/27/86)
+
+\ninepoint
+\ansno 16.2:
+ `{\bf pencircle} scaled 1.06060' is the diamond but
+`{\bf pencircle} scaled 1.06061' is~the square. \ (This assumes that
+$\\{fillin}=0$. If, for example, $\\{fillin}=.1$, the change doesn't
+occur until the diameter is 1.20204.) \ The next change is at diameter
+1.5, which\cutpar
+
+\bugonpage C262, lines 1--4 (7/28/86)
+
+\ninepoint
+When we come to macros whose use has not yet been explained---for
+example, somehow |softjoin| and |stop| never made it
+into Chapters 1 through~27---we shall consider them from a user's
+viewpoint. But most of the comments that follow are addressed to a
+potential base-file designer.
+
+\bugonpage C266, line 16 (8/17/86)
+
+\ninepoint\noindent
+variables; they have the side effect of changing the variable's value.
+
+\bugonpage C276, line 26 (6/23/86)
+
+\ninepoint
+\noindent
+| if charic<>0: r((w+charic*hppp,h.o_),(w+charic*hppp,.5h.o_)); fi|
+
+\bugonpage C286, lines 24--26 (10/13/86)
+
+\ninepoint\noindent
+but \MF\ won't let you. And even if this had worked, it wouldn't have
+solved the problem; it would simply have put |ENDFOR| into the
+replacement text of |ast|, because expansion is inhibited when the
+replacement text is being read.
+
+\bugonpage C290, line 1 (8/23/86)
+
+\ninepoint  \noindent{\it 2.\enspace Fortuitous loops.\enspace}%
+The `^{max}' and `^{min}' macros in Appendix~B make use of the fact\cutpar
+
+\bugonpage C298, third-last line (8/23/86)
+
+\ninepoint
+$t[\,u_1,\ldots,u_n]\;=\;t\bigl[t[u_1,\ldots,u_{n-1}],t[u_2,\ldots,u_n]\,\bigr]$
+
+\bugonpage C304, 14th-last line (2/15/87)
+
+\ninepoint\noindent
+[replace this `|\smallskip|' by a |\smallskip| between lines!]
+
+\bugonpage C307, fifth-last line (12/7/86)
+
+\ninepoint
+{\def\_{\kern.04em
+    \vbox{\hrule width.3em height .6pt}\kern.08em}%
+\bf adjust\_fit}(\<left sidebearing adjustment>,\thinspace
+  \<right sidebearing adjustment>);
+
+\bugonpage C312, line 34 (10/12/86)
+
+\ninepoint\noindent
+|params[2] = "sans_params";      fontname[2] = "cmssbx10";|
+
+\bugonpage C316, lines 19--21 (8/17/86)
+
+\ninepoint\noindent
+example,
+`|(some| |charht| |values| |had| |to| |be| |adjusted| |by| |as| |much|
+|as| |0.12pt)|' means that~you had too many different nonzero heights, but
+\MF\ found a way to reduce the number to at most~15 by changing some of
+them; none of them had to be\cutpar
+
+\bugonpage C319, line 3 (8/23/86)
+
+\ninepoint\noindent
+specified by saying, e.g.,
+
+\bugonpage C321, line 6 (7/28/86)
+
+\ninepoint\noindent
+|  special "identifier " & font_identifier_;|
+
+\bugonpage C334, line 2 (6/23/86)
+
+\ninepoint\noindent
+|  currentpicture := currentpicture shifted-(1,1); pix := currentpicture;|
+
+\bugonpage C339, tenth-last line (2/4/87)
+
+\ninepoint\noindent
+|  Jackie K\=aren {\L}au\.ra Mar{\'\i}a N\H{a}ta{\l}{\u\i}e {\O}ctave|
+
+\bugonpage C343, second-last line (8/23/86)
+
+\rightline{\eightssi
+the precise needs of a precise but limited intellectual goal.}
+
+\bugonpage C346, 2nd line of entry for `{\tt;}' (1/12/87)
+
+\eightpoint
+\qquad 217, 223--224, 263, 312.
+
+\bugonpage C348, line 6 (6/17/86)
+
+\eightpoint
+concatenation, of paths, {\eightit 70--71}, {\eightit 123}, 127,
+
+\bugonpage C348, just before `debugging' (3/16/87)
+
+\eightpoint
+de Casteljau, Paul de Faget, 14.
+
+\bugonpage C348, right column (3/16/87)
+
+\eightpoint\noindent
+[The entry for `|define_whole_vertical_blacker_pixels|' should be moved up
+before the entry for `|define_whole_vertical_pixels|'.]
+
+\bugonpage C352, left column (6/1/87)
+
+\eightpoint\indent\hbox to0pt{\hss\lower1pt\hbox{*}}%
+{\tt kern}, {\it 97}, {\it 316}, $\underline{317}$.
+
+\bugonpage C352, right column (3/8/87)
+
+\eightpoint\noindent
+[The entry for `|lowres|' belongs before the entry for `|lowres_fix|'.]
+
+\bugonpage C353, left column (3/8/87)
+
+\eightpoint\noindent
+[The entries for `|mode|' and `\<mode command>' belong before the entry
+for `|mode_def|'.]
+
+\bugonpage C353, entry for {\tt mode\char`\_def} (8/17/86)
+
+\eightpoint
+{\tt mode\char`\_def}, 94, 189, $\underline{\smash{\hbox{\it 270}}}$,
+{\it 278--279}.
+
+\bugonpage C355, right column (4/15/86)
+
+\eightpoint\noindent
+[The entry for `{\tt rulepen}' belongs before the entry for `rules'.]
+
+\bugonpage C355, right column (8/5/86)
+
+\eightpoint
+{\tt screenstrokes}, 191, $\underline{277}$.
+
+\bugonpage C355, 2nd line of entry for `semicolons' (1/12/87)
+
+\eightpoint
+\qquad 217, 223--224, 263, 312.
+
+\bugonpage C356, full names for the Stanfords (4/10/86)
+
+\eightpoint
+Stanford, Amasa Leland, 340.
+
+Stanford, Jane Elizabeth Lathrop, 340.
+
+% Volume D
+\hsize=35pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\buginvol D, in general (7/28/86)
+
+\tenpoint\noindent
+[A number of entries were mistakenly omitted from the mini-indexes
+on the right-hand pages. Here is a combined list of all the missing
+items; you can mount it inside the back cover, say, as a secondary mini-index
+when the first one fails\dots\ ]
+
+\nobreak\medskip
+\setbox0=\vbox{\eightpoint \hsize=11pc \catcode`\_=\active \let_=\_
+  \rightskip=0pt plus 100pt minus 10pt
+  \pretolerance 10000
+  \hyphenpenalty 10000 \exhyphenpenalty 10000
+  \noindent\vbox to1pt{}\par % 1pt = \topskip - \ninept
+  \def\&#1{\hbox{\bf#1\/}} % boldface type for reserved words
+  \obeylines
+  \def\makeref #1 #2 #3#4
+   {\nn=#2 \hangindent=1em \noindent\\{#1}%
+    \if#3:: \else\unhcopy\eqbox \fi#4, \S\number\nn.\par}
+  \makeref add_or_subtract 930 :\&{procedure}
+  \makeref after 427 :\&{array}
+  \makeref arg_list 720 :\\{pointer}
+  \makeref b 580 :\\{pixel\_color}
+  \makeref bad_exp 824 :\&{procedure}
+  \makeref before 427 :\&{array}
+  \makeref begin_name 770 :\&{procedure}
+  \makeref bilin1 968 :\&{procedure}
+  \makeref binary_mac 863 :\&{procedure}
+  \makeref blank_rectangle 567 :\&{procedure}
+  \makeref boc_c 1162 :\\{integer}
+  \makeref boc_p 1162 :\\{integer}
+  \makeref cf 298 :\\{fraction}
+  \makeref clockwise 453 :\\{boolean}
+  \makeref ct 298 :\\{fraction}
+  \makeref cubic_intersection 556 :\&{procedure}
+  \makeref cur_pen 403 :\\{pointer}
+  \makeref cur_rounding_ptr 427 :$0\to \\{max\_wiggle}$
+  \makeref cur_spec 403 :\\{pointer}
+  \makeref cur_x 389 :\\{scaled}
+  \makeref cur_y 389 :\\{scaled}
+  \makeref dely 557 :\\{integer}
+  \makeref dep_finish 935 :\&{procedure}
+  \makeref dep_list 587 =macro
+  \makeref dimen_head 1125 :\&{array}
+  \makeref dx 495 :\\{integer}
+  \makeref dy 495 :\\{integer}
+  \makeref d1 464 :$0\to 1$
+  \makeref end_name 772 :\&{procedure}
+  \makeref eqtb 201 :\&{array}
+  \makeref error_stop_mode 68 =$3$
+  \makeref firm_up_the_line 682 :\&{procedure}
+  \makeref get_next 667 :\&{procedure}
+  \makeref gf_buf 1152 :\&{array}
+  \makeref gf_offset 1152 :\\{integer}
+  \makeref gf_ptr 1152 :\\{gf\_index}
+  \makeref halfword 156 =$\\{min\_halfword}\to \\{max\_halfword}$
+  \makeref hash 201 :\&{array}
+  \makeref index 629 =macro
+  \makeref input_ln 30 :\&{function}
+  \makeref interaction 68 :$0\to 3$
+  \makeref j 357 :$0\to \\{move\_size}$
+  \makeref known_pair 872 :\&{procedure}
+  \makeref limit 629 =macro
+  \makeref m_spread 357 :\\{integer}
+  \makeref materialize_pen 865 :\&{procedure}
+  \makeref max_allowed 403 :\\{scaled}
+  \makeref max_c 813 :\&{array}
+  \makeref max_link 813 :\&{array}
+  \makeref max_tfm_dimen 1130 :\\{scaled}
+  \makeref mem_top 12 =macro
+  \makeref mem 159 :\&{array}
+  \makeref memory_word 156 =\&{record}
+  \makeref more_name 771 :\&{function}
+  \makeref m1 464 :\\{integer}
+  \makeref n 580 :\\{screen\_col}
+  \makeref n_sin_cos 145 :\&{procedure}
+  \makeref name 629 =macro
+  \makeref negate_dep_list 904 :\&{procedure}
+  \makeref new_knot 871 :\&{function}
+  \makeref node_to_round 427 :\&{array}
+  \makeref n1 464 :\\{integer}
+  \makeref octant_dir 395 :\&{array}
+  \makeref o1 453 :\\{small\_number}
+  \makeref o2 453 :\\{small\_number}
+  \makeref paint_row 568 :\&{procedure}
+  \makeref param 1096 :\&{array}
+  \makeref param_stack 633 :\&{array}
+  \makeref path_length 916 :\&{function}
+  \makeref perturbation 1119 :\\{scaled}
+  \makeref phi 542 :\\{angle}
+  \makeref pool_ptr 38 :\\{pool\_pointer}
+  \makeref post_head 843 :\\{pointer}
+  \makeref pre_head 843 :\\{pointer}
+  \makeref print_err 68 =macro
+  \makeref print_macro_name 722 :\&{procedure}
+  \makeref quarterword 156 =$0\to 255$
+  \makeref recycle_value 809 :\&{procedure}
+  \makeref row_transition 579 :\\{trans\_spec}
+  \makeref scan_text_arg 730 :\&{procedure}
+  \makeref scroll_mode 68 =$2$
+  \makeref set_controls 299 :\&{procedure}
+  \makeref sf 298 :\\{fraction}
+  \makeref show_context 635 :\&{procedure}
+  \makeref sorted 325 =macro
+  \makeref st 298 :\\{fraction}
+  \makeref start 629 =macro
+  \makeref start_sym 1077 :\\{halfword}
+  \makeref str_pool 38 :\&{packed}\ \&{array}
+  \makeref str_ptr 38 :\\{str\_number}
+  \makeref str_start 38 :\&{array}
+  \makeref take_part 910 :\&{procedure}
+  \makeref tfm_changed 1130 :\\{integer}
+  \makeref tol 557 :\\{integer}
+  \makeref tt 843 :\\{small\_number}
+  \makeref tx 954 :\\{scaled}
+  \makeref txx 954 :\\{scaled}
+  \makeref txy 954 :\\{scaled}
+  \makeref ty 954 :\\{scaled}
+  \makeref tyx 954 :\\{scaled}
+  \makeref tyy 954 :\\{scaled}
+  \makeref unsorted 325 =macro
+  \makeref uv 557 :$0\to \\{bistack\_size}$
+  \makeref xy 557 :$0\to \\{bistack\_size}$
+  \makeref x1 542 :\\{scaled}
+  \makeref x2 542 :\\{scaled}
+  \makeref x3 542 :\\{scaled}
+  \makeref y1 542 :\\{scaled}
+  \makeref y2 542 :\\{scaled}
+  \makeref y3 542 :\\{scaled}
+  }
+\hbox{\nsize=\ht0 \advance\nsize-\topskip
+  \divide\nsize by 3 \divide\nsize by\ninept
+  \multiply\nsize by\ninept \advance\nsize\topskip
+  \vsplit0 to\nsize \kern1pc
+  \msize=\ht0 \advance\msize-\topskip
+  \divide\msize by 2 \divide\msize by\ninept
+  \multiply\msize by\ninept \advance\msize\topskip
+  \vbox to\nsize{\vsplit0 to\msize\vss}\kern1pc
+  \vbox to\nsize{\box0\vss}}
+
+\buginvol D, in general (4/6/87)
+
+\tenpoint\noindent[The percent signs in all the comments (for example,
+on pages 7 and 42) are in the wrong font! Change `{\tt\%}' to `\%'.]
+
+\bugonpage Dvii, line 9 (9/25/86)
+
+{\tenpoint\noindent\hsize=29pc
+{\sl Discrete and Computational Geometry\/ \bf1} (1986), 123--140.
+\ \it Develops the theory\cutpar}
+
+\bugonpage D2, line 27 (6/17/86)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]METAFONT,\]Version\]1.3\char'23}\quad
+$\{\,$printed when \MF\ starts$\,\}$
+
+\bugonpage D18, line 30 (5/22/86)
+
+\ninepoint\noindent
+\\{str\_ptr}: \\{str\_number};\quad
+$\{\,$number of the current string being created$\,\}$
+
+\bugonpage D23, second line of mini-index, right column (6/14/87)
+
+\eightpoint
+\indent\\{pool\_name}\unhcopy\eqbox|"string"|, \S11.
+
+\bugonpage D30, lines 33--34 (6/14/87)
+
+\tenpoint\noindent
+to delete a token, and/or if some fatal error
+occurs while \MF\ is trying to fix a non-fatal one. But such recursion
+is never more than two levels deep.
+
+\bugonpage D63, lines 13--14 (5/5/87)
+
+\ninepoint\noindent
+[These two lines can be eliminated, since the variable \\{temp\_ptr}
+is no longer used! If you delete them, also remove \S158 from the
+list of sections where global variables are declared (pages D7 and D552),
+and remove \\{temp\_ptr} from the index on page D540.]
+
+\bugonpage D66, line 6 (5/22/86)
+
+\ninepoint\noindent
+{\bf function\/}\  $\\{get\_node}(s:\\{integer})$: \\{pointer};\quad
+$\{\,$variable-size node allocation$\,\}$
+
+\bugonpage D66, lines 31--32 (3/16/86)
+
+\tenpoint\noindent
+controlled
+growth helps to keep the \\{mem} usage consecutive when \MF\ is
+implemented on ``virtual memory'' systems.
+
+\bugonpage D67, lines 7--8 (4/21/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf if} $r=p$ {\bf then if} $\\{rlink}(p)\ne p$ {\bf then}
+  $\langle\,$Allocate entire node $p$ and {\bf goto} \\{found}%
+  {\sevenrm\kern.5em171}$\,\rangle$;
+
+\bugonpage D86, second line of section 198 (2/27/87)
+
+\noindent
+Individual class numbers have no semantic
+or syntactic significance, except in a few instances\cutpar
+
+\bugonpage D101, line 2 (3/16/86)
+
+\tenpoint\line{%
+like `{\tt x}', or they can
+combine the structural properties of arrays and records, like `{\tt x20a.b}'.
+A}
+
+\bugonpage D102, line 24 (3/16/86)
+
+\tenpoint\line{\kern10pt
+In other words, variables have a hierarchical structure that includes
+enough threads running}
+
+\bugonpage D127, line 10 (5/5/87)
+
+\ninepoint\noindent
+[Variable $r$ can be eliminated, since it is not
+used in this procedure! If you delete it, also remove $\underline{280}$
+from the corresponding index entry on page D536.]
+
+\bugonpage D129, line 15 (5/5/87)
+
+\ninepoint\noindent
+[This line can be eliminated, since \\{sine} and \\{cosine} are not
+used in this procedure! If you delete them, also remove $\underline{284}$
+from the corresponding index entries on pages D538 and D521.]
+
+\bugonpage D142, line 23 (4/24/87)
+
+\tenpoint\noindent
+$(7-\sqrt{28}\,)/12$; the worst case
+occurs for polynomials like $B(0,28-4\sqrt{28},14-5\sqrt{28},42;t)$.)
+
+\bugonpage D178, third-last line (7/30/86)
+
+\tenpoint\line{\quad
+The following code maintains the invariant relations
+$0\le \\{x0}<\max(\\{x1},\\{x1}+\\{x2})$, $\vert\\{x1}\vert<2^{30}$,}
+
+\bugonpage D228, line 13 (7/30/86)
+
+\ninepoint\noindent\kern10pt
+{\bf while} $\\{max\_coef}<\\{fraction\_half}$ {\bf do}
+
+\smallskip\eightpoint\noindent
+The mini-index at the bottom of the next page should also receive the following
+new entry:
+\smallskip\indent
+$\\{fraction\_half}={\rm macro}$, \S105.
+
+\bugonpage D228, 10th-last line (5/5/87)
+
+\ninepoint\noindent\hskip20pt
+{\bf begin} $\\{right\_type}(p)\gets k$;
+\smallskip
+\noindent[Also eliminate `$q,$' seven lines above this, and delete
+$\underline{497}$ from the index entry for \\{q} on page D536.]
+
+\bugonpage D248, lines 16--21 (11/27/86)
+
+\ninepoint\noindent\kern10pt
+$\\{alpha}\gets\\{abs}(u)$;\kern5pt
+ $\\{beta}\gets\\{abs}(v)$;\par\noindent\kern10pt
+{\bf if} $\\{alpha}<\\{beta}$ {\bf then}\par\noindent\kern20pt
+{\bf begin} $\\{alpha}\gets\\{abs}(v)$;\kern5pt
+ $\\{beta}\gets\\{abs}(u)$;\kern5pt
+{\bf end};\quad$\{\,$now $\alpha=\max(\vert u\vert,\vert v\vert)$,
+ $\beta=\min(\vert u\vert,\vert v\vert)\,\}$\par\noindent\kern10pt
+{\bf if} $\\{internal}[\\{fillin}]\ne0$ {\bf then}\par\noindent\kern20pt
+$d\gets d-\\{take\_fraction}(\\{internal}[\\{fillin}],
+ \\{make\_fraction}(\\{beta}+\\{beta},\\{delta}))$;\par\noindent\kern10pt
+$d\gets\\{take\_fraction}((d+4)\;{\bf div}\;8,\\{delta})$;\kern5pt
+$\\{alpha}\gets\\{alpha}\;{\bf div}\;\\{half\_unit}$;
+
+\bugonpage D263, line 20 (3/16/86)
+
+\tenpoint\noindent
+instead of \\{false}, the other routines will simply log the fact
+that they have been called; they won't\cutpar
+
+\bugonpage D268, line 2 (4/28/87)
+
+\tenpoint\noindent
+Given the number~$k$ of an open window, the pixels of positive
+weight in \\{cur\_edges} will be shown\cutpar
+
+\bugonpage D301, line 6 of section 652 (5/5/87)
+
+\ninepoint\noindent
+[This line can be eliminated, since variable $s$ is not
+used in this procedure! If you delete it, also remove $\underline{652}$
+from the corresponding index entry on page D537; remove 652 from
+the index entries for \\{param\_size} and \\{param\_start} on page D534;
+and remove \\{param\_size} from the mini-index on page D301.]
+
+\bugonpage D376, lines 17 and 18 (11/14/86)
+
+\tenpoint\noindent
+[these two mysterious lines should be deleted]
+
+\bugonpage D380, line 11 (5/5/87)
+
+\ninepoint\noindent
+[Variables $q$ and $r$ can be eliminated, since they are not
+used in this procedure! If you delete them, also remove $\underline{862}$
+from the corresponding index entries on page D536.]
+
+\bugonpage D429, line 14 (5/5/87)
+
+\ninepoint\noindent\hskip10pt
+{\bf begin} $p\gets\\{cur\_exp}$;
+\smallskip
+\noindent[Also eliminate line 12, and delete $\underline{985}$ from the
+index entry for \\{vv} on page D543.]
+
+\bugonpage D455, line 5 (5/5/87)
+
+\ninepoint\noindent
+[This line can be eliminated, since variable $t$ is not
+used in this procedure! If you delete it, also remove $\underline{1059}$
+from the corresponding index entry on page D540; remove 1059 from
+the index entries for \\{small\_number} and \\{with\_option} on pages D539
+and D544; and remove \\{with\_option} from the mini-index on page D455.]
+
+\bugonpage D463, line 10 (12/15/86)
+
+\ninepoint\noindent\hskip30pt
+({\tt"Pretend\]that\]you're\]Miss\]Marple:\]Examine\]all\]clues,"})
+
+\bugonpage D465, lines 17--18 (6/14/87)
+
+\tenpoint\noindent
+[Delete these two lines.]
+
+\bugonpage D474, 5th-last line (3/16/86)
+
+\tenpoint\noindent
+depths, or italic corrections) are sorted;
+then the list of sorted values is perturbed, if necessary.
+
+\bugonpage D481, line 12 (6/17/86)
+
+\ninepoint\noindent\hskip10pt
+\\{print\_nl}({\tt\char`\"Font\]metrics\]written\]on\]\char`\"});\kern5pt
+\\{print}(\\{metric\_file\_name});\kern5pt
+\\{print\_char}({\tt\char`\".\char`\"});
+
+\noindent\hskip10pt\\{b\_close}(\\{tfm\_file})
+
+\smallskip\eightpoint\noindent
+The mini-index at the bottom of this page should also receive the following
+new entry:
+\smallskip\indent
+\\{print\_char}: {\bf procedure}, \S58.
+
+\bugonpage D510, new line to follow line 5 (6/17/86)
+
+{\tenpoint\parindent=1em
+This program doesn't bother to close the input files that may still be open.
+\par}
+
+\bugonpage D510, just before the fifth-last line (8/5/86)
+
+\ninepoint\noindent\hskip30pt$\\{internal}[\\{fontmaking}]\gets0$;\quad
+$\{\,$avoid loop in case of fatal error$\,\}$
+
+\bugonpage D520, right column (6/14/87)
+
+\eightpoint
+\leftline{Chinese characters:\quad 1147.}
+
+\bugonpage D526, left column, lines 1--2 (7/30/86)
+
+\eightpoint
+\leftline{\indent\\{fraction\_half}:\quad
+ $\underline{105}$, 111, 152, 288, 408, 496, 543,}
+\leftline{\indent\qquad 1098, 1128, 1141.}
+
+\bugonpage D526, left column, lines 6--7 (7/30/86)
+
+\eightpoint
+\leftline{\indent\qquad 478, 497, 499, 503, 530, 540, 547, 549, 599, 603,}
+\leftline{\indent\qquad 612, 615, 815--816, 917, 1169--1170.}
+
+\bugonpage D528, right column (6/14/87)
+
+\eightpoint
+\leftline{Japanese characters:\quad 1147.}
+
+\bugonpage D530, right column, line 45 (7/30/86)
+
+\eightpoint
+\leftline{\indent\\{max}:\quad$\underline{539}$, 543.}
+
+\bugonpage D533, right column (6/14/87)
+
+\eightpoint
+\leftline{oriental characters:\quad 1147.}
+
+\bugonpage D535, right column, line 27 (6/17/86)
+
+\eightpoint
+\leftline{\indent\qquad 1134, 1163--1165, 1182, 1194, 1200, 1205, 1213.}
+
+\bugonpage D547, bottom two lines (11/27/86)
+
+\ninepoint\noindent
+[These lines, and the top two on the next page, should move down
+so that they appear in alphabetical order just before `Compute
+test coefficients'.]
+% volume E
+\hsize=29pc
+\def\dashto{\mathrel{\hbox{-\kern-.05em}\mkern3.9mu\hbox{-\kern-.05em}}}
+
+\bugonpage Exiii, lines 1--2 (7/28/86)
+
+\tenpoint\noindent
+February 11--13, 1984), 49.
+\ {\it An example meta-character of the Devanagari alphabet, worked out
+``online'' with the help of Matthew Carter.}
+
+\bugonpage Exiii, line 6 (7/28/86)
+
+\tenpoint\noindent
+{\it and western alphabets work also for Devanagari and Tamil.}
+
+\bugonpage E12, lines 15 and 19 (7/23/86)
+
+\tenpoint\noindent[change `17.32' to `17.28' in both places]
+
+\bugonpage E12, third-last line (12/18/86)
+
+\tenpoint\noindent[change `41' to `40']
+
+\bugonpage E13, lines 3, 4, and 20 (12/18/86)
+
+\tenpoint\noindent[change `40' to `41', `48' to `47', `17' to `7']
+
+\bugonpage E18, line 20 (7/23/86)
+
+\tenpoint\noindent[change `17.32' to `17.28']
+
+\bugonpage E18, line 29 (12/9/86)
+
+\tenpoint\noindent[change `236' to `212' in the {\tt cmss9} column]
+
+\bugonpage E170, top illustration (11/2/86)
+
+\tenpoint\noindent[There should be no ``dish'' or depression in the
+vicinity of point {\tt 3r}; the top edge of the character should be
+straight. This error appears also in the other uses of `\\{no\_dish\_serif}'
+throughout the book, since the illustrations were made before
+`\\{no\_dish\_serif}' was added to the program. See page
+E180~(twice at the top), E370~(twice), E374~(twice), E376~(twice), E378~(top),
+E390~(bottom), E398~(top), E402~(top), E406~(top), E453~(twice).]
+
+\bugonpage E179, new line to be inserted after line 6 (10/13/86)
+
+\ninepoint\noindent
+{\bf if}  $\\{shaved\_stem}<\\{crisp}.\\{breadth}$:
+  $\\{shaved\_stem}:=\\{crisp}.\\{breadth}$; {\bf fi}
+
+\bugonpage E219, line 29 (6/2/87)
+
+\ninepoint\line{\\{top} $y_1=h$; \ $x_1=x_2$; \
+ {\bf filldraw stroke} $z_{1e}\dashto z_{2'e}$;\hfil\% stem}
+
+\bugonpage E279, seventh line from the bottom (7/20/86)
+
+\rightline{\eightssi that delicious but restrained humor which
+ her readers found so irresistible.}
+
+\bugonpage E301, new line to be inserted after line 28 (5/15/87)
+
+\ninepoint\noindent
+\quad{\bf if} $\\{lower\_side}>1.2\\{upper\_side}$:
+  $\\{upper\_side}:=\\{lower\_side}$; {\bf fi}
+
+\bugonpage E554, bottom half of page (12/18/86)
+
+\ninepoint\noindent[The letters will change slightly because of the
+corrections to {\tt cmr17} noted on pages 12 and 13.]
+
+\bugonpage E561, line 3 (12/9/86)
+
+\ninepoint\noindent[The numerals should be `\thinspace
+{\niness 0123456789}\thinspace' (i.e., 2/3 point less tall)
+because of the correction made to page 18.]
+
+\bugonpage E562, line 9 (12/9/86)
+
+\ninepoint\noindent[The numerals should be `\thinspace
+{\ninessi 0123456789\/}\thinspace' (i.e., 2/3 point less tall)
+because of the correction made to page 18.]
+
+\bugonpage E572, entry for {\it breadth} (10/13/86)
+
+\eightpoint
+{\it breadth}, 59, 75, 79, 91, 93, 179, 225, 233,
+
+\bugonpage E573, entry for {\tt cmcsc10} (8/17/86)
+
+\eightpoint
+{\tt cmcsc10}, $\underline{30}$--$\underline{31}$, 567.
+
+\bugonpage E576, tenth-last line (5/15/87)
+
+\eightpoint
+{\bf lowres\kern.04em\vbox{\hrule width.3em height .6pt}\kern.08em
+ fix}, 550.
+\bye
+Now here are some that I will make soon!
+
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.twelve b/Master/texmf-dist/doc/generic/knuth-errata/errata.twelve
new file mode 100644
index 00000000000..8a7c291b490
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.twelve
@@ -0,0 +1,1709 @@
+% Bugs (sigh) in Computers \& Typesetting
+
+\input manmac
+\def\.#1{\hbox{\tt#1}}
+\font\sltt=cmsltt10
+\font\niness=cmss9
+\font\ninessi=cmssi9
+\proofmodefalse
+\raggedbottom
+\output{\hsize=29pc \onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\today{\number\day\
+  \ifcase\month\or
+  Jan\or Feb\or Mar\or Apr\or May\or Jun\or
+  Jul\or Aug\or Sep\or Oct\or Nov\or Dec\fi
+  \ \number\year}
+
+\def\cutpar{{\parfillskip=0pt\endgraf}}
+
+\def\rhead{Bugs in {\tensl Computers \& Typesetting as of \today}}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\buginvol#1(#2) \par{\bigbreak\penalty-1000\tenpoint
+  \hrule width\hsize
+  \line{\lower3.5pt\vbox to13pt{}Volume #1\hfil(#2)}\hrule width\hsize
+  \nobreak\medskip}
+\def\slMF{{\manual 89:;}\-{\manual <=>:}} % slant the logo
+\def\0{\raise.7ex\hbox{$\scriptstyle\#$}}
+\newcount\nn
+\newdimen\nsize \newdimen\msize \newdimen\ninept \ninept=9pt
+\newbox\eqbox \setbox\eqbox=\hbox{\kern2pt\eightrm=\kern2pt}
+
+\tenpoint
+\noindent This is a list of all substantial corrections made to {\sl Computers
+\& Typesetting\/} between the publication of the second ``Millennium Edition''
+at the close of the year 2001 and the beginning of the year 2014.
+(More precisely, it lists errors corrected
+in 16th to 19th printings of Volume~A, the 7th and 8th printings
+of Volume~B, the 6th and 7th printings of Volume~C, the 4th and 5th printings
+of Volume~D, and the 5th and 6th printings of Volume~E.)
+Corrections made to the softcover version of {\sl The \TeX book\/},
+beginning with its 32nd printing, are
+the same as corrections to Volume~A\null. Corrections to the softcover
+version of {\sl The \slMF\kern1ptbook}, beginning with its 11th printing,
+are the same as corrections to Volume~C\null. Changes to the mini-indexes
+and master indexes of Volumes B, D, and~E are not shown here unless they are
+not obviously derivable from what has been shown. All of these
+errors have supposedly been corrected in more recent printings, unless
+they were subsequently found to be wrong.
+\looseness=-1
+
+% volume A
+
+\bugonpage A7, line 4 from the bottom (01/15/04)
+
+\noindent
+since control sequences of the second kind always have exactly one
+symbol after\cutpar
+
+\bugonpage A123, line 7 from the bottom (02/27/08)
+
+\ninepoint\noindent
+that it won't make the natural height-plus-depth
+of\/ |\box|$\,n$ surpass |\dimen|$\,n$, when it~is\cutpar
+
+\bugonpage A124, lines 12 and 13 (02/27/08)
+
+\ninepoint\noindent
+means that \TeX\ has tried to split an |\insert254| to height $180.2\pt$;
+the natural height-plus-depth of the best such split is $175.3\pt$,
+and the penalty for breaking there is~100.)
+
+\bugonpage A153, line 7 (01/03/14)
+
+\ninepoint\noindent
+of three fonts: one for text size, one for
+script size, and one for scriptscript size. The\cutpar
+
+\bugonpage A206, lines 12--17 (05/21/07)
+
+\ninepoint\noindent
+or alignment template
+is also considered to be |\outer| in this sense; for example, a
+file shouldn't end in the middle of a definition. If you are designing a
+format for others to use, you can help them detect errors before too much
+harm is done, by using |\outer| with all control sequences that should
+appear only at ``quiet times'' within a document. For example, Appendix~B
+defines |\proclaim| to be |\outer|, since a user shouldn't be stating a
+theorem as part of a definition or argument or preamble.
+
+
+\bugonpage A216, line 3 from the bottom (12/20/07)
+
+\ninepoint\indent|\openin|\<number>|=|\<file name>
+
+\bugonpage A290, lines 25--26 (02/24/08)
+
+\ninepoint\textindent{$\bull$}
+\<leaders>\<box or rule>\<horizontal skip>.\enskip
+Here \<horizontal skip> refers to one of the first five glue-appending
+commands just mentioned; the formal syntax for \<leaders>\cutpar
+
+\bugonpage A292, line 15 (12/02/02)
+
+\ninepoint\noindent
+are defined as in the
+second alternative of a \<math field>, are
+recorded in a ``choice\cutpar
+
+\bugonpage A308, lines 25 and 26 (06/17/02)
+
+\ninepoint
+\begintt
+\def\appendroman#1#2#3{\expandafter\def\expandafter#1\expandafter
+  {\csname\expandafter\gobble\string#2\romannumeral#3\endcsname}}
+\endtt
+
+\bugonpage A311, line 14 (12/02/02)
+
+\ninepoint\indent
+|\def\\{\if\space\next\ % assume that \next is unexpandable|
+
+\bugonpage A311, line 17 (12/29/07)
+
+\ninepoint\indent
+|  \leavevmode\copy0\kern-\wd0\makelightbox}|
+
+\bugonpage A318, lines 24 and 25 (10/01/03)
+
+\ninepoint\noindent
+\hbox to\parindent{\bf\hss15.13.\enspace}%
+Yes, in severe circumstances.  (1)~Previous footnotes might
+ have left no room for any more footnotes on the page.
+(2)~If |\vadjust{\eject}| occurs on the same line\cutpar
+
+\bugonpage A364, lines 12--15 from the bottom (02/29/08)
+
+\ninepoint\noindent
+|\def\loggingall{\tracingcommands=2 \tracingstats=2|\par\noindent
+|  \tracingpages=1 \tracingoutput=1 \tracinglostchars=1 |\par\noindent
+|  \tracingmacros=2 \tracingparagraphs=1 \tracingrestores=1 |\par\noindent
+|  \showboxbreadth=\maxdimen \showboxdepth=\maxdimen}|\par
+\noindent
+|\def\tracingall{\tracingonline=1 \loggingall}|
+
+\bugonpage A364, line 5 from the bottom (02/29/08)
+
+\ninepoint\noindent
+|\def\fmtversion{3.141592653} % identifies the current format|
+
+\bugonpage A373, lines 4 and 5 from the bottom (01/02/14)
+
+\ninepoint\noindent
+And here's another solution (which may be faster, because
+token list registers can be expanded more quickly than macros
+on some implementations, using |\the|):
+
+\bugonpage A373, line 2 from the bottom (01/02/14)
+
+\ninepoint\indent
+|\loop \ifnum\m>0 \t=\expandafter{\the\t*}\advance\m-1 \repeat|
+
+\bugonpage A399, line 18, through what used to be page A400, line 14 (02/26/08)
+
+\ninepoint
+Finally, the reformatting of\/ |\box\footins| can be achieved easily with
+an elegant technique suggested by David Kastrup, using the following
+\TeX\ code within the |\output| routine:
+\begindisplay
+|\def\makefootnoteparagraph{\unvbox\footins|\cr
+|  \baselineskip=\footnotebaselineskip \removehboxes}|\cr
+|\def\removehboxes{\unskip\setbox0=\lastbox|\cr
+|  \ifhbox0{\removehboxes}\unhbox0 \else\noindent \fi}|\cr
+\enddisplay
+The key idea here is |\removehboxes|, a macro that has the magical ability to
+take a vertical box such as `|\vbox{\box1\box2\box3\removehboxes}|' and
+transform it into
+`|\vbox{\noindent\unhbox1\unhbox2\unhbox3}|'\kern-1pt,
+if\/ |\box1|, \kern-2pt|\box2|, and
+|\box3| are hboxes. Notice how |\removehboxes| introduces braces so that
+\TeX's {save stack} will hold all of the hboxes before they are unboxed. Each
+level of recursion in this routine uses one cell of input stack space and
+three cells of save stack space; thus, it is generally safe to do more than
+100 footnotes without exceeding \TeX's capacity.
+
+In our application there is no interline glue within |\box\footins|,
+so the |\unskip| command could be deleted from |\removehboxes|.
+
+Incidentally, the |\unskip| and |\lastbox| operations have running
+times of the approximate form
+$a+mb$, where $m$~is the number of items on the
+list preceding the glue or box that is removed. Hence |\removehboxes| has a
+running time of order $n^2$ when it removes $n$~boxes.
+But the constant~$b$ is so small that
+for practical purposes it's possible to think of\/ |\unskip| and
+|\lastbox| as almost instantaneous.
+
+\bugonpage A416, lines 18--22 (06/08/07)
+
+\ninepoint\noindent\beginlines
+|\def\leftheadline{\hbox to \pagewidth{\spaceskip=0pt|
+|    \vbox to 10pt{}% strut to position the baseline|
+|    \llap{\tenbf\folio\kern1pc}% folio to left of text|
+|    \tenit\rhead\hfil}} % running head flush left|
+|\def\rightheadline{\hbox to \pagewidth{\spaceskip=0pt\vbox to 10pt{}%|
+\endlines
+
+\bugonpage A418, line 8 from the bottom (12/13/11)
+
+\ninepoint\noindent\beginlines
+|    \def\\{#3} \advance\hsize by -18mm|
+\endlines
+
+\bugonpage A418, line 3 from the bottom (12/13/11)
+
+\ninepoint\noindent\beginlines
+|    \halign{\line{\titlefont\hss##}\\#4\unskip\\}|
+\endlines
+
+\bugonpage A442, lines 7 and 8 from the bottom (01/03/14)
+
+\def\rule#1.{\smallskip\textindent{\bf#1.}\ignorespaces}
+\ninepoint\textindent{\bf 3.}%
+If the current item is a style change, set $C$ to the specified
+style and move on to the next item.
+
+\bugonpage A450, lines 14--16 from the bottom (12/19/02)
+
+\begingroup\def\\#1{$_{\kern\scriptspace#1}$}
+\indent\qquad{\tt s\\1tic
+  \\1exp x\\3p pi\\3a \\2i\\1a i\\2al \\2id \\1do \\1ci \\2io ou\\2 \\2us}
+\medskip\noindent
+(where subscripts that aren't shown are zero), and this yields
+$$\centerline{%
+\tt.\\0s\\0u\\1p\\0e\\0r\\1c\\0a\\0l\\1i\\0f\\0r\\0a\\0g\\1i\\0l\\4i%
+\\0s\\1t\\2i\\0c\\1e\\0x\\3p\\2i\\3a\\0l\\2i\\1d\\0o\\1c\\2i\\0o\\2u\\2s\\0.}$$
+\endgroup
+
+\bugonpage A458, left column (01/11/07)
+
+\eightpoint\noindent
+|\\|, 38, {\it356}, {\it378}, {\it418}.
+
+\bugonpage A459, left column (03/17/06)
+
+\eightpoint\noindent
+angle brackets ( $\langle\,\rangle$ ), 59, {\it146--147}, 150,~156,\par
+\noindent\qquad $\underline{268}$, 420, 437;
+ {\sl see also\/} |\langle|, |\rangle|.
+
+\bugonpage A461, left column (02/24/08)
+
+\eightpoint\noindent
+|\boxit|, 223, 331.
+
+\bugonpage A468, right column (02/26/08)
+
+\eightpoint\noindent
+interline glue, 78--79, $\underline{80}$, 104, 105, 125, 221,\par
+\noindent\qquad 245, 263, 281--282, 335, 352, 399, 409.
+
+\bugonpage A469, left column (02/26/08)
+
+\eightpoint\noindent
+Kastrup, David Friedrich, 399.
+
+\bugonpage A470, left column (01/21/03)
+
+\eightpoint\noindent
+|\loggingall|, $\underline{364}$.
+
+\bugonpage A477, right column (06/08/07)
+
+\eightpoint\noindent
+\llap{*}|\spaceskip|, 76, 274, {\it317}, {\it356}, {\it416}, 429.
+
+\bugonpage A479, right column (09/11/07)
+
+\eightpoint\noindent
+|\undefined|, 350, 384.
+
+\bugonpage A483, line 5 from the bottom (11/18/03)
+
+\eightpoint
+\rightline{\eightss--- HIERONYMUS HORNSCHUCH, %
+  {\eightrm'}$O\mkern-1mu\rho\mkern1mu\vartheta o\mkern1mu %
+  \tau\upsilon\pi o\gamma\mkern-1mu %
+  \rho\alpha\phi\acute\iota\alpha\varsigma$\enspace(1608)}
+
+% volume B
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Bv, page number change (12/27/11)
+
+\eightpoint\noindent[For consistency with Volumes A, C, and E, the
+preface now begins on page v instead of page~vii. This change was first
+made in the ninth printing.]
+
+\bugonpage Bv {(formerly Bvii)}, bottom two lines (01/06/14)
+
+\eightpoint\noindent
+all of those changes.
+I~now believe that the final bug was discovered on 14 September 2008
+and removed in version 3.14159265.
+The finder's fee has converged to \$327.68.
+
+\bugonpage Bxiii {(formerly Bxv)}, line $-7$ (12/27/11)
+
+\ninepoint\noindent
+Format specs have no effect on the corresponding Pascal program, but they
+do influence\cutpar
+
+\hsize=35pc
+
+\bugonpage B2, line 10 from the bottom (01/02/14)
+
+\ninepoint\noindent\hskip10pt
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]TeX,\]Version\]3.14159265\char'23}\quad
+$\{\,$printed when \TeX\ starts$\,\}$
+
+\bugonpage B3, new paragraph to follow line 9 (12/20/02)
+
+\tenpoint\noindent\quad
+Incidentally, Pascal's standard \\{round} function can be problematical,
+because it disagrees with the IEEE floating-point standard.
+Many implementors have
+therefore chosen to substitute their own home-grown rounding procedure.
+
+\bugonpage B21, lines 33 and 34 (09/11/07)
+
+\def\Oct#1{\hbox{\rm\char'23\kern-.2em\it#1\/\kern.05em}} % octal constant
+\tenpoint\noindent
+$[\Oct{41}\to\Oct{46},\Oct{60}%
+\to\Oct{71},\Oct{136},\Oct{141}\to\Oct{146},\Oct{160}\to\Oct{171}]$ must be printable.
+Thus, at least 81 printable characters are needed.
+
+\bugonpage B109, line 16 (01/06/14)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{print\_esc}(\.{"csname"})$;
+$\\{print\_esc}(\.{"endcsname"})$;
+$\\{print\_char}(\.{"\ "})$;
+{\bf end}
+
+\bugonpage B114, line 25 (09/11/07)
+
+\def\#{\hbox{\tt\char`\#}} % parameter sign
+\ninepoint\noindent
+{\bf define} $\\{save\_index}(\#)\equiv\\{save\_stack}[\#].\\{hh}.\\{rh}$\quad
+ $\{\,$\\{eqtb} location or token or \\{save\_stack} location$\,\}$
+
+\bugonpage B139, line 20 (12/19/02)
+
+\ninepoint\noindent
+\quad{\bf begin while} $(\\{state}=\\{token\_list}) \land
+ (\\{loc}=\\{null}) \land (\\{token\_type}\ne\\{v\_template})$ {\bf do}\par
+\noindent\qquad\\{end\_token\_list};\quad$\{\,$conserve stack space$\,\}$
+
+\bugonpage B144, line 14 (09/11/07)
+
+\ninepoint\noindent
+\quad\\{cat}: $0\to\\{max\_char\_code}$;\quad$\{\,$\\{cat\_code}(\\{cur\_char}), usually$\,\}$
+
+\bugonpage B153, lines 2 and 3 (09/11/07)
+
+\tenpoint\noindent
+In fact, these three procedures account for almost every use of \\{get\_next}.
+
+\bugonpage B161, line 19 (12/19/02)
+
+\ninepoint\noindent
+\quad{\bf while} $(\\{state}=\\{token\_list}) \land
+ (\\{loc}=\\{null}) \land (\\{token\_type}\ne\\{v\_template})$ {\bf do}\par
+\noindent\qquad\\{end\_token\_list};\quad$\{\,$conserve stack space$\,\}$
+
+\bugonpage B163, line 29 (12/19/02)
+
+\ninepoint\noindent
+\quad$\\{long\_state}\gets\\{call}$;
+$\\{cur\_tok}\gets\\{par\_token}$;
+$\\{ins\_error}$;
+{\bf goto} \\{continue};
+
+\bugonpage B172, lines 2--6 from the bottom (09/11/07)
+
+\ninepoint\noindent
+{\bf else if\/} $m=\\{vmode}$ {\bf then} \\{scanned\_result}(\\{prev\_depth})(\\{dimen\_val})\par\noindent
+\quad{\bf else} \\{scanned\_result}(\\{space\_factor})(\\{int\_val})
+
+\bugonpage B178, line 4 (09/11/07)
+
+\ninepoint\noindent
+\quad$\\{cur\_val}\gets0$;
+$\\{cur\_val\_level}\gets\\{int\_val}$;
+$\\{radix}\gets0$;
+$\\{cur\_order}\gets\\{normal}$;
+
+\bugonpage B184, line 9 from the bottom (04/18/07)
+
+\tenpoint\noindent
+and denominator sum to 32768 or less.
+According to the definitions here, $\rm2660\,dd\approx1000.33297\,mm$;\kern-6.6pt\cutpar
+
+\bugonpage B206, line 14 (10/30/02)
+
+\tenpoint\noindent
+used input files like \.{webmac.tex}.
+
+\bugonpage B206, new paragraph to follow line 22 (12/20/02)
+
+\tenpoint\noindent\quad
+The following procedures don't allow spaces to be part of
+file names; but some users seem to like names that are spaced-out.
+System-dependent changes to allow such things should probably
+be made with reluctance, and only when an entire file name that
+includes spaces is ``quoted'' somehow.
+
+\bugonpage B227, new line to precede line 23 (09/11/07)
+
+\ninepoint\noindent
+{\bf if} $(\\{nw}=0)\lor(\\{nh}=0)\lor(\\{nd}=0)\lor(\\{ni}=0)$
+ {\bf then} \\{abort};
+
+\bugonpage B256, line 25 (12/20/02)
+
+\ninepoint\noindent
+\qquad\\{cur\_glue}: \\{real};\quad$\{\,$glue seen so far$\,\}$\par\noindent
+\qquad\\{cur\_g}: \\{scaled};\quad$\{\,$rounded
+  equivalent of \\{cur\_glue} times the glue ratio$\,\}$\par\noindent
+\quad{\bf begin} $\\{cur\_g}\gets0$;
+  $\\{cur\_glue}\gets\\{float\_constant}(0)$;\par\noindent
+\quad$\\{this\_box}\gets\\{temp\_ptr}$;
+ $\\{g\_order}\gets\\{glue\_order}(\\{this\_box})$;
+ $\\{g\_sign}\gets\\{glue\_sign}(\\{this\_box})$;
+
+\bugonpage B258, line 5 from the bottom (12/20/02)
+
+\ninepoint\noindent
+\quad{\bf begin} $g\gets\\{glue\_ptr}(p)$;
+  $\\{rule\_wd}\gets\\{width}(g)-\\{cur\_g}$;
+
+\bugonpage B258, bottom line (12/20/02)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{cur\_glue}\gets\\{cur\_glue}+\\{stretch}(g)$;
+ $\\{vet\_glue}(\\{float}(\\{glue\_set}(\\{this\_box}))*\\{cur\_glue})$;\par
+\noindent\qquad\qquad$\\{cur\_g}\gets\\{round}(\\{glue\_temp})$;
+
+\bugonpage B259, line 4 (12/20/02)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{cur\_glue}\gets\\{cur\_glue}-\\{shrink}(g)$;
+ $\\{vet\_glue}(\\{float}(\\{glue\_set}(\\{this\_box}))*\\{cur\_glue})$;\par
+\noindent\qquad\qquad$\\{cur\_g}\gets\\{round}(\\{glue\_temp})$;
+
+\bugonpage B259, new line to precede old line 7 (12/20/02)
+
+\ninepoint\noindent
+\quad$\\{rule\_wd}\gets\\{rule\_wd}+\\{cur\_g}$;
+
+\bugonpage B260, line 21 (12/19/02)
+
+\ninepoint\noindent
+\qquad{\bf else begin} $\\{lx}\gets\\{lr}$ {\bf div} $(\\{lq}+1)$;
+
+\bugonpage B261, line 9 (12/20/02)
+
+\ninepoint\noindent
+\qquad\\{cur\_glue}: \\{real};\quad$\{\,$glue seen so far$\,\}$\par\noindent
+\qquad\\{cur\_g}: \\{scaled};\quad$\{\,$rounded
+  equivalent of \\{cur\_glue} times the glue ratio$\,\}$\par\noindent
+\quad{\bf begin} $\\{cur\_g}\gets0$;
+  $\\{cur\_glue}\gets\\{float\_constant}(0)$;\par\noindent
+\quad$\\{this\_box}\gets\\{temp\_ptr}$;
+ $\\{g\_order}\gets\\{glue\_order}(\\{this\_box})$;
+ $\\{g\_sign}\gets\\{glue\_sign}(\\{this\_box})$;
+
+\bugonpage B262, line 10 from the bottom (12/20/02)
+
+\ninepoint\noindent
+\quad{\bf begin} $g\gets\\{glue\_ptr}(p)$;
+  $\\{rule\_ht}\gets\\{width}(g)-\\{cur\_g}$;
+
+\bugonpage B262, line 6 from the bottom (12/20/02)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{cur\_glue}\gets\\{cur\_glue}+\\{stretch}(g)$;
+ $\\{vet\_glue}(\\{float}(\\{glue\_set}(\\{this\_box}))*\\{cur\_glue})$;\par
+\noindent\qquad\qquad$\\{cur\_g}\gets\\{round}(\\{glue\_temp})$;
+
+\bugonpage B262, line 2 from the bottom (12/20/02)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{cur\_glue}\gets\\{cur\_glue}-\\{shrink}(g)$;
+ $\\{vet\_glue}(\\{float}(\\{glue\_set}(\\{this\_box}))*\\{cur\_glue})$;\par
+\noindent\qquad\qquad$\\{cur\_g}\gets\\{round}(\\{glue\_temp})$;
+
+\bugonpage B263, new line to precede old line 2 (12/20/02)
+
+\ninepoint\noindent
+\quad$\\{rule\_ht}\gets\\{rule\_ht}+\\{cur\_g}$;
+
+\bugonpage B264, line 10 (12/19/02)
+
+\ninepoint\noindent
+\qquad{\bf else begin} $\\{lx}\gets\\{lr}$ {\bf div} $(\\{lq}+1)$;
+
+\bugonpage B266, line 29 (09/11/07)
+
+\tenpoint\noindent
+$\\{total\_pages}\ge65536$, the \.{DVI} file will lie. And if
+$\\{max\_push}\ge65536$, the user deserves whatever chaos might ensue.
+
+\bugonpage B279, line 19 (09/11/07)
+
+\ninepoint\noindent
+\qquad\\{p}: \\{pointer};\quad$\{\,$a new glue node$\,\}$
+
+\bugonpage B288, lines 18--20 (09/11/07)
+
+\ninepoint\noindent
+\\{left\_noad}: {\bf begin} \\{print\_esc}(\.{"left"});
+  \\{print\_delimiter}(\\{delimiter}($p$));\par\noindent
+\quad{\bf end};\par\noindent
+\\{right\_noad}: {\bf begin} \\{print\_esc}(\.{"right"});
+  \\{print\_delimiter}(\\{delimiter}($p$));
+
+\bugonpage B290, line 12 (09/11/07)
+
+\ninepoint\noindent
+\quad{\bf begin if\/} $s=\\{text\_size}$ {\bf then}
+ \\{print\_esc}(\.{"textfont"});
+
+\bugonpage B299, line 9 (12/20/02)
+
+\ninepoint\noindent
+\qquad\qquad\quad{\bf if\/} $\\{type}(r)=\\{kern\_node}$ {\bf then}
+ \quad$\{\,$unneeded italic correction$\,\}$
+
+\bugonpage B332, line 6 (12/19/02)
+
+\tenpoint\noindent
+is being scanned, or when no alignment preamble is active.
+
+\bugonpage B332, line 8 (12/19/02)
+
+\ninepoint\noindent
+\quad{\bf begin if\/} $(\\{scanner\_status}=\\{aligning}) \lor
+ (\\{cur\_align}=\\{null})$ {\bf then}
+
+\bugonpage B336, line 11 from the bottom (10/13/03)
+
+\tenpoint\noindent
+$j-i+\\{min\_quarterword}$ in their
+\\{link} fields. The values of $w_{ii}$ were initialized to
+\\{null\_flag},\cutpar
+
+\bugonpage B342, lines 5 and 6 (09/11/07)
+
+\tenpoint
+In restricted horizontal mode, the \\{clang} part of \\{aux} is undefined;
+an over-cautious Pascal runtime system may complain about this.
+
+\bugonpage B343, line 25 (01/02/13)
+
+\noindent
+should begin in the
+sequence of line numbers, in case hanging indentation or \.{\char`\\parshape}
+is in\cutpar
+
+\bugonpage B416, line 22 (02/29/08)
+
+\ninepoint\noindent
+\qquad\qquad{\bf if\/} $\\{count}(t)=1000$ {\bf then} $t\gets\\{height}(r)$
+\par\noindent
+\qquad\qquad{\bf else} $t\gets\\{x\_over\_n}(\\{height}(r),1000)*\\{count}(t)$;
+\par\noindent
+\qquad\qquad\\{print\_scaled}$(t)$
+
+\bugonpage B438, lines 1--3 (09/11/07)
+
+\tenpoint\noindent
+{\bf1035.\quad}If \\{link}(\\{cur\_q}) is nonnull when \\{wrapup} is invoked,
+\\{cur\_q} points to
+the list of characters that were consumed while building the ligature
+character~\\{cur\_l}.
+
+\bugonpage B438, lines 19 and 20 (09/11/07)
+
+\ninepoint\noindent
+\qquad\qquad\qquad{\bf begin if\/} $\\{link}(\\{cur\_q})>\\{null}$ {\bf then}
+\par\noindent
+\qquad\qquad\qquad\quad{\bf if\/} $\\{character}(\\{tail})=\\{qi}(
+  \\{hyphen\_char}[\\{main\_f}])$ {\bf then} $\\{ins\_disc}\gets\\{true}$;
+
+\bugonpage B438, line 4 from the bottom (09/11/07)
+
+\ninepoint\noindent
+\quad$\\{link}(\\{tail})\gets\\{lig\_stack}$;
+$\\{tail}\gets\\{lig\_stack}$\quad$\{\,$\\{main\_loop\_lookahead} is next$\,\}$
+
+\bugonpage B439, line 3 (09/11/07)
+
+\ninepoint\noindent
+\quad{\bf if\/} $\\{main\_p}>\\{null}$ {\bf then}
+ \\{tail\_append}(\\{main\_p});\quad$\{\,$append a single character$\,\}$
+
+\bugonpage B440, new line to follow line 9 (09/11/07)
+
+\ninepoint\noindent
+\quad{\bf if\/} $\\{cur\_r}=\\{non\_char}$ {\bf then goto}
+ \\{main\_loop\_wrapup};
+
+\bugonpage B452, line 18 (28/03/11)
+
+\noindent\\{hmode}, where the latter two are used to denote
+ \.{\char`\\vbox} and \.{\char`\\hbox}, respectively.
+
+\bugonpage B455, lines 3 and 4 (09/11/07)
+
+\ninepoint\noindent
+\quad{\bf if\/} $((\\{cur\_cmd}=\\{hskip})\land(\\{abs}(\\{mode})\ne\\{vmode}))
+ \lor  ((\\{cur\_cmd}=\\{vskip})\land(\\{abs}(\\{mode})=\\{vmode}))$ {\bf then}
+
+\bugonpage B472, new paragraph to follow line 10 (12/20/02)
+
+\tenpoint\noindent\quad
+A devious user might force an \\{endv} command to occur just about anywhere;
+we must defeat such hacks.
+
+\bugonpage B472, replacement for what used to be line 13 (12/20/02)
+
+\ninepoint\noindent
+\quad{\bf begin} $\\{base\_ptr}\gets\\{input\_ptr}$;
+ $\\{input\_stack}[\\{base\_ptr}]\gets\\{cur\_input}$;\par\noindent
+\quad{\bf while} $(\\{input\_stack}[\\{base\_ptr}].\\{index\_field}\ne
+  \\{v\_template}) \land{}$\par\noindent
+\quad\qquad $(\\{input\_stack}[\\{base\_ptr}].\\{loc\_field}=
+  \\{null}) \land {}$\par\noindent
+\quad\qquad $(\\{input\_stack}[\\{base\_ptr}].\\{state\_field}=
+  \\{token\_list})$ {\bf do} \\{decr}(\\{base\_ptr});\par\noindent
+\quad{\bf if\/} $(\\{input\_stack}[\\{base\_ptr}].\\{index\_field}\ne
+  \\{v\_template}) \lor {}$\par\noindent
+\quad\qquad $(\\{input\_stack}[\\{base\_ptr}].\\{loc\_field}\ne
+  \\{null}) \lor {}$\par\noindent
+\quad\qquad $(\\{input\_stack}[\\{base\_ptr}].\\{state\_field}\ne
+  \\{token\_list})$ {\bf then}\par\noindent
+\qquad\\{fatal\_error}(\hbox{\tt\char'23(interwoven\]alignment\]preambles\]%
+    are\]not\]allowed)\char'23});\par\noindent
+\quad{\bf if\/} $\\{cur\_group}=\\{align\_group}$ {\bf then}
+
+\bugonpage B505, line 19 (09/11/07)
+
+\ninepoint\noindent
+\qquad(\.{"since\]the\]result\]is\]out\]of\]range."});\par\noindent
+\qquad{\bf if\/} $p\ge\\{glue\_val}$ {\bf then}
+   \\{delete\_glue\_ref}(\\{cur\_val});\par\noindent
+\qquad\\{error}; {\bf return};
+
+\bugonpage B506, line 1 (10/13/03)
+
+\tenpoint\noindent
+{\bf 1237.\quad}Here we use the fact that the consecutive codes
+$\\{int\_val}\to\\{mu\_val}$ and
+$\\{assign\_int}\to$\cutpar
+
+\bugonpage B520, line 8 (06/25/04)
+
+\tenpoint\noindent
+says,
+for example, `\.{(preloaded format=plain 1982.11.19)}', showing the year,
+month, and day\cutpar
+
+\bugonpage B535, new line to follow line 11 (09/11/07)
+
+\ninepoint\noindent
+\qquad{\bf if\/} $\\{last\_glue}\ne\\{max\_halfword}$ {\bf then}
+ \\{delete\_glue\_ref}(\\{last\_glue});
+
+\bugonpage B578, new entry (06/04/06)
+
+\eightpoint\noindent
+Trabb Pardo, Luis Isidoro, 2.
+
+% volume C
+\hsize=29pc
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\ddashto{\mathrel{\hbox{-\thinspace-\thinspace-\kern-.05em}}}
+\def\tension{\mathop{\rm tension}}
+\def\controls{\mathop{\rm controls}}
+\def\and{\,{\rm and}\,}
+
+\bugonpage Cxi, line 4 (05/20/07)
+
+\line{\hbox to\parindent{\bf\hbox to 1em{\hss27}\hss}%
+  \rm Recovery from Errors\leaders\hbox to 20pt{\kern13pt.\hss}\hfil
+  \hbox to 2em{\hss223}}
+
+\bugonpage C11, line 11 (10/11/01)
+
+\noindent
+the area below the bar to the area above it equal to
+$(\sqrt5+1)/2\approx1.61803$, the\cutpar
+
+\bugonpage C29, illustration for exercise 4.11 (09/09/01)
+
+\noindent
+[points 2 and 5 should not be labeled twice]
+
+\bugonpage C32, line 5 from the bottom (01/04/14)
+
+\noindent
+\hbox to\parindent{\hfil\sevenrm20\ \ }%
+|  penpos1(stem,15); penpos2(.9stem,12); penpos3(stem,10);|
+
+\bugonpage C36, line 5 from the bottom (01/05/14)
+
+\noindent
+line~12, where it
+says `|x1l|', not `|x11|' or~`|xll|'); be sure to distinguish between\cutpar
+
+\bugonpage C55, lines 5 and 6 (01/05/14)
+
+\ninepoint\noindent
+suffixed or subscripted.
+Thus, the syntax rule for \<variable>
+should actually be replaced by a slightly more complicated pair of rules:
+
+
+\bugonpage C129, line 16 (02/21/08)
+
+\ninepoint\beginsyntax
+<path subexpression>\is<path expression not ending with direction specifier>\kern-5pt\null
+\endsyntax
+
+\bugonpage C130, lines 13--15 from the bottom (09/13/03)
+
+\ninepoint\noindent
+point but not after it, the
+nonempty one is duplicated in a similar way. A~basic path join
+`$\to\controls u\and v\to$' specifies explicit control points that
+override any direction specifiers that may immediately surround it.
+
+\bugonpage C137, lines 5--7 from the bottom (02/21/08)
+
+\danger Let's conclude this chapter by applying what we've learned about
+paths to a real-life example. The {\sl Journal of Algorithms\/} was
+published for many years by Academic Press, and its cover page carried the
+following logo, which was designed\cutpar
+\enddanger
+
+\bugonpage C137, bottom two lines (02/21/08)
+
+\ninepoint\noindent
+A \MF\ program to produce this logo made it possible for the editors
+of the journal to use it on letterheads in their correspondence.
+Here is one way to do that job,\cutpar
+% actually the MS now says "to write that program," and the
+% correction therefore extends to page C138
+
+\bugonpage C156, line 15 from the bottom (09/09/01)
+
+\ninepoint\noindent
+be the values they had upon entry to the group.)
+
+\bugonpage C159, lines 12--15 (12/01/06)
+
+\begintt
+def --- = ..tension infinity.. enddef;
+\endtt
+it makes `$z_1\ddashto z_2$' become
+`$z_1\to\tension\\{infinity}\to z_2$'.
+The {replacement text} can be any sequence of tokens not including
+`{\bf enddef}\kern1pt'; or it can include entire subdefinitions like
+`{\bf def}~$\ldots$~{\bf enddef}\kern1pt', according to certain rules
+that we shall explain later.
+
+\bugonpage C171, line 16 from the bottom (06/18/02)
+
+\tenpoint
+\<loop>\is\<loop header>|:|\<loop text> {\tt endfor}
+
+\bugonpage C179, line 7 from the bottom (09/09/01)
+
+\ninepoint\noindent
+next time \MF\ gets to the end of an input line, it will stop reading
+from the\cutpar
+
+\bugonpage C180, lines 14--16 (04/25/03)
+
+\ninepoint\noindent
+digits should be a
+file name that works in essentially the same way on all installations of
+\MF\kern-.03em\null. Uppercase letters are considered to be distinct from their
+lowercase counterparts, on many systems.
+
+\bugonpage C180, new line to be inserted 4 from the bottom (06/25/04)
+
+\ninepoint\item\bull
+When \MF\ is reading the symbolic tokens to be saved by {\bf save}.
+
+\bugonpage C203, line 12 from the bottom (04/25/03)
+
+\ninepoint\hbox to 237pt{point~3 at the right of the triangle
+might digitize into a}
+
+\bugonpage C213, line 26 (02/21/08)
+
+\ninepoint\beginsyntax
+<path subexpression>\is<path expression not ending with direction specifier>\kern-5pt\null
+\endsyntax
+
+\bugonpage C226, line 23 (02/21/08)
+
+\ninepoint\noindent following nineteen things will be mentioned:
+
+\bugonpage C226, new line to be second from the bottom (02/21/08)
+
+\ninepoint\indent|independent variables|\qquad(distinct numeric variables)
+
+\bugonpage C236, line 7 from the bottom (01/05/14)
+
+\ninepoint\noindent
+\hbox to\parindent{\hss\bf 7.4.\enspace}False.
+After `|newinternal x;|' you can't say `|x|\<tag>' in a \<suffix list>.
+
+\bugonpage C246, line 12 (02/21/08)
+
+\ninepoint\noindent
+is performed whenever \MF\ uses the last two alternatives
+in the definition\cutpar
+
+\bugonpage C250, lines 13 and 14 (02/19/08)
+
+\ninepoint\noindent\hbox to\parindent{\bf\hss19.3.\enspace}%
+Yes, if and only if $n-{1\over2}$ is a nonnegative even integer.
+\ (Because ambiguous values are rounded upwards.)
+
+\bugonpage C250, line 12 from the bottom (04/25/03)
+
+\ninepoint\noindent
+following \<boolean primary>.)
+
+\bugonpage C286, line 25 (09/09/01)
+
+\ninepoint\noindent
+problem; it would simply have put |ENDFOR| into the
+replacement text of |asts|, because\cutpar
+
+\bugonpage C289, line 7 (09/09/01)
+
+\vskip-6pt\ninepoint\begintt
+if if pair x: x>(0,0) else: false fi: A else: B fi.
+\endtt
+
+\bugonpage C292, line 10 from the bottom (09/09/01)
+
+\ninepoint\noindent
+be known by saying `{\bf if\/} known $p-q$: $p=q$ {\bf else}:~{\bf false}
+{\bf fi}'; transforms could be handled\cutpar
+
+\bugonpage C293, line 5 from the bottom (04/25/03)
+
+\ninepoint\noindent
+given angle~$\phi$. We can consider
+the common angle~$\theta$ of $z_{1r}-z_{1l}$ and $z_{0r}-z_{0l}$ to be\cutpar
+
+\bugonpage C315, line 15 from the bottom (04/25/03)
+
+\ninepoint\noindent
+`b' was shipped out.) \ The second letter,~`o', is placed
+in a second little box adjacent\cutpar
+
+\bugonpage C325, bottom line (02/29/08)
+
+\rightline{\eightss--- CAROLUS LINN\AE US, 
+ {\eightssi Philosophia Botanica\/}\enspace(1751)}
+
+\bugonpage C332, line 4 from the bottom (04/25/03)
+
+\ninepoint\noindent
+(The proofsheet resolution will be 50 pixels per inch, because {\it cheapo\/}
+has 200 pixels per\cutpar
+
+\bugonpage C346, left column (06/18/02)
+
+\eightpoint\noindent
+\llap{*}|:|, 169, 171, 317--319.
+
+\bugonpage C346, right column (07/09/01)
+
+\eightpoint\noindent
+\llap{*}|angle|, {\it29}, {\it67}, $\underline{72}$, {\it107},
+{\it135}, 211, {\it238}.
+
+\bugonpage C346, right column (10/04/04)
+
+\eightpoint\noindent
+arccosine, arcsine, arctangent, {\sl see\/} |angle|.
+
+\bugonpage C351, right column (02/21/08)
+
+\eightpoint\noindent
+independent variables, $\underline{81}$--$\underline{83}$, 88, 224, 226.
+
+\bugonpage C352, right column (02/29/08)
+
+\eightpoint\noindent
+Linn\'e, Carl von (= Linn\ae us, Carolus), 325.
+
+\bugonpage C355, right column (02/29/08)
+
+\eightpoint\noindent
+\llap{*}|save|, $\underline{155}$--$\underline{156}$, {\it160}, 173,
+  {\it178}, 180, 218,\par
+\noindent\qquad{\it236}, {\it244}, {\it296}, 299.
+
+% Volume D
+\def\\#1{\hbox{\it#1\/\kern.05em}} % italic type for identifiers
+\def\to{\mathrel{.\,.}} % double dot, used only in math mode
+
+\bugonpage Dv, page number change (12/27/11)
+
+\eightpoint\noindent[For consistency with Volumes A, C, and E, the
+preface now begins on page v instead of page~vii. This change was first
+made in the sixth printing.]
+
+\bugonpage Dv {(formerly Dvii)}, bottom two lines (01/06/14)
+
+\eightpoint\noindent
+corporates all of those changes.
+I~now believe that the final bug was discovered on 03~June 2008,
+and removed in version 2.7182818.
+The finder's fee has converged to \$327.68.
+
+\bugonpage Dxiii {(formerly Dxv)}, line $-7$ (12/27/11)
+
+\ninepoint\noindent
+Format specs have no effect on the corresponding Pascal program, but they
+do influence\cutpar
+
+\hsize=35pc
+\parindent=1em
+
+\bugonpage D2, line $-17$ (01/03/14)
+
+\ninepoint\noindent
+{\bf define} $\\{banner}\equiv\hbox{\tt\char'23}$%
+{\tt This\]is\]METAFONT,\]Version\]2.7182818\char'23}\quad
+$\{\,$printed when \MF\ starts$\,\}$
+
+\bugonpage D2, lines 4 and 5 from the bottom (12/23/02)
+
+\tenpoint\noindent
+types; there are no `{\bf var}' parameters, except in the case of files
+or in the system-dependent \\{paint\_row} procedure;
+there are no tag fields on variant records; there are no \\{real} variables;
+no procedures are declared local to other procedures.)
+
+\bugonpage D16, new paragraph to follow line 26 (06/25/04)
+
+The first line is special also because it may be read before \MF\ has
+input a base file. In such cases, normal error messages cannot yet
+be given. The following code uses concepts that will be explained later.
+(If the Pascal compiler does not support non-local {\bf goto}, the
+statement `{\bf goto} \\{final\_end}' should be replaced by something that
+quietly terminates the program.)
+
+\bugonpage D22, line 26 (09/11/07)
+
+\noindent
+ASCII codes $[\Oct{60}\to\Oct{71},%
+\Oct{136},\Oct{141}\to\Oct{146}]$
+must be printable.
+
+\bugonpage D31, line 29 (06/25/04)
+
+\noindent
+This is the only nontrivial {\bf goto}  statement in the
+whole program. It is used when there is no\cutpar
+
+\bugonpage D42, replacement for lines 8--13 (12/23/02)
+
+\tenpoint\noindent\quad
+Notice that if 64-bit integer arithmetic were available,
+we could simply compute $(2^{29}*p+\nobreak q)\allowbreak\,
+\hbox{\bf div}\,(2*q)$.
+But when we are restricted to Pascal's 32-bit arithmetic we
+must either resort to multiple-precision maneuvering
+or use a simple but slow iteration. The multiple-precision technique
+would be about three times faster than the code adopted here, but it
+would be comparatively long and tricky, involving about sixteen
+additional multiplications and divisions.
+
+\bugonpage D43, line 20 (12/23/02)
+
+\tenpoint\noindent
+language or 64-bit substitute is advisable.
+
+\bugonpage D44, lines 24--26 (12/23/02)
+
+\tenpoint\noindent\quad
+Once again it is a good idea to use 64-bit arithmetic if
+possible; otherwise \\{take\_scaled} will use more than 2\% of the running time
+when the Computer Modern fonts are being generated.
+
+\bugonpage D58, line 16 from the bottom (06/25/04)
+
+\ninepoint\noindent
+\hskip5em{\bf if\/} $\\{j\_random}=0$ {\bf then} \\{new\_randoms}
+ {\bf else} \\{decr}(\\{j\_random})
+
+\bugonpage D63, line 21 (06/25/04)
+
+Locations of \\{mem} between \\{mem\_min} and \\{mem\_top} may be dumped as
+part
+of preloaded base\cutpar
+
+\bugonpage D75, line 13 (06/25/04)
+
+\ninepoint\noindent
+\quad{\bf define} $\\{fi\_or\_else}=2$\quad$\{\,$delimiters for conditionals
+  ({\bf elseif\/}, {\bf else}, {\bf fi})$\,\}$
+
+\bugonpage D76, line 5 (06/25/04)
+
+\ninepoint\noindent
+\quad{\bf define} $\\{type\_name}=30$\quad$\{\,$declare a type
+  ({\bf numeric}, {\bf pair}, etc.)$\,\}$
+
+\bugonpage D77, line 16 (06/25/04)
+
+\ninepoint\noindent
+\quad{\bf define} $\\{lig\_kern\_token}=76$\quad$\{\,$the operators
+  `{\bf kern}' and `\.{=:}' and `\.{=:\char'174}', etc.$\,\}$
+
+\bugonpage D98, bottom two lines (06/25/04)
+
+\noindent
+They consist of zero or more parameter tokens followed
+by a code for the type of macro.
+
+\bugonpage D101, line 3 (06/25/04)
+
+\noindent
+\MF\ user assigns a type to a variable like \.{x20a.b} by saying, for
+example, `\.{boolean} \.{x[]a.b}'.
+
+\bugonpage D102, lines 10--16 (06/25/04)
+
+\noindent
+variable that is relevant
+when no attributes are attached to the parent. The \\{attr\_head} node
+has the fields of either
+a value node, a subscript node, or an attribute node, depending on what
+the parent would be if it were not structured; but the subscript and
+attribute fields are ignored, so it effectively contains only the data of
+a value node. The \\{link} field in this special node points to an attribute
+node whose \\{attr\_loc} field is zero; the latter node represents a collective
+subscript `\.{[]}' attached to the parent, and its \\{link} field points to
+the first non-special attribute node (or to \\{end\_attr} if there are none).
+
+\bugonpage D102, lines 7 and 8 from the bottom (06/25/04)
+
+\noindent
+$\\{subscr\_head}(\\{q1})=\\{qq1}$;
+\\{qq} is a three-word ``attribute-as-value'' node with
+$\\{type}(\\{qq})=\break\\{numeric\_type}$
+(assuming that \.{x5} is numeric, because \\{qq} represents `\.{x[]}'
+with no further\break
+ attributes), $\\{name\_type}(\\{qq})=\\{structured\_root}$,
+$\\{attr\_loc}(\\{qq})=0$, $\\{parent}(\\{qq})=p$,\cutpar
+
+\bugonpage D103, line 6 (06/25/04)
+
+\noindent
+The value of variable \.{x20b}
+appears in node~$\\{qqq2}=\\{link}(\\{qqq1})$, as you can well imagine.
+Similarly, the value of `\.{x.a}' appears in node $\\{q2}=\\{link}(\\{q1})$,
+where $\\{attr\_loc}(\\{q2})=h(a)$ and $\\{parent}(\\{q2})=p$.
+
+\bugonpage D114, line 12 (06/25/04)
+
+\noindent
+\qquad Such save stack entries are generated by {\bf save} commands.
+
+\bugonpage D120, line 3 (06/25/04)
+
+\ninepoint\noindent
+[delete the line `The code here \dots', since the
+ code {\it doesn't\/} use the stated fact]
+
+\bugonpage D126, line 10 (06/25/04)
+
+\tenpoint\noindent
+If $\theta_0$ is supposed to have a given value $E_0$, we simply
+define $C_0=1$, $D_0=0$, and $R_0=E_0$.\cutpar
+
+\bugonpage D138, line 11 from the bottom (10/26/06)
+
+\tenpoint\noindent
+for the bisected interval are $z'_0=z_0$
+and $z''_0=z_0+(Z'_1+Z'_2+\cdots+Z'_n)/2^{l+1}$.
+
+\bugonpage D142, line 3 (06/25/04)
+
+\tenpoint\noindent
+out to hold if and only if $x_0\le x_1$ and $x_2\le x_3$, and either
+$x_1\le x_2$ or $(x_1-x_2)^2\le(x_1-x_0)(x_3-x_2)$.\cutpar
+
+\bugonpage D142, line 8 (10/26/06)
+
+\tenpoint\noindent\quad
+For example, if we start with $(x_1-x_0,x_2-x_1,x_3-x_2)=
+(X_1,X_2,X_3)=(7,-16,39)$, the\cutpar
+
+\bugonpage D142, lines 21--23 (06/25/04)
+
+\tenpoint\noindent
+monotonic
+cubic, then $B(x_0,x_1,x_2,x_3;{1\over2})$ is always between
+$.06[x_0,x_3]$ and $.94[x_0,x_3]$; and it is impossible for $\bar x$
+to be within~$\epsilon$ of such a number. Contradiction!
+(The constant .06 is actually $(2-\sqrt3\,)/4$; the worst case
+occurs for polynomials like $B(0,2-\sqrt3,1-\sqrt3,3;t)$.)
+
+\bugonpage D177, line 18 (06/25/04)
+
+\ninepoint\noindent
+$\\{cur\_x},\\{cur\_y}$: \\{scaled};\quad$\{\,$outputs of \\{skew},
+ \\{unskew}, and a few other routines$\,\}$
+
+\bugonpage D182, lines 27--29 (06/25/04)
+
+\noindent
+{\bf399.\quad}If
+ the segment numbers on the cycle are $t_1$, $t_2$, \dots, $t_m$,
+and if $m\le\\{max\_quarterword}$,
+we have $t_{k-1}\le t_k$ except for at most one value of~$k$. If there are
+no exceptions, $f$ will point to $t_1$; otherwise it will point to the
+exceptional~$t_k$.
+
+\bugonpage D184, line 18 (12/21/02)
+
+\ninepoint\noindent
+\qquad\\{chopped}: \\{integer};\quad
+$\{\,$positive if data truncated, negative if data dangerously large$\,\}$
+
+\bugonpage D184, line 25 (12/21/02)
+
+\ninepoint\noindent
+\quad{\bf if\/} $(\\{internal}[\\{autorounding}]>0)\land(\\{chopped}=0)$
+ {\bf then} \\{xy\_round};
+
+\bugonpage D184, line 27 (12/21/02)
+
+\ninepoint\noindent
+\quad{\bf if\/} $(\\{internal}[\\{autorounding}]>\\{unity})\land
+ (\\{chopped}=0)$  {\bf then} \\{diag\_round};
+
+\bugonpage D184, line 32 (12/21/02)
+
+\ninepoint\noindent
+\qquad{\bf if\/} $(\\{internal}[\\{autorounding}]\le0)\lor(\\{chopped}\ne0)$
+ {\bf then} \\{print\_spec}({\tt\char`",\]after\]subdivision\char`"})
+
+\bugonpage D185, lines 15--19 (12/21/02)
+
+\ninepoint\noindent
+\quad{\bf define} \\{procrustes}({\tt\char`#})${}\equiv{}${\bf if\/}
+  $\\{abs}(\.\#)\ge\\{dmax}$ {\bf then}\par\noindent
+\qquad\qquad\quad{\bf if\/} $\\{abs}(\.\#)>\\{max\_allowed}$ {\bf then}\par
+\noindent\qquad\qquad\qquad{\bf begin} $\\{chopped}\gets1$;\par\noindent
+\qquad\qquad\qquad{\bf if\/} $\.\#>0$ {\bf then} $\.\#\gets\\{max\_allowed}$
+  {\bf else} $\.\#\gets-\\{max\_allowed}$;\par\noindent
+\qquad\qquad\qquad{\bf end}\par\noindent
+\qquad\qquad\quad{\bf else if\/} $\\{chopped}=0$ {\bf then}
+  $\\{chopped}\gets-1$
+
+\bugonpage D185, old line 22 (12/21/02)
+
+\ninepoint\noindent
+\quad$p\gets\\{cur\_spec}$; $k\gets1$; $\\{chopped}\gets0$;
+ $\\{dmax}\gets\\{half}(\\{max\_allowed})$;
+
+\bugonpage D185, old line 28 (12/21/02)
+
+\ninepoint\noindent
+\quad{\bf if\/} $\\{chopped}>0$ {\bf then}
+
+\bugonpage D196, lines 3--8 (06/25/04)
+
+The first job is to fix things so that $x(t)$ plus the horizontal
+pen offset is an integer multiple of the
+current ``granularity'' when the derivative $x'(t)$ crosses through zero.
+The given cyclic path contains regions where $x'(t)\ge0$ and regions
+where $x'(t)\le0$. The \\{quadrant\_subdivide} routine is called into action
+before any of the path coordinates have been skewed, but some of them
+may have been negated. In regions where $x'(t)\ge0$ we have $\\{right\_type}=%
+\\{first\_octant}$ or $\\{right\_type}=\\{eighth\_octant}$; in regions where
+$x'(t)\le0$,
+we have $\\{right\_type}=\\{fifth\_octant}$ or $\\{right\_type}=\\{fourth%
+\_octant}$.
+
+\bugonpage D196, lines 15 and 16 (06/25/04)
+
+\noindent
+current pen might be unsymmetric in such a way that $x$ coordinates
+should round dif-\break ferently in different parts of the curve.
+These considerations imply that round$(x_0)$\cutpar
+
+\bugonpage D200, line 4 (06/25/04)
+
+\noindent
+and that there are similar ways to address other important offsets.\par
+\smallskip\ninepoint
+[Also delete the definitions of \\{north\_south\_edge}, etc.,
+on lines 11--15; those definitions are never used.]
+
+\bugonpage D212, line 18 (06/25/04)
+
+\noindent
+at $(x_0,y_0)$ and ends at $(x_1,y_1)$, it's possible to
+prove (by induction on the length of the truncated\cutpar
+
+\bugonpage D216, bottom line (06/25/04)
+
+\noindent
+we list it twice (with coordinates
+interchanged, so as to make the second octant look like\cutpar
+
+\bugonpage D217, lines 2--10 (06/25/04)
+
+\noindent
+$$\tabskip\centering
+\halign to\hsize{$\hfil#\;\mapsto\;{}$\tabskip=0pt&
+$#\hfil$&\quad in the #\hfil\tabskip\centering\cr
+w_2\;w_2\;w_2&(-5,6)\;(-5,6)\;(-5,6)\cr
+\noalign{\vskip\belowdisplayskip
+\vbox{\noindent\strut as the list of transformed and skewed offsets to use
+when curves that travel in the second octant. Similarly, we will have\strut}
+\vskip\abovedisplayskip}
+w_2\;w_2\;w_2&(7,-6)\;(7,-6)\;(7,-6)&third;\cr
+w_2\;w_2\;w_3\;w_3&(-7,1)\;(-7,1)\;(-3,2)\;(-3,2)&fourth;\cr
+w_3\;w_3\;w_3&(3,-2)\;(3,-2)\;(3,-2)&fifth;\cr
+w_3\;w_3\;w_0\;w_0&(-3,1)\;(-3,1)\;(1,0)\;(1,0)&sixth;\cr
+w_0\;w_0\;w_0&(1,0)\;(1,0)\;(1,0)&seventh;\cr
+w_0\;w_0\;w_0&(-1,1)\;(-1,1)\;(-1,1)&eighth.\cr}$$
+
+\bugonpage D218, lines 2 and 3 (06/25/04)
+
+\noindent
+count followed by pointers to the eight offset lists, followed
+by an indication of the pen's range of values.
+
+\bugonpage D218, line 15 (06/25/04)
+
+The \\{link} field of a pen header node should be \\{null} if and only if
+the pen is a single point.
+
+\bugonpage D227, line 11 (06/25/04)
+
+\noindent
+\\{endpoint}. The cubics all have
+monotone-nondecreasing $x(t)$ and $y(t)$.
+
+\bugonpage D228, lines 4--7 from the bottom (06/25/04)
+
+\noindent
+In odd-numbered octants, the numerator and denominator of this fraction
+will be nonnegative; in even-numbered octants they will both be nonpositive.
+Furthermore we always have $0=s_0\le s_1\le\cdots\le s_n=\infty$. The goal of
+\\{offset\_prep} is to find an offset index~$k$ to associate with
+each cubic, such that the slope $s(t)$ of the cubic satisfies
+
+\bugonpage D231, line 7 (06/25/04)
+
+\ninepoint\noindent
+\quad{\bf if\/} $\\{abs}(\\{du})\ge\\{abs}(\\{dv})$ {\bf then}\quad $\{\,
+ s_{k-1}\le1$ or $s_k\le1\,\}$
+
+\bugonpage D231, line 16 (06/25/04)
+
+\noindent
+and return towards $s_{k-1}$ or $s_k$,
+respectively, yielding another solution of $(*)$.
+
+\bugonpage D246, line 4 from the bottom (06/25/04)
+
+\noindent
+dinate fields. Hence, for example,
+the point $\bigl($$\\{x\_coord}(p)-\\{left\_v}(q),\\{y\_coord}(p)+%
+\\{right\_u}(p)$$\bigr)$
+also\cutpar
+
+\bugonpage D248, lines 14 and 15 (01/06/14)
+
+\noindent
+the $x$-axis at the point
+$\bigl((a^2-b^2)\sin\theta\cos\theta/\rho\bigr)+i\rho$, where
+\vadjust{\vskip1pt}%
+$\rho=\sqrt{(a\sin\theta)^2+(b\cos\theta)^2}$. It reaches
+furthest to the right of~the $y$-axis at the point
+$\sigma+i(a^2-b^2)\sin\theta\cos\theta/\sigma$, where
+$\sigma=$\cutpar
+
+\bugonpage D248, line 24 (06/25/04)
+
+\ninepoint\noindent
+\qquad{\bf else begin} $\\{beta}\gets\\{minor\_axis}$;
+ $\\{gamma}\gets\\{major\_axis}$;
+ $\\{theta}\gets0$;
+
+\bugonpage D251, line 1 (01/06/14)
+
+\noindent
+{\bf536.\quad}Only the coordinates need to be copied, not the class numbers
+and other stuff. At this point either $\\{link}(p)$ or
+$\\{link}(\\{link}(p))$ is \\{null}.
+
+\bugonpage D251, line 10 (01/06/14)
+
+\ninepoint\noindent
+\\{done1}: {\bf if\/} $(\\{link}(p)\ne\\{null})$ {\bf then}
+$\\{free\_node}(\\{link}(p),\\{knot\_node\_size})$;\hfil\break
+\null\quad$\\{link}(p)\gets s$;
+$\\{beta}\gets-\\{y\_coord}(h)$;
+
+\bugonpage D256, line 2 from the bottom (06/25/04)
+
+\noindent
+we have $2^lu_{\min}=2^lu_0+U_{\min}$, etc.; the condition for overlap
+reduces to
+
+\bugonpage D261, line 5 (06/25/04)
+
+\ninepoint\noindent
+\\{tol}: \\{integer};\quad$\{\,$bound on the uncertainty in the overlap test$\,\}$
+
+\bugonpage D262, lines 26 and 27 (06/25/04)
+
+\ninepoint\noindent
+\qquad\quad$\\{uv}\gets\\{uv}+\\{int\_packets}$;\quad$\{\,$switch
+   from \\{l\_packets} to \\{r\_packets}$\,\}$\par\noindent
+\qquad\quad$\\{decr}(\\{cur\_tt})$;
+ $\\{xy}\gets\\{xy}-\\{int\_packets}$;\quad$\{\,$switch
+   from \\{r\_packets} to \\{l\_packets}$\,\}$
+
+\bugonpage D262, line 11 from the bottom (06/25/04)
+
+\ninepoint\noindent
+\qquad$\\{xy}\gets\\{xy}+\\{int\_packets}$;\quad$\{\,$switch
+   from \\{l\_packets} to \\{r\_packets}$\,\}$
+
+\bugonpage D274, line 15 from the bottom (06/25/04)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin if\/} $\\{serial\_no}>\\{el\_gordo}-\\{s\_scale}$
+  {\bf then}\par\noindent
+\qquad\qquad\quad$\\{overflow}(\.{"independent\]variables"},
+     \\{serial\_no}\mathbin{\hbox{\bf div}}\\{s\_scale})$;\par\noindent
+\qquad\qquad$\\{type}(\#)\gets\\{independent}$;
+ $\\{serial\_no}\gets\\{serial\_no}+\\{s\_scale}$;
+ $\\{value}(\#)\gets\\{serial\_no}$;
+
+\bugonpage D309, line 21 (06/25/04)
+
+\noindent
+{\bf670.\quad}We go to \\{restart} instead of to \\{switch},
+because we might enter \\{token\_state} after the error\cutpar
+
+\bugonpage D314, line 6 from the bottom (06/25/04)
+
+\noindent
+\\{macro\_def} or \\{iteration}).
+
+\bugonpage D330, line 1 (06/25/04)
+
+\noindent
+{\bf728.\quad}A {\bf suffix} or {\bf text} parameter will have been scanned as
+a token list pointed to by \\{cur\_exp},\cutpar
+
+\bugonpage D354, lines 15 and 16 from the bottom (06/25/04)
+
+\noindent\hangindent 3em
+$\\{cur\_type}=\\{unknown\_boolean}$ means that \\{cur\_exp} points to a
+capsule node that is in
+a ring of equivalent booleans whose value has not yet been defined.
+
+\bugonpage D354, lines 11 and 12 from the bottom (06/25/04)
+
+\noindent\hangindent 3em
+$\\{cur\_type}=\\{unknown\_string}$ means that \\{cur\_exp} points to a
+capsule node that is in
+a ring of equivalent strings whose value has not yet been defined.
+
+\bugonpage D354, lines 7 and 8 from the bottom (06/25/04)
+
+\noindent\hangindent 3em
+$\\{cur\_type}=\\{unknown\_pen}$ means that \\{cur\_exp} points to a
+capsule node that is in
+a ring of equivalent pens whose value has not yet been defined.
+
+\bugonpage D355, lines 1 and 2 (06/25/04)
+
+\noindent\hangindent 3em
+$\\{cur\_type}=\\{unknown\_path}$ means that \\{cur\_exp} points to a
+capsule node that is in
+a ring of equivalent paths whose value has not yet been defined.
+
+\bugonpage D355, lines 5 and 6 (06/25/04)
+
+\noindent\hangindent 3em
+$\\{cur\_type}=\\{unknown\_picture}$ means that \\{cur\_exp} points to a
+capsule node that is in
+a ring of equivalent pictures whose value has not yet been defined.
+
+\bugonpage D355, lines 21 and 22 (06/25/04)
+
+\noindent
+$\\{cur\_type}=\\{token\_list}$ means that \\{cur\_exp} points to a linked list
+of tokens.
+
+\bugonpage D356, lines 2--3 (06/25/04)
+
+\noindent
+nodes have $\\{name\_type}=\\{capsule}$,
+and their \\{type} field is one of the possibilities for \\{cur\_type}
+listed above.
+Also $\\{link}\le\\{void}$ in capsules that aren't part of a token list.
+
+\bugonpage D368, line 13 (06/25/04)
+
+\ninepoint\noindent
+\qquad\\{my\_var\_flag}: $0\to\\{max\_command\_code}$;\quad$\{\,$initial
+  value of \\{var\_flag}$\,\}$
+
+\bugonpage D378, line 9 from the bottom (06/25/04)
+
+\ninepoint\noindent
+\qquad\quad{\bf begin} $\\{cur\_type}\gets\\{known}$;
+ $\\{cur\_exp}\gets0$;
+ $\\{free\_node}(q,\\{dep\_node\_size})$;
+
+\bugonpage D380, line 12 (06/25/04)
+
+\ninepoint\noindent
+\qquad\qquad{\bf begin} $\\{type}(r)\gets\\{known}$;
+ $\\{value}(r)\gets0$;
+ $\\{free\_node}(p,\\{dep\_node\_size})$;
+
+\bugonpage D390, lines 2 and 3 (06/25/04)
+
+\noindent
+by a previous operation. We must maintain
+the value of $\\{right\_type}(q)$ in cases such as\break
+`|..{curl2}z{0,0\}..|'.
+
+\bugonpage D437, line 1 (06/25/04)
+
+\noindent
+{\bf996.\quad}And \\{do\_assignment} is similar to \\{do\_equation}:
+
+\bugonpage D439, line 10 becomes two lines (06/25/04)
+
+\ninepoint\noindent
+\qquad{\bf begin} $\\{nonlinear\_eq}(v,\\{cur\_exp},\\{false})$;
+  $\\{cur\_type}\gets t$;
+  {\bf goto} \\{done};
+
+\bugonpage D443, line 11 (06/25/04)
+
+\ninepoint\noindent
+\\{done}: {\bf if\/} $\\{eq\_type}(x)\mathbin{\hbox{\bf mod}}\\{outer\_tag}
+  \ne\\{tag\_token}$ {\bf then}
+  $\\{clear\_symbol}(x,\\{false})$;
+
+\bugonpage D452, line 9 (06/25/04)
+
+\noindent
+though they don't necessarily correspond to primitive tokens.
+
+\bugonpage D476, line 12 from the bottom (06/25/04)
+
+\ninepoint\noindent
+\quad{\bf if\/} $\\{nl}-\\{skip\_table}[c]>128$ {\bf then}
+
+\bugonpage D483, line 7 (06/25/04)
+
+\ninepoint\noindent
+\quad$\\{max\_tfm\_dimen}\gets16\ast\\{internal}[\\{design\_size}]-1
+  -\\{internal}[\\{design\_size}]\mathbin{\hbox{\bf div}}\Oct{10000000}$;
+
+\bugonpage D483, lines 15--17 (06/25/04)
+
+\ninepoint\noindent
+\qquad{\bf if\/} $x>0$ {\bf then}
+  $x\gets\\{max\_tfm\_dimen}$ {\bf else}
+  $x\gets-\\{max\_tfm\_dimen}$;\par\noindent
+\qquad{\bf end};\par\noindent
+\quad$x\gets\\{make\_scaled}(x\ast16,\\{internal}[\\{design\_size}])$;
+
+\bugonpage D496, line 2 (06/25/04)
+
+\noindent
+a pointer to
+an edge structure. Its mission is to describe the positive pixels
+in \.{GF} form,\cutpar
+
+\bugonpage D500, line 16 (06/25/04)
+
+\ninepoint\noindent
+\quad$\\{selector}\gets\\{old\_setting}$;
+ $\\{gf\_out}(\\{cur\_length})$;
+ $\\{gf\_string}(0,\\{make\_string})$;
+ $\\{decr}(\\{str\_ptr})$;
+
+\bugonpage D506, lines 8--10 (06/25/04)
+
+\noindent
+\MF\ it says,
+for example, `\.{(preloaded base=plain 1984.2.29)}', showing the year,
+month, and day that the base file was created. We have $\\{base\_ident}=0$
+before \MF's tables are loaded.
+
+\bugonpage D514, line 14 from the bottom (06/25/04)
+
+\noindent
+\.{CMMF}, should also be provided for commonly used bases such as \.{cmbase}.
+
+% volume E
+\hsize=29pc
+
+\newbox\shorthyf \setbox\shorthyf=\hbox{-\kern-.05em}
+\mathchardef\period=`\.
+{\catcode`\-=\active \global\def-{\copy\shorthyf\mkern3.9mu}
+ \catcode`\.=\active \global\def.{\period\mkern3mu}}
+\def\8#1{\mathrel{\mathcode`\.="8000 \mathcode`\-="8000
+  #1\unkern}} % `..' and `--'
+
+\bugonpage E1, line 3 (01/06/06)
+
+\tenpoint\noindent
+Zillions of alphabets can be generated by the programs in this book.
+All\cutpar
+
+\bugonpage E6, lines 16--19 (12/29/04)
+
+\textindent\bull
+ {\it square\_dots\/} tells whether dots should be square, not rounded;\smallskip
+\textindent\bull
+ {\it hefty\/} tells whether weight-reducing strategies should be used;\smallskip
+\textindent\bull\hangindent\parindent
+ {\it monospace\/} tells whether the characters should all be forced to
+ have the same width;
+
+\bugonpage E7, line 11 (12/21/02)
+
+\ninepoint\indent
+\\{hair}, \\{vair}, \\{stem}, \\{curve}, \\{ess}, \\{flare}, \\{dot\_size},
+ \\{bar}, \\{slab},
+
+\bugonpage E7, line 14 (12/21/02)
+
+\ninepoint\indent
+\\{crisp}, \\{tiny}, \\{fine};
+\medskip\noindent
+and \\{thin\_join} should not be less than \\{fine}.
+
+\bugonpage E19, line 19 (11/07/01)
+
+\tenpoint
+\line{\\{cap\_notch\_cut}\hskip 0pt plus1.5fil46/36\hfil31/36\hfil25/36\hfil
+24/36\hfil22/36\hskip0pt plus3fil25/36}
+
+\bugonpage E41, line 8 (12/21/02)
+
+\ninepoint\noindent\mathchardef\AM="2026 % ampersand
+\quad$\\{extra\_endchar}\gets\\{extra\_endchar}\AM
+ \.{\char`"charcode:=charcode+code\char`\_offset;"}$;
+
+\bugonpage E53, line 7 (12/21/02)
+
+\def\frac#1/#2{\leavevmode\kern.1em
+  \raise.5ex\hbox{\the\scriptfont0 #1}\kern-.1em
+  /\kern-.15em\lower.25ex\hbox{\the\scriptfont0 #2}}
+\ninepoint\noindent
+{\bf numeric} \\{mid\_thickness};
+             $\\{mid\_thickness}={\rm Vround}$ \frac1/3[$\\{vair},\\{stem}$];
+
+\bugonpage E125, line 6 from the bottom (07/10/05)
+
+\ninepoint\noindent
+$\\{top}\,y_1=\\{top}\,y_6=h$; $z_2=.5[z_3,z_1]+\\{bend}$;
+
+\bugonpage E125, line 3 from the bottom (07/10/05)
+
+\ninepoint\noindent
+{\bf draw} $z_1-\\{flourish\_change}\{\\{up}\}+(0,.15\\{asc\_height})
+ \{\\{up}\}$\par
+\line{\quad$\8{...}\{\\{right}\}(z_1+(2u,0))\8{---}z_6\8{...}\{\\{down}\}z_7$;
+ \hfil\% upper bar}
+
+\bugonpage E146, also pages 164 and 540 (02/08/03)
+
+\eightpoint\noindent
+[The labels on the new illustrations of beta, omega, and spadesuit
+are too large, and the resolution of the shapes is too small.]
+
+\bugonpage E147, line 11 from the bottom (04/23/04)
+
+\ninepoint\noindent
+$x_0=x_1=x_9$; $\\{lft}\,x_{0r}={\rm hround}(1.5u-.5\\{hair})$;
+$x_2=x_4=x_6=x_8=.5w-.25u$;
+
+\bugonpage E147, line 8 from the bottom (04/23/04)
+
+\ninepoint\noindent
+$y_5=.5[y_4,y_6]$; $\\{top}\,y_{6r}-\\{bot}\,y_{4r}=\\{vstem}+\\{eps}$;
+ $\\{bot}\,y_{8r}=-\\{oo}$; $y_7=y_9=.55[y_6,y_8]$;
+
+\bugonpage E149, line 8 from the bottom (04/23/04)
+
+\ninepoint\noindent
+$y_5+.1\\{x\_height}=y_7=.5[y_6,y_8]$; $\\{bot}\,y_{6r}=-\\{oo}$;
+
+\bugonpage E157, line 11 (02/29/08)
+
+\ninepoint\noindent
+\line{{\bf filldraw} $z_{1l}\8{--}z_{2l}\8{...}(x_3,y_{2l})\8{...}z\8{--}
+  z_{1r}\8{--}\rm cycle$;\hfil\% stem}
+
+\bugonpage E161, line 7 from the bottom (04/23/04)
+
+\ninepoint\noindent
+$\\{top}\,y_{1r}=\\{x\_height}+\\{oo}$; $y_2=y_4=.5[y_1,y_3]$;
+ $\\{bot}\,y_{3r}=-\\{oo}$;
+
+\bugonpage E209, line 3 (12/29/04)
+
+\ninepoint
+\rightline{\% This lowercase italic alphabet was prepared by D. E. Knuth
+ in December, 1979,}
+
+\bugonpage E377, lines 3 and 4 from the bottom (12/22/02)
+
+\ninepoint\noindent
+\qquad {\bf path} \\{p\_}; $\\{p\_}=z_{\$\$l}\{z_{@1}-z_{\$\$l}\}\8{...}
+ \\{darkness}[z_{@1},.5[z_{@2},z_{\$\$l}]]\8{...}z_{@2}$\par\noindent
+\qquad\quad$\8{---}z_{\$l}\8{--}z_{\$r}\8{--}z_{@0}\8{--}z_{\$\$r}\8{--}%
+ {\rm cycle}$;\par\noindent
+\qquad{\bf if\/} $(y_{\$\$}>y_\$) \ne ({\rm ypart}\,\hbox{\bf precontrol}\,1
+  \,\hbox{\bf of\/}\,\\{p\_} > {\rm ypart}\,\hbox{\bf postcontrol}\,1\,
+  \,\hbox{\bf of\/}\,\\{p\_})$:\par\noindent
+\qquad\quad$\\{p\_}=z_{\$\$l}\{z_{@1}-z_{\$\$l}\}\8{...}
+ \\{darkness}[z_{@1},.5[z_{@2},z_{\$\$l}]]$\par\noindent
+\qquad\qquad$\8{---}z_{\$l}\8{--}z_{\$r}\8{--}z_{@0}\8{--}z_{\$\$r}\8{--}%
+ {\rm cycle}$;\ {\bf fi}\par\noindent
+\line{\qquad {\bf filldraw} \\{p\_};\hfil \% arm and beak}
+
+\bugonpage E379, lines 17 and 18 become one line (01/06/14)
+
+\ninepoint\noindent
+{\bf else}: $\\{rt}\,x_{6r}={\rm hround}(w-1.5u)$;
+$y_{6}=y_{5l}+\\{eps};$ {\bf fi}
+
+\bugonpage E379, bottom line of the program (01/06/14)
+
+\def\SH{\raise.7ex\hbox{$\scriptstyle\#$}} % sharp sign for sharped units
+\ninepoint\noindent
+{\bf math\_fit}$(0,\\{ic}\SH-2.5u\SH)$;
+{\bf penlabels}$(0,1,2,3,4,5,6,7)$;
+{\bf endchar};
+
+\bugonpage E489, bottom line (06/25/04)
+
+\ninepoint\noindent
+{\bf labels}$(1,2,3,4,5,6)$; {\bf endchar};\hfil\break
+[Labels `\.5' and `\.6' should also be added to
+ the lower illustration on page E488.]
+
+\bugonpage E545, line 11 from the bottom (12/29/04)
+
+\parindent=36pt
+The most important general routine in |cmbase| is probably the {\it pos}\cutpar
+
+\bugonpage E551, line 3 from the bottom (12/29/04)
+
+\noindent quantities needed in the |calu|
+programs are also established at this time.
+
+
+\bugonpage E577, right column (12/23/02)
+
+\eightpoint\noindent
+\\{p\_}\kern1pt, 305, 377.\par\noindent
+{\bf padded}, 103--111, 117--121, $\underline{549}$.
+
+\bugonpage E578, left column (12/23/02)
+
+\eightpoint\noindent
+{\bf postcontrol}, 347, 377.\par\noindent
+{\bf precontrol}, 347, 377.
+
+\bye
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errata.two b/Master/texmf-dist/doc/generic/knuth-errata/errata.two
new file mode 100644
index 00000000000..74dde877267
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errata.two
@@ -0,0 +1,491 @@
+% More bugs (sigh) in The TeXbook
+
+\input manmac
+\proofmodefalse
+\raggedbottom
+\output{\onepageout{\unvbox255\kern-\dimen@ \vfil}}
+
+\def\rhead{Bugs in {\tensl The \TeX book}, second printing}
+\def\bugonpage#1(#2) \par{\bigbreak\tenpoint
+  \hrule\line{\lower3.5pt\vbox to13pt{}Page #1\hfil(#2)}\hrule\nobreak\medskip}
+
+\noindent This is a list of all corrections made to {\sl The \TeX book\/}
+since the second printing. If your copy doesn't say `{\sl\kern-1pt Second
+printing (October 1984)\/}' on the copyright page, you should also look at
+the previous bug list. In fact, the most important corrections to the
+first printing were discovered first, so they've already been~made.
+
+\bugonpage 23, line 16 (10/13/84)
+
+\tenpoint\indent
+|This is TeX, Version 1.0 (preloaded format=plain 83.7.15)|
+
+\bugonpage 33, line 32 (10/21/84)
+
+The bottom line shows how far \TeX\ has gotten until now in the
+|story|{\parfillskip=0pt\par}
+
+\bugonpage 41, lines 7 and 8 (10/8/85)
+
+\ddanger The twin operations ^|\uppercase||{|\<token list>|}| and
+^|\lowercase||{|\<token list>|}| go through a given token list and convert
+all of the character tokens to their\parfillskip=0pt\enddanger
+
+\bugonpage 57, line 17 (1/6/86)
+
+|dd|\quad didot point ($\rm1157\,dd=1238\,pt$)
+
+\bugonpage 61, lines 17--19 (12/18/85)
+
+\ninepoint\noindent
+|depth|, |em|, |ex|,
+|fil|, |height|, |in|, |l|, |minus|, |mm|, |mu|, |pc|, |plus|,
+|pt|, |scaled|, |sp|, |spread|, |to|, |true|, |width|. ^^{reserved words}
+\ (See Appendix~I for references to the contexts in which each of these is
+recognized as a keyword.)
+
+\bugonpage 67, append a new exercise (1/19/85)
+
+\exno=5 \def\chapno{11}
+\gdef\frac#1/#2{\leavevmode\kern.1em
+  \raise.5ex\hbox{\the\scriptfont0 #1}\kern-.1em
+  /\kern-.15em\lower.25ex\hbox{\the\scriptfont0 #2}}
+
+\ddangerexercise Construct a |\frac| macro such that `|\frac1/2|' yields
+`\frac1/2'.
+
+\bugonpage 130, line 15 (4/17/85)
+
+\beginmathdemo
+|$y'''_3+g'^2$|&y'''_3+g'{}^2\cr
+\endmathdemo
+
+\bugonpage 170, line 5 (5/28/85)
+
+\ninepoint
+\line{tall, unslanted
+letter; and so on. But two of the examples involve corrections that were}
+
+\bugonpage 194, lines 13--15 should be centered better (10/22/84)
+
+\ninepoint
+$$\displaylines{\hfill x\equiv x;\hfill\llap{(1)}\cr
+   \hfill\hbox{if}\quad x\equiv y\quad\hbox{then}\quad
+      y\equiv x;\hfill\llap{(2)}\cr
+   \hfill\hbox{if}\quad x\equiv y\quad\hbox{and}\quad
+      y\equiv z\quad\hbox{then}\quad
+      x\equiv z.\hfill\llap{(3)}\cr}$$
+
+\bugonpage 215, lines 9 and 10 from the bottom (12/23/84)
+
+\ninepoint\noindent
+general format
+is the same as for |\def| and |\gdef|, but \TeX\ blindly expands the tokens
+of the replacement text according to the expansion rules above. For
+example, consider
+
+\bugonpage 233, lines 15--19 (1/19/85)
+
+\medskip
+\settabs\+\indent&10\frac1/2 lbs.\qquad&\it Servings\qquad&\cr
+\+&\negthinspace\it Weight&\it Servings&
+  {\it Approximate Cooking Time\/}*\cr
+\smallskip
+\+&8 lbs.&6&1 hour and 50 to 55 minutes\cr
+\+&9 lbs.&7 to 8&About 2 hours\cr
+\+&9\frac1/2 lbs.&8 to 9&2 hours and 10 to 15 minutes\cr
+\+&10\frac1/2 lbs.&9 to 10&2 hours and 15 to 20 minutes\cr
+
+\bugonpage 236, lines 18--21 (1/19/85)
+
+\ninepoint
+$$\vbox{\openup2pt
+\halign{\hfil\bf#&\quad\hfil\it#\hfil&\quad\hfil#\hfil&
+           \quad\hfil#\hfil&\quad#\hfil\cr
+Squab&Poussin&2&\frac3/4 to 1&Broil, Grill, Roast\cr
+Broiler&Poulet Nouveau&2 to 3&1\frac1/2 to 2\frac1/2&Broil, Grill, Roast\cr
+Fryer&Poulet Reine&3 to 5&2 to 3&Fry, Saut\'e, Roast\cr
+Roaster&Poularde&5\frac1/2 to 9&Over 3&Roast, Poach, Fricassee\cr}}$$
+[This change should also be made at the bottom of page 237.]
+
+\bugonpage 236, fifth-last line (1/19/85)
+
+\ninepoint
+| Squab&Poussin&2&\frac3/4 to 1&Broil, Grill, Roast\cr|
+
+\bugonpage 237, line 25 (10/10/84)
+
+\ninepoint\noindent
+saying `^|\tabskip||=|\<glue>'. For example,
+let's do the poultry table again, but with the{\parfillskip=0pt\par}
+
+\bugonpage 265, bottom line (11/6/85)
+
+[insert a comma after `{\eightss LEONTIEF}'.]
+
+\bugonpage 271, line 8 (11/12/85)
+
+\ninepoint
+\beginsyntax
+<fil unit>\is[fil]\alt<fil unit>[l]
+\endsyntax
+
+\bugonpage 280, lines 7 and 8 (1/8/85)
+
+\ninepoint\noindent
+\<4-bit number>.\enskip
+The specified output stream is opened or closed, for use in |\write|
+commands, as explained in Chapter~21.
+
+\bugonpage 300, lines 5--10 [changed for version 1.3] (11/25/84)
+
+\ninepoint\noindent
+what part of \TeX's memory has become overloaded;
+one of the following fourteen things will be mentioned:
+\begindisplay
+|number of strings|\qquad(names of control sequences and files)\cr
+|pool size|\qquad(the characters in such names)\cr
+|main memory size|\qquad(boxes, glue, breakpoints, token lists,
+  characters, etc.)\cr
+\enddisplay
+
+\bugonpage 300, lines 23--29 [changed for version 1.3] (11/25/84)
+
+\danger If you have a job that doesn't overflow \TeX's capacity, yet
+you want to see just how closely you have approached the limits,
+just set ^|\tracingstats| to a positive value before the end of your
+job. The log file will then conclude with a report on your actual
+usage of the first eleven things named above (i.e., the number of strings,
+\dots, the save size), in that order. ^^{stack positions}
+Furthermore, if you set |\tracingstats| equal to 2~or~more, \TeX\
+will show its current memory usage whenever it
+does a ^|\shipout| command. Such statistics are broken into two
+parts; `|490&5950|' means, for example, that 490 words are being used
+for ``large'' things like boxes, glue, and
+breakpoints, while 5950 words are being used for ``small'' things like
+tokens and characters.
+
+\bugonpage 302, line 14 (10/8/85)
+
+\begintt
+.\tenrm || (ligature ---)
+\endtt
+
+\bugonpage 305, line 26 (12/24/84)
+
+\ninepoint\noindent
+sentable as |^^M|. Asking \TeX\ to |\show\^^M|
+\looseness-1
+produces the response `|>| |\^^M=macro:->\|\]|.|'.
+
+\bugonpage 306, line 10 (7/1/85)
+
+\ninepoint\noindent
+no ``^{explicit kerns},'' and an italic correction is an
+explicit kern.) \ But the italic correction may be too much (especially in an
+italic font); |shelf{|^|\kern||0pt}ful| is often best.
+
+\bugonpage 308, line 25 (3/25/85)
+
+\ninepoint\indent
+|\def\appendroman#1#2#3{\edef#1{\def\noexpand#1{\csname|
+
+\bugonpage 311, insert a new answer (1/19/85)
+
+\ninepoint
+\ansno11.6:
+ |\def\frac#1/#2{\leavevmode\kern.1em|\parbreak
+|\raise.5ex\hbox{\the\scriptfont0 #1}\kern-.1em|\parbreak
+|/\kern-.15em\lower.25ex\hbox{\the\scriptfont0 #2}}|
+
+\smallskip\noindent[This causes answer 12.8 to move to page 312;
+answer 12.16 also moves to page 313.]
+
+\bugonpage 320, lines 17--20 (8/10/85)
+
+\ninepoint
+\ansno17.16:
+ |\def\sqr#1#2{{\vcenter{\vbox{\hrule height.#2pt|\parbreak
+        |        \hbox{\vrule width.#2pt height#1pt \kern#1pt|\parbreak
+        |           \vrule width.#2pt}|\parbreak
+        |        \hrule height.#2pt}}}}|
+
+\bugonpage 327, lines 26--33 (10/22/84)
+
+\ninepoint
+\ansno19.16:
+  |$$\displaylines{\hfill x\equiv x;\hfill\llap{(1)}\cr|\parbreak
+        |   \hfill\hbox{if}\quad x\equiv y\quad\hbox{then}\quad|\parbreak
+        |      y\equiv x;\hfill\llap{(2)}\cr|\parbreak
+        |   \hfill\hbox{if}\quad x\equiv y\quad\hbox{and}\quad|\parbreak
+        |      y\equiv z\quad\hbox{then}\quad|\parbreak
+        |      x\equiv z.\hfill\llap{(3)}\cr}$$|\par\medskip\noindent
+There's also a trickier solution, which begins with
+\begintt
+$$\displaylines{x\equiv x;\hfil\llap{(1)}\hfilneg\cr
+\endtt
+
+\bugonpage 330, line 29 (11/15/85)
+
+\ninepoint\indent
+|\edef\next#1#2{\def#1{\b#2\d}} \next\a\c|
+
+\bugonpage 332, lines 17--24 (1/19/85)
+
+\ninepoint
+\begintt
+\settabs\+\indent&10\frac1/2 lbs.\qquad&\it Servings\qquad&\cr
+\+&\negthinspace\it Weight&\it Servings&
+  {\it Approximate Cooking Time\/}*\cr
+\smallskip
+\+&8 lbs.&6&1 hour and 50 to 55 minutes\cr
+\+&9 lbs.&7 to 8&About 2 hours\cr
+\+&9\frac1/2 lbs.&8 to 9&2 hours and 10 to 15 minutes\cr
+\+&10\frac1/2 lbs.&9 to 10&2 hours and 15 to 20 minutes\cr
+\endtt
+
+\bugonpage 332, lines 33--35 (1/19/85)
+
+\ninepoint\noindent
+proofs. \ (You weren't supposed to think of this,
+but it has to be mentioned.) \ See exercise 11.\fracexno\ for the `|\frac|'
+macro; it's better to say `\frac1/2' than `$1\over2$', in a cookbook.\par
+Another way to treat this table would be to display it in a vbox, instead
+of including a first column whose sole purpose is to specify indentation.
+
+\bugonpage 337, line 28 (11/12/85)
+
+\ninepoint\noindent |\nextnumber|. Quick should put `|\relax|'
+at the end of his macro. \ (The {keywords} |l|,{\parfillskip=0pt\par}
+
+\bugonpage 357, lines 35 and 36 (1/8/85)
+
+\ninepoint\noindent
+|\def\*{\discretionary{\thinspace\the\textfont2\char2}{}{}}|
+
+\bugonpage 357, last two lines (4/17/85)
+
+\ninepoint\noindent
+|\def\pr@m@s{\ifx'\next\let\next\pr@@@s|%
+  | \else\ifx^\next\let\next\pr@@@t|\par\noindent
+|  \else\let\next\egroup\fi\fi \next}|\par\noindent
+|\def\pr@@@s#1{\prim@s} \def\pr@@@t#1#2{#2\egroup}|
+
+\bugonpage 358, lines 8--12 (1/23/85)
+
+\ninepoint\noindent
+|\def\hbar{{\mathchar'26\mkern-9muh}}|\hfil\break\null
+|\def\surd{{\mathchar"1270}}|\hfil\break\null
+|\def\angle{{\vbox{\ialign{$\m@th\scriptstyle##$\crcr|\hfil\break\null
+|      \not\mathrel{\mkern14mu}\crcr \noalign{\nointerlineskip}|\hfil\break\null
+|      \mkern2.5mu\leaders\hrule height.34pt\hfill\mkern2.5mu\crcr}}}}|
+
+\bugonpage 359, lines 7--8 (1/22/85)
+
+\ninepoint\noindent
+|\def\ddots{\mathinner{\mkern1mu\raise7pt\vbox{\kern7pt\hbox{.}}\mkern2mu|%
+\hfil\break\null
+|    \raise4pt\hbox{.}\mkern2mu\raise1pt\hbox{.}\mkern1mu}}|
+
+\bugonpage 360, line 22 (1/22/85)
+
+\ninepoint\noindent
+|  \mkern5mu \raise.6\dimen@\copy\rootbox \mkern-10mu \box0}|
+
+\bugonpage 361, line 3 (3/27/85)
+
+\ninepoint\noindent
+|\def\buildrel#1\over#2{\mathrel{\mathop{\kern0pt #2}\limits^{#1}}}|
+
+\bugonpage 361, lines 19--20 (1/22/85)
+
+\ninepoint\noindent
+|\def\bmod{\mskip-\medmuskip \mkern5mu|\hfil\break\null
+|  \mathbin{\rm mod} \penalty900 \mkern5mu \mskip-\medmuskip}|
+
+\bugonpage 361, line 27 (5/1/85)
+
+\ninepoint\noindent
+|\def\matrix#1{\null\,\vcenter{\normalbaselines\m@th|
+
+\bugonpage 361, bottom line (5/1/85)
+
+\ninepoint\noindent
+|  \null\;\vbox{\kern\ht1\box2}\endgroup}|
+
+\bugonpage 362, line 9 (5/1/85)
+
+\ninepoint\noindent
+|\def\eqalign#1{\null\,\vcenter{\openup1\jot \m@th|
+
+\bugonpage 362, lines 17--29 (8/10/85)
+
+{\parindent=0pt\ninepoint
+|\def\@lign{\tabskip=0pt\everycr={}} % restore inside \displ@y|\par
+|\def|^|\displaylines||#1{\displ@y|\parbreak%
+|  \halign{\hbox to\displaywidth{|%
+ |$\hfil\@lign\displaystyle##\hfil$}\crcr|\parbreak%
+|    #1\crcr}}|
+\smallbreak
+|\def|^|\eqalignno||#1{\displ@y \tabskip=|^|\centering|\parbreak%
+|  \halign to\displaywidth{\hfil$\@lign\displaystyle{##}$\tabskip=0pt|\parbreak%
+|    &$\@lign\displaystyle{{}##}$\hfil\tabskip=\centering|\parbreak%
+|    &\llap{$\@lign##$}\tabskip=0pt\crcr|\parbreak%
+|    #1\crcr}}|\par
+|\def|^|\leqalignno||#1{\displ@y \tabskip=\centering|\parbreak%
+|  \halign to\displaywidth{\hfil$\@lign\displaystyle{##}$\tabskip=0pt|\parbreak%
+|    &$\@lign\displaystyle{{}##}$\hfil\tabskip=\centering|\parbreak%
+|    &\kern-\displaywidth\rlap{$\@lign##$}\tabskip=\displaywidth\crcr|\parbreak%
+|    #1\crcr}}|
+\par}
+
+\bugonpage 363, line 9 (5/12/85)
+
+\ninepoint\noindent
+|\def\footnote#1{\let\@sf=\empty % parameter #2 (the text) is read later|
+
+\bugonpage 364, line 3 (3/23/85)
+
+\ninepoint\noindent
+|\def\plainoutput{\shipout\vbox{\makeheadline\pagebody\makefootline}%|
+
+\bugonpage 364, fifth-last line (9/15/85)
+
+\ninepoint\noindent
+|\def\fmtname{plain}\def\fmtversion{2.0} % identifies the current format|
+
+\bugonpage 399, eighth-last line (2/11/85)
+
+\ninepoint\noindent
+|  \baselineskip=\footnotebaselineskip\noindent\unhbox0\par}|
+
+\bugonpage 401, line 5 (1/29/85)
+
+\ninepoint\noindent
+{|\fontdimen| parameters to qualify as a math symbol font).
+(2)~Set all the font identifiers\parfillskip=0pt\par}
+
+\bugonpage 414, line 10 (12/17/84)
+
+\ninepoint\noindent
+|\font\titlefont=cmssdc40           % titles in chapter openings|
+
+%\bugonpage 420, line 9 (10/3/85)
+%
+%\ninepoint\noindent
+%|\def\AmSTeX{$\cal A\kern-.1667em\lower.5ex\hbox{$\cal M$}\kern-.075em|
+% that change comes under `font data', explained away below
+
+\bugonpage 444, bottom line (1/10/85)
+
+\ninepoint\noindent
+depth $d(z)+v$, consisting
+of box~$x$ followed by an appropriate kern followed by box~$z$.
+
+\bugonpage 461, entry for character codes (11/6/85)
+
+\eightpoint
+Add `{\sl see also\/} category codes'.
+
+\bugonpage 463, entries for {\tt dd}, Didot, and didot (1/6/86)
+
+\eightpoint
+Remove the circumflex accents.
+
+\bugonpage 466, left column (1/19/85)
+
+\eightpoint
+fractions, 67, 139--143, 152, 170, 179,\par
+\qquad 186, 444--445.\par
+\quad huge, 196.\par
+\quad slashed form, 67, 139--140, 233, 236.
+
+\bugonpage 467, index entry for {\tt\char`\\hsize} (6/14/85)
+
+\eightpoint
+Add a reference to page {\it 60}.
+
+\bugonpage 469, index entry for {\tt\char`\\kern} (7/1/85)
+
+\eightpoint
+Add a reference to page {\it 306}.
+
+\bugonpage 469, index entry for kerns (7/1/85)
+
+\eightpoint
+Add a reference to page 306.
+
+\bugonpage 469, new entry (11/12/85)
+
+\eightpoint
+|l| after |fil|, $\underline{271}$, 337.
+
+\bugonpage 469, second line on the right (9/13/85)
+
+\eightpoint
+%\def\LaTeX{L\kern-.25em\raise.7ex\hbox{a}\kern-.05em\TeX} % old style
+{L\kern -.36em\raise.6ex\hbox{\sixrm A}\kern-.15em\TeX}, 137.
+
+\bugonpage 470, index entries for {\tt\char`\\longleftarrow}
+      thru {\tt\char`\\Longrightarrow} (10/5/84)
+
+\eightpoint
+The references to page 358 should be underlined (seven times).
+
+\bugonpage 475, index entry for punctuation in formulas (4/29/85)
+
+\eightpoint
+Add a reference to page 161.
+
+\bugonpage 476, index entry for {\tt\char`\\scriptspace} (8/10/85)
+
+\eightpoint
+Change `445' to `445--446'.
+
+\bugonpage 478, first and last lines (10/11/84)
+
+\noindent Delete the last line in the right-hand column
+(since it appears on page 479), and add the following line
+at the top of the left-hand column (since it was dropped by mistake
+from the second printing):
+
+\smallskip
+\eightpoint styles of math formatting, 140--141, 441--447.
+
+\bugonpage 478, new entry after tabbing (5/28/85)
+
+\eightpoint
+tables, {\sl see\/} alignments, tabbing.
+
+\bugonpage 478, tabskip entries (3/25/85)
+
+\eightpoint\noindent Instead of `237--239' and `237--238' it should say
+`$\underline{237}$--$\underline{239}$' twice.
+
+\bugonpage 481, the entry for {\tt\char`\\widetilde} (9/23/85)
+
+\eightpoint
+Page 359 should be underlined.
+
+\bugonpage 483, lines 16--17 (1/19/85)
+
+|P.O. Box 9506|\parbreak
+|Providence RI 02940-9506, USA.|
+
+\bugonpage 483, lines 22--23 (1/19/85)
+
+P.O. Box 9506\par
+Providence RI 02940-9506, USA.
+
+\bigskip
+\hrule
+\bigskip\noindent\tenrm
+Note: The next printing will use the ``real'' Computer Modern fonts
+instead of the ``almost'' Computer Modern fonts. Therefore many of
+the line breaks will be slightly different. Also, the font-related
+numerical data on pages 27, 29, 66, 75, 76, 79, 88, 98, 99, 112, 113, 310,
+314, 396, 399, 409, 420, and 459 will be different. However, these
+differences need not be listed here, because the old book was correct with
+respect to the old fonts.
+
+\bye
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/errorlog.tex b/Master/texmf-dist/doc/generic/knuth-errata/errorlog.tex
new file mode 100644
index 00000000000..dfb201b7377
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/errorlog.tex
@@ -0,0 +1,2946 @@
+% Appendix to the Errors of TeX paper (updated) 
+% Section numbers now adjusted to TeX 3.0 equivalents
+% NB: tab marks are significant in this file, they signal continuation lines
+%\magnification=\magstephalf
+%\pageno=35
+\input logmac
+* 10 Mar 1978
+L1. Rename a few external variables to make their first six letters unique.
+D2. Initialize \\{escape_char} to $-1$, not 0 [it will be set to the
+	first character input]. @240
+L3. Fix bug: The test `$\\{id}<\O{200}$' was supposed to distinguish one-letter
+	identifiers from longer (packed) ones, but negative values of
+	\\{id} also pass this test. @356
+B4. Fix bug: I wrote `{\bf while} $\alpha\land(\beta\lor\gamma)$' when I meant
+	`{\bf while} $(\alpha\land\beta)\lor\gamma$'. @259
+R5. Initialize the input routines in |INITEX| [at this time a short,
+	separate program not under user control], in case errors occur. @1337
+E6. Don't initialize \\{mem} in |INITEX|, it wastes time. @164
+B7. Change `\\{new_line}' [which denotes a lexical scanning state] to
+	`\\{next_line}' [which denotes
+	\\{carriage_return} and \\{line_feed}] in print commands.
+F8. Include additional test `$\\{mem}[p] \ne 0\; \land$' in \\{check_mem}. @168
+M9. Fix inconsistency between the \\{eq_level} conventions of \\{macro_def} and
+	\\{eq_define}. @277
+# About six hours of debugging time today.
+# |INITEX| appears to work,
+	and the test routine got through \\{start_input},
+	\\{chcode} [the \TeX78 command for assigning a \\{cat_code}],
+	\\{get_next}, and \\{back_input} the first time.
+* 11 Mar 1978
+I10. Insert space before `|(|' on terminal when opening a new file. @537
+F11. Put `$p\gets \\{link}(p)$' into the loop of \\{show_token_list},
+	so that it doesn't loop forever. @292
+L12. Shift the last item found by \\{scan_toks} into the \\{info} field.
+	[With |SAIL| all packing of fields was done by arithmetic operations,
+	not by the compiler.] @474
+B13\>12. Fix the previous bugfix: I shifted by the wrong amount. @474
+I14. Add a feature that prints a warning when the end of a file page occurs within
+	a macro definition or call. [System dependent.] @336
+# Unintended bugs in my test routine [a format intended eventually to typeset
+	{\sl The Art of Computer Programming\/}] helped check out the
+	error recovery mechanisms.
+	For example, I had `|\lft{#}|' instead of `|\lft{##}|' inside a macro,
+	and three cases of improper |{|~and~|}| nesting.
+F15. Add the forgotten case `\\{set_font}:' to \\{eq_destroy}. @275
+C16. Change |\require| to |\input|. @376
+F17. Add code for the case $\\{cur_cmd}=0$ [later known as the case
+	`$\,t\ge\\{cs_token_flag}$'] when scanning a tokenlist. @357
+# That's the first ``big'' error I've spotted so far.
+I18. Introduce a `|d|' option in the error routine, to facilitate debugging. @84
+L19. Assign a floating-point constant \\{ignore_depth} to \\{prev_depth},
+	instead of assigning the integer constant \\{flag}
+	[since \\{prev_depth} is type \\{real} in \TeX78]. @215
+I20. Improve the readability and spacing of \\{show_node_list} output. @182,187
+F21. Set the variable $v$ before using the {\bf case} construction in
+	\\{show_node_list}, because there's one case where $v$ 
+	didn't receive a value [as part of the field unpacking]. @182
+# About seven hours today.
+* 12 Mar 1978
+# One hour to enter yesterday's corrections and recompile.
+# At this point \TeX\ correctly located further unintended syntax errors
+	in |acphdr| [the test file].
+I22. Insert \\{debug_help} into \\{succumb}, giving a chance to look at memory
+	before the system dies. @93
+D23. Use \\{eq_destroy} wherever necessary in \\{unsave}. @283
+L24. Change `$t \gets  (t-1)$ mod 8' to `$t \gets  (t-1)$ land~7' in \\{id_name},
+	since |SAIL| has $-1$~mod~$8 = -1$. [At this time, \\{id_name} is a
+	routine that unpacks control sequence names, according to a scheme
+	that will become obsolete after change \#422.]
+S25. Remove the space that appears at end of paragraph.
+	(I hadn't anticipated that.) @816
+L26. Throw away unwanted \\{line_feed} after getting a \\{carriage_return}
+	in response to \\{in_chr_w} [a system routine for
+	input from the terminal]. @83
+B27. Delete spurious call to \\{flush_list} in \\{end_token_list}. @324
+# Why did I make such a silly mistake?
+F28. Fix bug in \\{get_x_token}: I forgot to say `\\{macro_call}' (which is the
+	main point of that routine)! @380
+# While tracking that bug down, I found out incidentally that kerning is okay.
+# Also \TeX\ correctly caught an error |0p| for |0pt|.
+L29. Fix bug in \\{scan_spec} ({\bf while} instead of {\bf repeat}). @404
+M30. Make the table entries for |\hfill| and |\hskip| consistent with the
+	program conventions. @1058
+L31. Disable unforeseen coercion: When \\{scan_spec} put \\{hsize} on
+	\\{save_stack}, the value changed from \\{real} to \\{integer}. @645
+I32. Use `|*|' instead of `|-1.0|' for running dimensions
+	of rules in \\{show_node_list}. @176
+D33. Clear \\{mem}[\\{head}] to null in \\{push_nest} [in \TeX82, this
+	will be done by \\{get_avail}]. @216
+# A vrule link got clobbered because I forgot to do this.
+I34. Translate ASCII control codes to special form when displaying them. @48,68
+# Ligatures work, but \\{show_node_list} showed them funny.
+F35. Remember to clear parameters off \\{save_stack} in \\{package} routine. @1086
+# About eight hours today.
+* 13 Mar 1978
+D36. Introduce a new variable \\{hang_first} [later the sign of \\{hang_after}]. @849
+E37\>36. Simplify the new code, realizing that if $\\{hang_indent}=0$ then
+	\\{hang_first} is irrelevant. @848
+# Time sharing is very slow today, so I'm mostly reading technical reports while
+	waiting\/ {\bf three hours} for compiler, editor, and loading routine.
+# I'm not counting this as debugging time!
+# (Came back in the evening.)
+P38. Spruce up the comments in the \\{line_break} routine, which appears to be
+	almost working. @813
+D39. Rethink the setting of \\{best_line}; it's 1 too high in many cases.
+	[The final line of a paragraph was handled in a treacherous way.] @874
+D40. Compute proper initialization for
+	\\{prev_depth} when beginning an |\hbox|
+	with a paragraph inside. [This refers to a special `paragraph box'
+	construction, used when an hbox of specified size becomes overfull;
+	\TeX78 doesn't have the concept of internal vertical mode.] @1083
+D41. Also initialize \\{tail} in that case. @1083
+M42. Also put the result of line-breaking into the correct list.
+T43. Fix a typo in the \\{free_node} routine (`\\{link}' not `\\{llink}');
+	by strange chance it had been harmless until today. @130
+F44. Fix bug: \\{post_line_break} forgot to set \\{adjust_tail}. @889
+D45. Update \\{act_width} properly when looking for end of word while
+	line breaking. @866
+B46. Repair the ``tricky'' part of \\{get_node}: I used the \\{info} field
+	when I meant to say \\{llink}. @127
+# Now the |\corners| macro of |acphdr| works! [See |\setcornerrules|
+	in {\sl The \TeX book}, page 417.]
+D47. Reset \\{contrib_tail} properly in \\{build_page}. @995
+T48. Fix typo (|-| for |+|) in computation of \\{page_total}. @1004
+S49. Change the page-breaking logic: \TeX\ reached \\{fire_up} with
+	$\\{best_page_break}=\\{null}$ in one case,
+	since the badness was too bad. @1005
+M50. Perform the operation \\{delete_token_ref}(\\{top_mark}) only when
+	$\\{top_mark}\ne0$. @1012
+F51. Make \\{scan_toks} omit the initial |{| of an |\output| routine. @473
+I52. Insert a comma to make memory usage statistics look better. @639
+# About seven good hours of debugging today.
+# Tomorrow will be first-output day (I hope).
+* 14 Mar 1978
+# (Came in evening after sleeping most of day, to get computer at better time.)
+# (Some day we will have personal computers and will live more normally.)
+# 8:30pm, began to enter corrections to yesterday's problems.
+I53. Issue an error message for non-character in filename or in font name. @771
+I54. Display `|...|' for omitted stuff in \\{show_context} routine. @643
+L55. Watch out for the |SAIL| syntax `$\alpha+\beta\mathbin{\rm lsh}\gamma$';
+	it doesn't shift $\alpha+\beta$ left (only $\beta$). @464
+# That error was very hard to track down; it created a spurious link field
+	and sent $\\{hash}[0]=\null$|\beta| to the scanner!
+# I could have found this bug an hour sooner if I had looked at the correct
+	stack entries for \\{name} and \\{token_type}.
+D56. Show the correct page number when tracing pages before output is shipped. @638
+F57. Remember to nullify a box after using it. @1079
+I58. Issue an error message if\/ |\box255| isn't consumed by the output routine. @1015
+# I'm having trouble with the |BAIL| debugger;
+	it makes an illegal memory reference and dies,
+	when single-stepping past the entry to recursive procedures
+	\\{hlist_out} and \\{vlist_out}.  So I have to reload and be careful
+	to go thru these procedures at high speed.
+P59. Fix bug in comment (memory parameter description said $\ge$ not $\le$). @11
+B60. Fix typo in definition of rule output (said $x,y$ not $\\{x0},\\{y0}$).
+	[This part of the code went away when |DVI| files were introduced.]
+B61. Correct the embarrassing bug in shellsort, where I said `$\le\\{str}[k]$'
+	not `$\le t$'.
+	[The first \TeX\ had to sort all output by vertical position on page.]
+M62. Make \\{start_input} set up \\{job_name} in the form needed by \\{shipout};
+	it uses obsolete conventions. @532,537
+L63. Insert |(| and |)| into the |SAIL| macro definition of \\{new_string}.
+	[This macro was for pre-|DVI| output.]
+M64. Unscramble the parameters of \\{out_rule}:
+	The declaration was $(\\{x0},\\{y0},\\{x1},\\{y1})$
+	while the call was $(\\{x0},\\{x1},\\{y0},\\{y1})$.
+# 4:30am, \TeX's first page is successfully output!
+# (It was `|\titlepage\setcpage1\corners\eject\end|'.)
+* 15 Mar 1978
+# 10:30pm. Today I'm instrumenting the line-breaking routine and putting it
+	through a bunch of tests.
+# (The inserted instrumentation had bugs that won't be mentioned here.)
+C65. Don't abort the job when \\{eq_destroy} redefines a
+	\TeX\ control sequence. @275
+# The first word of a paragraph won't be hyphenated \dots\ so be it!
+T66. Fix the typo in \\{line_break} that spoils the test for
+	`letters in the same font'. @896
+# The effect of that typo was to suppress all hyphenation attempts.
+B67\>25. Replace the space at paragraph end by fillglue, not by zero. @816
+L68. Pack the hyphen character properly into its node. @582
+T69. Fix a typo (`{\tentex\char'30}' for `|+|')
+	in the computation of \\{break_width}. @838
+M70. Change the |\end| maneuver; the present code doesn't end the job,
+	since I forgot that \\{back_input} uses \\{cur_tok}. @1054
+A71. Add a parameter to \\{try_break}, since the width is different at
+	a discretionary hyphen. [This problem will be solved differently in \TeX82,
+	when discretionaries become much more general.] @840
+F72. Bypass kern nodes in pre-hyphenation. @896
+F73. Supply code for the forgotten case `$<$ |"a"|' in pre-hyphenation.
+	[This case was later generalized to a test of \\{lc_code}.] @897
+B74. Change $\\{mem}[q]$ to $\\{prev_break}(q)$ in the
+	reverse-linking loop. @878
+# (Such blunders. Am I getting feeble-minded?)
+A75. Introduce special logic for \\{eject_penalty}; I was wrong
+	to think that forced ejection was exactly like an
+	infinitely negative penalty. @851
+A76. Use $(1+b)^2-p^2$ when computing demerits with $p<0$. @859
+# 6:30am. The line-breaking algorithm appears to be working fine
+	and efficiently.
+	On small measures (about 20 characters per line), it gives overfull boxes
+	instead of spaced out ones. Surprising but satisfactory.
+* 16 Mar 1978
+# 9pm. The plan for tonight is to test page breaking and more paragraphing.
+G77. Insert `|\topskip|' glue at beginning of page. @1001
+I78. Add `|\pausing|' feature. @363
+M79. Fix discrepancy: In \\{make_accent} I called \\{vpackage}
+	with a pointer to the first list item, but \\{vpackage} itself assumes
+	that the parameter is a pointer to that pointer. [The
+	\\{vpackage} of \TeX82 will be different.] @668
+# I checked for other lapses like that. Result: 14 calls OK, 12 NG.
+M80. Create a new temporary list head location, \\{hold_head}, since there's
+	a case where \\{vpackage} is improperly called with
+	parameter \\{temp_head}. [At this time \\{vpackage} uses \\{temp_head}
+	to make a list of all insertions found.] @1014
+# 11:30pm. The machine is tied up again.
+F81. Write code to handle charnodes in vlists; I forgot that I'd decided
+	to allow them. [Later I prohibited them again!] @669
+F82. Combine the page lists before pruning off glue
+	in \\{fire_up}; otherwise the pruning doesn't go far enough. @1017
+B83\>25. Fix typo where line-breaking starts: `\\{fill_glue}' should be
+	`\\{new_glue}(\\{fill_glue})'. @816
+I84. Add |/q| to |xspool| command (cosmetic change). [This changes a system
+	command that causes \TeX\ output to be printed on the Xerox Graphics
+	Printer (XGP), the progenitor of future laser printers;
+	the |/q| option says that the queue of printing requests should be
+	displayed on the user's terminal.] @642
+E85. Don't write a form feed after the last page of output. @642
+# To fix this, I reorganized \\{ship_out}, and it became simpler.
+T86. Correct a typo (`{\tentex\char'30}' for `|+|') in the \\{vlist_node} case
+	within \\{hlist_out}. [The output routines were quite different
+	at this time, because output went directly to the XGP.] @622
+I87. Change the message `|completed page|' to `|Completed for page|'. @638
+B88\>48. Fix yet another typo in the computation of \\{page_total}: My original
+	code said $\\{stretch}(p)$ instead of $\\{stretch}(q)$ (terrible). @1004
+P89. Document the dirty trick about \\{bot_mark}'s reference count.
+	[That trick is, fortunately, no longer useful.] @1016
+A90. Rethink the algorithm for contributing an insertion: The original code
+	tests for a page break after incrementing the totals but
+	before the \\{contrib_list} is updated. [\TeX78 handles insertions
+	in a hardwired manner that will be greatly generalized in \TeX82.]
+F91. Fix \\{get_node} again:
+	After the variable memory overflows, control falls through to \\{found}
+	instead of going to the \\{overflow} call. @125
+# I spent several hours tracking down that data structure bug!
+B92. Change \\{new_line} to \\{next_line} in yet another print command (see \#7).
+A93\>75. Amend the line-breaking algorithm:
+	|\break| in paragraph doesn't work with really bad breaks. @851
+# A problem to be diagnosed tomorrow: Each time I run the test program,
+	the amount of memory in use grows by 13 cells not returned.
+# Seven hours tonight.
+* 17 Mar 1978
+G94. Introduce \\{dead_cycles} to keep |\end| active until \\{ship_out}
+	occurs. @1054
+E95. Don't call \\{line_break} with an empty list. @1096
+S96. Take proper account of the (infinite) fillglue when computing
+	the width of a paragraph line preceding a display. @1146
+M97. Add a new parameter to \\{hpack} so that \\{line_break} won't be called
+	at the wrong time.
+	[This is for the soon-to-be-obsolete feature described in \#40.]
+L98. Give a warning message if there's an |\hfill| in the middle of a paragraph;
+	fillglue upsets the line breaker,
+	because floating-point calculations don't have sufficient accuracy. @868
+# I spent an hour looking for another bug in \TeX, but the following one was in \MF:
+	The \\{xgp_height} data in fonts had been supplied wrong.
+# It took two hours to recompile 32 fonts with proto-\MF.
+R99. Make \\{show_node_list} and \\{show_token_list}
+	more robust in the presence of software bugs. @182
+D100\>97. Do not remove nodes with \\{eject_penalty},
+	when the new parameter to \\{hpack} is \\{true}.
+E101\>97. Put a fast exit into \\{hpack}; e.g., at glue nodes, test `{\bf if}
+	\\{paragraphing} $\land$ $\langle$current width is large$\rangle$'.
+# 2am. I have to go to bed ``early'' tonight.
+* 18 Mar 1978
+# 3:30pm. (Saturday)
+I102. Add a parameter to \\{check_mem} (to suppress display unless needed). @167
+G103. Introduce a user-settable parameter |\maxdepth|, and
+	pass it as a parameter to \\{vpackage}. @668
+# I realized the need for |\maxdepth| while fixing insertions (see \#90).
+G104. Introduce a user-settable parameter for \\{line_break}: The constant
+	2.0 in my original algorithm becomes |\jpar|
+	[later |\tolerance|], to be set like |\tracing|. @828
+D105. Reclaim the \\{eject_penalty} nodes removed during line-breaking. @879
+# (Those were the 13 extra nodes reported on Thursday.)
+# The \\{init_align} procedure worked right the first time!
+# Also \\{init_row}, \\{init_col}. But then\thinspace\dots
+S106. Rethink the command codes: \\{endv} in a token list has too high a
+	code for the assumptions of \\{get_next}. @207
+A107. Add a \\{prev_cmd} variable for processing delimited macro parameters;
+	the original algorithm loses track of braces.
+	[The rules will change slightly in \TeX82, and
+	\\{rbrace_ptr} will take on a similar function.] @400
+S108. Make the \\{get_next} routine intercept |&| and |\cr| tokens. @342
+# I'd thought I could just put |&| and |\cr| into
+	\\{big_switch} [i.e., in the stomach of \TeX, not the eyes];
+	that was a great big mistake.
+R109. Make more error checks on \\{endv}; e.g., it must not occur in
+	a macro definition or call. @780
+S110\>108. No, rethink alignments again; the new program still fails! @768
+# For the first time I can glimpse the
+	hairiness of alignment in general (e.g., `|\halign{\u#\v&...|'
+	when |\u| and |\v| are defined to include |&|'s and possible
+	alignments themselves).
+# I think there's a ``simple'' solution, by considering only whether
+	an alignment is currently active [in \S342].
+# 11:30pm. Went to bed.
+* 19 Mar 1978
+# Woke up with ``better'' idea on how to handle |&| and |\cr|.
+# (Namely, to consider a special kind of\/ |\def| whose parameters don't interrupt
+	on |&|'s and |\cr|'s.)
+# But replaced this by a much better idea (to introduce \\{align_state}).
+# 11pm. Began to use computer. Performed major surgery
+	(inserting \\{align_state} and updating the associated routines
+	and documentation).
+D111. Pop the alignment stacks in \\{fin_align}. @800
+T112\>110. Fix a (newly inserted) typo in \\{show_context}. @314
+D113\>110. Set \\{align_state} false when a live |&| or |\cr| is found.
+	[Originally \\{align_state} was of type \\{boolean}.] @789
+I114. Insert |\cr| when `|}|' occurs prematurely in an alignment. @1132
+M115. Remember to record \\{glue_stretch} when packaging an unset node. @796
+# I had a mistake in |acphdr| definition of\/ |\quoteformat|; also extra spaces.
+# My first test programs, used before today, were contrived to test macro
+	expansion, line-breaking, and page layout.
+# Next I'm using a test program based on Volume 2.
+C116. Make carriage-return, space, and tab equivalent for macro matching. @348
+F117. Omit the reference count node when displaying a mark. @176
+B118. Correct a silly slip: I wrote `\\{type_displacement}' instead of
+	`\\{value_displacement}' when packing data in a penalty node. @158
+M119. Don't go to \\{build_page} after seeing |\noindent|; \TeX\ isn't
+	ready for that.
+	[In the original program, this was an instance of a bad {\bf goto}.] @1091
+# I had undesired spaces coming thru the scanner in my macro definitions
+	of\/ |\tenpoint| [see {\sl The \TeX book}, page 414].
+# 4am. \TeX\ now knows enough to typeset page 1 of Volume 2!
+# Also it did its first ``math formula'' (namely `|$X$|') without crucial error.
+# (Except that the italic correction was missing for some reason.)
+D120. Remember to decrement \\{cur_level} in \\{fin_align}. [The routines will
+	eventually become more general and use \\{unsave} here.] @800
+D121. Remember to increment \\{cur_level} in error corrections by
+	\\{handle_right_brace}. [A better procedure will be adopted later.] @1069
+T122. Fix a typo: (`|{|' instead of `|}|') in error message for $\\{mmode}+
+	\\{math_shift}$. @1065
+R123\>99. Make \\{show_noad_list} more robust and more like the new
+	\\{show_node_list}. [The routines will be combined in \TeX82.] @690
+L124. Fix a typo in \\{char_box}: should say \\{font_info_real}.
+	[In \TeX78 a single array
+	is used for both \\{real} and \\{integer}; in \TeX82 things will be
+	\\{scaled}.] @554
+B125. Fix typos in the definitions of \\{default_rule_thickness} and
+	\\{big_op_spacing}; they shouldn't start at \\{mathex}(7). @701
+B126. Reverse the \\{before} and \\{after} conventions in math nodes. @1196
+# I had them backwards; this turned
+	hyphenation on just before math, and off just after it!
+# Seven and a half hours debugging today.
+	Got through the test program a little more.
+	But \TeX\ blew up on `|$Y+1$|'; tomorrow I hope to find out why.
+* 20 Mar 1978
+# 8pm. I decided to work next on a super-hairy formula.
+C127. Change `|\ascii|' to `|\cc|' (character code). [This name will change again
+	later, to `|\char|'.] @265
+E128. Don't bother to store a penalty node at the beginning of |$$| when
+	the paragraph-so-far fits on a single line, since such a penalty
+	has already been stored. [These conventions will change later, and
+	the |\predisplaypenalty| will always be stored.] @1203
+S129. Avoid reference to \\{tail} in \\{build_page},
+	if $\\{nest_ptr}>0$. @995
+B130. Correct a silly
+	slip in \\{math_comp} (the exact opposite of what I did in \#118). @1158
+B131. Rectify my mental lapse in \\{make_fraction}; I said \\{nucleus} instead of
+	\\{thickness}. @743
+F132. Mask off the math class when scanning delimiters. @1160
+C133. Allow an optional space after |\def{...}|. [This decision
+	will be retracted later.] @473
+# My test example is so complicated it causes the semantic stacks to overflow!
+L134. Don't test for no pages output by looking at the channel status. @642
+T135. Fix typo in definition of\/ |\mathop| (\\{open_noad} not \\{op_noad}). @1156
+A136. Rewrite \\{fin_mlist}, because `|\left(...\above...\right)|' doesn't
+	parse correctly; the |\left| goes into the numerator,
+	the |\right| into the denominator. @1184
+B137. Correct the use of \\{depth_threshold} in \\{print_subsidiary_data}:
+	Simple fields get shown while others look empty. @692
+I138\>78. Return the carriage before showing the first line of a new file
+	when pausing. @538
+M139. Fix bug: The call \\{show_noad_list}(\\{mem}[|..|]) should be
+	\\{show_noad_list}(|..|), in the \\{incompleat_noad} case
+	of \\{show_activities}. @219
+# 3am. The whole messy formula has been parsed correctly into a tree.
+# The easy part is done, now comes the harder part.
+F140. Don't shift single characters down in \\{make_op}. @749
+D141. Make \\{clean_box} return a box (as its name implies), not an hlist. @720
+# Font info still isn't quite right, it has the wrong value of \\{quad}.
+A142. Retain the italic correction when doing \\{rebox};
+	can make $\\{glue_set}\ne0$ a flag for this. [A better
+	solution will be adopted later.] @715
+B143. Fix the bug that makes \\{rebox} bomb out: $\\{value}(p)$ should be
+	$\\{value}(\\{mem}[p])$. @715
+# 6am; ten hours today. \TeX\ didn't do |$\pi\over2$| correctly, but was close.
+# I found that the \\{rebox} problem (\#142) went away when I fixed the
+	\\{clean_box} problem (\#141); but I
+	will leave the extra stuff about $\\{glue_set} \ne 0$
+	in the program anyway, just for weird cases.
+E144. Omit extra levels of boxing when possible in \\{clean_box}. @721
+# (To do this, I need to face the \\{rebox} problem anyway.)
+* 21 Mar 1978
+# 10pm. The computer is rather heavily loaded tonight.
+F145. Don't forget \\{thickness} when making a square-root sign (see \#131).
+	[The rule thickness will later be derived from the character height.] @737
+L146. Define $p$ local to the \\{make_fraction} routine. @743
+# Unwittingly using the global $p$ was a disaster.
+I147. Don't show the amount of \\{glue_set} when it's zero. @186
+D148\>142. Make \\{glue_set} nonzero in the result of \\{var_delimiter}. @706
+F149. Fix bug: The \\{math_glue} function didn't return any result. @716
+T150. Fix typo in \\{char_box} ($c$ not $w$); this caused a subscripted~$P$ to come
+	out the same width as an unsubscripted~$P$. [Later changes in the rules
+	will move this computation to \S755.] @709
+P151\>144. Revise \\{clean_box} to do operations that are needed
+	often because of the \\{rebox} change. @720
+D152. Use the new \\{clean_box} to avoid a bug in |\sqrt{\raise...}|. @737
+Q153. Change the definition of\/ |\not| so that it's a relation
+	(which will butt against the following relation). [All math
+	symbols and Greek letters are defined in |INITEX| at this
+	time, not in a changeable format definition.]
+I154. Give error message `{\tt Large delimiter must be
+	in mathex font}', instead of calling \\{confusion},
+	since the error can occur.
+	[This particular error is impossible in \TeX82.] @706
+F155. Change the use of $p$ in \\{var_delimiter}; it isn't always set when I say
+	{\bf goto} \\{found}. @706
+# Another font problem now surfaced: The mathex meta-font didn't compute \TeX\ info
+	in a machine-independent way.
+	(It took two hours to correct this.)
+D156. Don't forget to set $\\{type}(b)$ in all relevant cases of
+	\\{var_delimiter}. @708
+B157. Use the correct sign convention for \\{shift_amount} in \\{hpackage}. @653
+F158. Always kern by \\{delta} when there's no superscript. @755
+M159. Declare \\{space_table} to be $[0\,.\,.\,6,0\,.\,.\,6]$
+	not $[0\,.\,.\,7,0\,.\,.\,7]$; otherwise its entries are
+	pre\-loaded into the wrong positions. [The \\{space_table} in \TeX78 is
+	$7\times7$; it will become $8\times8$ in \TeX82,
+	represented as a string called \\{math_spacing}.] @764
+C160. Use a negative value, not zero, to represent a null delimiter.
+	[Actually zero will come back again later.] @685
+C161\>127. Change |\cc| to |\char|. @265
+L162. Don't use tricky subtraction on packed data when changing $q$ to
+	an \\{ord_noad} in \\{mlist_to_hlist}; subtraction isn't always safe. @729
+B163. Fix two typos in the \\{space_table} (|*| for |0|). @764
+F164. Initialize \\{cur_size} everywhere (I forgot it in two places). @703
+A165. Reset \\{op_noad} before resetting \\{bin_noad}. @728
+F166. Treat $\\{display_style}+\\{cramped}$ the same as \\{display_style}
+	inside \\{make_op}. @749
+B167. Shift the character correctly in the non-|\displaystyle| case of
+	\\{make_op}. @749
+# Still another font problem: The italic corrections are wrong because
+	the corresponding array was declared \\{real} in proto-\MF\ (and
+	italic corrections were used in nonstandard way in |mathex|).
+B168. Use \\{depth} instead of \\{height} in \\{var_delimiter}.
+	[Later, both were used.] @714
+Q169. Skew the accents according to the font \\{slant}. [Soon retracted.] @741
+# At this point I think nearly all the math routines have been exercised.
+# Tomorrow they should work!
+# Eight hours debugging today.
+* 22 Mar 1978
+# (Wednesday, but actually Thursday:
+	I began at midnight because I was proofreading a paper.)
+# I checked out the font access tables, slowly (i.e., all the |\mathcode|
+	and special-character name entries were catalogued).
+Q170\>169. Do {\bf not\/} consider slants after all in the math accent
+	routine, since slanted math letters are put differently into fonts. @741
+B171. Don't use $q$ for two different things simultaneously
+	in \\{make_math_accent}. @738
+F172. Fix bug in \\{compact_list} (I forgot to advance the loop variable).
+	[This procedure became unnecessary in \TeX82.]
+M173. Avoid conflict between \\{var_delimiter} and \\{mlist_to_hlist}, which
+	want to use \\{temp_head} simultaneously. @713
+T174. Fix bad typo in \\{overbar} routine ($b$ for $p$). @705
+# Finally \TeX\ got to \\{after_math} after dealing with that
+	hairy formula\thinspace\dots
+T175. Fix another bad typo: $p$ for $b$ this time. @1199
+L176. Insert more parentheses (twice) because of `|lsh|' precedence
+	in |SAIL|. @1199
+M177\>36. Use the new hanging-indentation conventions when formatting displayed
+	equations. @1199
+Q178. Recompute penalties so that break is allowed after \\{punct_noad}s. @761
+F179. Center the large delimiters vertically. @749
+Q180. Round all rule sizes (up) before drawing them. @589
+Q181. Provide more space over $x$ in $\sqrt x$, and more space atop vincula.
+	@705,737
+Q182. Make large delimiters large enough to cover formula height
+	(important for subscripts, superscripts). @762
+I183. Insert |/ntn=33| on XGP prompt message so that complex math
+	won't blow the device driver. [See \#84.]
+P184\>161. Update the comment about the meaning of\/ |\char|, since it
+	can be used in math mode. @208
+# Six hours today.
+* 23 Mar 1978
+# 11pm, Maundy Thursday.
+C185\>104. Make |\tracing| and |\jpar| follow block structure. @283
+# It took me two hours to enter yesterday's corrections,
+	because the changes were so numerous.
+M186. Fix bad call on \\{begin_token_list} when marks are to be scanned. @396
+# Now the formula looks like it should, modulo problems in fonts.
+Q187. Prevent an exponent from going below baseline + xheight/4. @758
+B188. Change \\{quad} to \\{math_quad} when finishing a display
+	(several places). @1199
+A189. Don't use \\{append_to_vlist} when putting an |\eqno| box on a separate
+	line, because the page shouldn't break at glue there.
+	[Later, the \\{append} will be used but preceded by an
+	infinite penalty.] @1205
+S190. Increase the input \\{stack_size}; \TeX\ may need to back up a lot. @11
+A191. Don't assume that $p$ always points to a glue node when
+	a page is broken. @1017
+A192. Use \\{epsilon} in \\{scan_spec} (I had used a different
+	small constant). [This was a kludge to avoid the extra
+	parameter later called \\{exactly} or \\{additional}.] @645
+R193. Introduce a new procedure \\{scan_positive_length}, to prevent
+	negative or zero lengths in \\{scan_rule_spec}.
+	[This restrictive rule will be ``overruled'' later.] @463
+B194. Fix ridiculous bug in the leaders routine of \\{vlist_out}:
+	I had the initialization {\sl inside\/} the loop! @635
+L195. Eliminate confusion between the two temp variables named $h$;
+	one is \\{real} and the other is \\{integer}. @629
+F196. Include forgotten case (\\{leader_node}) in \\{hlist_out}.
+	[Type \\{leader_node} will be absorbed
+	into \\{glue_node} in \TeX82.] @622
+F197. Don't forget to compute \\{x0} in variable horizontal rules. @624
+# Seven and a half hours today.
+# \TeX\ seems to be ready to tackle my test file based on Volume 2.
+S198. Calculate \\{y00} in horizontal rules as an integer number of pixels
+	from the baseline, so that the baseline doesn't jump. @589
+* 25 Mar 1978
+# 2am Saturday. (Might as well drop Friday.)
+D199\>185. Make \\{def_code} consistent with the new |\tracing| conventions.
+	[Many tracing options are packed into a single
+	parameter called |\tracing|.] @1233
+R200\>185. Don't allow users to change nonexistent things like |\catcode1000|. @1232
+F201\>110. Reset \\{align_state} at beginning of \\{init_align}. @774
+F202. Don't forget \\{scan_left_brace} after |\noalign|. @785
+F203\>110. Set $\\{cur_cs}\gets 0$ in \\{get_next}, after |\cr|
+	causes a switch to the $\langle v_j\rangle$ template. @342
+# Ouch, that was a big bad bug, which took me three hours to find
+	(since I thought \TeX's low-level scanning mechanism was working).
+# Note to myself: I\/ {\bf knew\/} it would be cleaner to define \\{get_next}
+	so that it sets \\{cur_cs} to zero every time it begins [i.e.,
+	in \S341, where this change will in fact be made in \TeX82].
+	But I had avoided this on grounds of efficiency in the inner loop.
+	Well, now I have earned this tiny bit of efficiency.
+D204. Prohibit the first word of an unavailable node from becoming negative.
+	[The storage allocator of \TeX78 uses
+	a negative value to signify a node that is available, just as
+	`$\\{link}=\\{max_halfword}$' will signal availability in \TeX82.] @124
+# That was another bad one, it's not my night.
+# At least I'm developing more subtle diagnostic techniques.
+M205. Remember to un-negate the top \\{save_stack} entry
+	when \\{handle_right_brace} finishes an \\{insert_group}.
+	[This routine was completely revised in \TeX82.] @1100
+F206\>185. Initialize |\jpar| [i.e., |\tolerance|]. @240
+B207. Correct the display of insertion nodes by \\{show_node_list}. @188
+R208. Prevent \\{show_token_list} from generating really long strings
+	when in a loop. @292
+D209. Increase the reference count of \\{bot_mark} when
+	\\{vpackage} finds it. [This was later the job of \\{fire_up}.] @1016
+M210. Remember that the tokenlist for a mark ends with a |}|. @1101
+D211. Don't let \\{vpackage} lose the top insert. (It fails when
+	the very first item is a |\topinsert|.) @1014
+A212. And when that stupid code is corrected, make it handle
+	insertions first-in-first-out. @1018
+# Seven hours today.
+* 26 Mar 1978
+# Easter Sunday, will work till sunrise.
+I213. Add an `|i|' feature to the \\{error} recovery routine. @87
+I214. Include a prompt. @87
+C215. Ignore space after |\noalign{...}|. @1133
+# Otherwise, things are going well tonight;
+	I'm finding more bugs in my test program than in \TeX.
+# The `|i|' feature is proving to be very helpful.
+# I increased the size of \\{mem}
+	(now $\\{lo_mem_max}=3500$, $\\{mem_max}=10000$).
+# In fact I just needed to increase it again
+	(now $\\{lo_mem_max}=4500$, $\\{mem_max}=11000$).
+R216. Make |INITEX| output \\{mem_top} for consistency checking. @1307
+A217. Calculate the size of delimiters by considering the enclosed formula's
+	distance from the axis, not from the baseline. @762
+# I'm having trouble with a |SAIL| compiler bug; I must rearrange the program,
+	more or less at random, until it
+	compiles correctly. I hope the bug isn't more severe than it appears.
+D218\>210. Don't put a new group on \\{save_stack} if a null mark is expanded.
+	[\TeX82 will remove the `|}|' from the mark text.] @386
+# I had to redo the typewriter-style font since its width tables were wrong.
+# And I increased low-memory size again to 5500, then 6500.
+# Finally the entire test program was \TeX ed. Happy Easter! Six hours today.
+* 27 Mar 1978
+# Beginning at 2:30am.
+A219. Move |\vcenter| processing to the first pass of \\{mlist_to_hlist};
+	otherwise the height, depth, subscripts, etc., are way off. @733
+C220. Omit space after closing |$$|. @1200
+# Spacing is wrong in the formula $Y_1+\cdots+Y_k$; I have to rethink the use
+	of three dots.
+G221. Make conditional thin space available to user as |\|{\tentex\char'34}.
+	[Later will retract this.] @226
+Q222. Introduce |\dispaskip| and |\dispbskip| [later called
+	|\abovedisplayshortskip| and |\belowdisplayshortskip|]. @226
+# Reminder: I need to test line-breaking with embedded math formulas.
+I223. Make sure that $\\{interaction}\ne\\{error_stop_mode}$
+	in the `|Whoa|' error [\\{fatal_error}]. @93
+B224. Fix a big mistake in the \\{style_node} routine (which points to a glue spec,
+	not to glue itself); somehow this didn't cause trouble yesterday.
+	[In \TeX78, style nodes double as placeholders for math glue
+	like thin spaces.] @732
+C225. Make |\fntfam| obey group structure. [\TeX78's |\fntfam| operation
+	is a combination of \TeX82's
+	|\textfont|, |\scriptfont|, and |\scriptscriptfont|.] @1234
+# At this point the test routine for Volume 2 works perfectly.
+# But I will change the page width in order to check harder cases.
+Q226\>178. Disable automatic line breaks after punctuation in math
+	(e.g., consider $f(x,y)$). @761
+S227. Represent italic corrections as boxes, not glue, so that they won't be broken.
+	[The |\kern| command doesn't exist yet.] @1113
+# Eight hours today.
+B228. Fix a bug that just clobbered the memory: Call \\{free_avail}, not
+	\\{free_node}, in the \\{ins_node} case of \\{vpackage}.
+	[This logic will change completely in \TeX82.] @1019
+* 29 Mar 1978
+# (Wednesday) Again beginning at 2:30am.
+Q229. Put still more space above and below fraction lines in displayed
+	formulas. @746
+G230\>189. Install an infinite penalty feature, which positively suppresses breaks;
+	use it in displayed formulas whose |\eqno| doesn't fit. @1205
+F231. Call \\{build_page} after finishing a display; and don't
+	go to the |\noindent| routine because of the next remark. @1200
+S232. Put |\parskip| glue just before a paragraph, not just after
+	(since it interferes with a penalty after). @1091
+# Although the test program gives correct output, it generates 46 locations
+	of variable-size memory and 280 of one-word memory that are not freed.
+F233. Recycle the ulists and vlists in \\{fin_align}. @801
+M234\>25. Fix bug when deleting space at end of paragraph:
+	\\{delete_glue_ref}(\\{cur_node}) not
+	\\{delete_glue_ref}(\\{value}(\\{cur_node})). @816
+# There's also a more mysterious type of uncollected garbage,
+	a \\{fraction_noad} corresponding to
+	|$p\choose$|, an \\{incompleat_noad} not completed.
+# Couldn't find that one, so I recompiled with \#233 and \#234 corrected.
+# Now it gains just 10 locations of variable-size memory and 7 of the other kind.
+I235. Extend \\{search_mem} to search \\{eqtb} also. @255
+D236\>143. Fix bug in \\{rebox} when $\\{list_ptr}(b)=0$. @715
+# The seven one-word nodes were generated by this bug;
+	\\{rebox}\kern-1pt\ put them onto a linked list starting with
+	$\\{mem}[0]$, growing at the far end!
+D237. Remember to complete each \\{incompleat_noad}. @1184
+# This solved the other mystery. I had never noticed that my test output
+	was actually wrong: |$p\choose k$| came out as `$k$'.
+# After these corrections, the test routine worked\thinspace\dots\ I feel
+	that \TeX\ is now pretty well debugged
+	(except perhaps for error recovery)---it's time to celebrate!
+* 1 Apr 1978
+I238. Don't quit after file lookup fails. @530
+* 2 Apr 1978
+P239. Add \\{\TeX_font_area}, so that it's easier to change the
+	default library area associated with a device. @514
+* 3 Apr 1978
+L240. Insert parentheses again, to cope with the precedence of\/ |lsh|
+	when packing data. (See \#55 and \#176.) @1114
+# I had never tried $\\{hmode}+\\{discretionary}$ before!
+M241. Remember that \\{back_error} requires \\{cur_tok} to be set.
+	(Problem can arise during error recovery on parameter |#|$n$
+	with $n$ out of range.) @476
+* 4 Apr 1978
+I242. Add a deletion feature to the \\{error} routine. @88
+* 5 Apr 1978
+Q243. Reset \\{space_factor} after |\/| [this was later rescinded]
+	and after math in text. @1196
+* 10 Apr 1978
+G244\>104. Replace |\jpar| and |\tracing| by a new primitive |\chpar| for parameters.
+	It allows a user to change those quantities as well as the penalties for
+	hyphens, relations, binary ops, widows. @209
+* 14 May 1978
+# Beginning to typeset a real book (Volume 2, second edition), not just a test.
+Q245. Make math in text end with spacing as if it were
+	followed by punctuation. [This rule will soon be rescinded.] @760
+F246. Insert |\times| into the hash table; I left it out by mistake.
+	[It will eventually move into |plain.tex|.]
+C247. Change the names of Scandinavian accents from |\o|, |\oslash|,
+	|\Oslash| to |\a|, |\o|, |\O|. [This will also move to |plain|.]
+* 17 May 1978
+B248. Fix a silly bug that hasn't been tweaked until today:
+	`|\halign to size|' [obsolete in \TeX82] used \\{vsize}
+	instead of \\{hsize}. @645
+* 19 May 1978
+G249. Add a |\topbaseline| feature [later called |\topskip|]. @1001
+Q250\>245. Subtract the math spacing change of May 14. @760
+A251. Skip past blanks in the \\{scan_math} procedure. [This blank-skipping
+	will eventually go into \\{scan_left_brace}.] @403
+I252. Introduce a \\{missing_brace} routine [later generalized] to improve
+	error recovery in $\\{mmode}+\\{math_shift}$, when the top
+	of \\{save_stack} isn't a \\{math_shift_group}. @1065
+Q253. Adjust the math spacing between closing parentheses and
+	Ord, Op, Open, Punct. @764
+Q254. Make the underline go further under. @735
+S255\>96. Compute the proper natural width when a displayed equation follows
+	a paragraph whose fillglue has been deleted by \\{line_break}. @1146
+* 20 May 1978
+A256. Fix the spurious value of \\{prev_depth} inside alignments. @775
+S257. Consider (and defeat) the following scenario:
+	The u and v lists are built in \\{init_align} using \\{temp_head};
+	then while scanning `|\tabskip 2pt\rt{...}|' the macro |\rt| is expanded,
+	clobbering \\{temp_head}. @779
+# That bug was more subtle than usual.
+Q258. Add the parameter \\{num3}, so that the positioning of\/ |\atop|
+	can be different from that for fractions. @700
+Q259. Add new parameters \\{delim1} and \\{delim2}, so that
+	|\comb| can use fixed size delimiters, not computed as with |\left|. @748
+* 22 May 1978
+C260\>221. Change |\|{\tentex\char'34} to |\|{\tentex\char'35} and introduce
+	|\|{\tentex\char'34} as the negative of\/ |\|{\tentex\char'35}.
+	[Later obsolete.] @226
+L261. Fix the display of negative penalty nodes; \\{show_node_list} is confused
+	when a negative value has been packed into the middle of a word. @194
+# Memory overflow just occurred with $\\{lo_mem_max}=7500$ and $\\{mem_max}=16384$.
+	So I have to go to 15-bit pointers. (A problem on 32-bit machines?)
+* 23 May 1978
+Q262. Add a new parameter \\{big_op_spacing5}, for
+	extra space above and below limits of big displayed operators. @751
+F263. Initialize \\{incompleat_noad} in |$$\halign{...}$$|. @775
+# That was another heretofore-untested operation. How much of the code
+	has not yet been exercised?
+F264\>238. Close the file when doing lookup-failure recovery. @27
+I265. Improve the error recovery for `|Extra &|'. @792
+R266. The top piece must be calculated mod 128 in \\{var_delimiter},
+	to guarantee a valid subscript range. [Obsolete in \TeX82.] @546
+B267\>252. Fix a blunder in new \\{missing_brace} code. @1065
+B268\>262. Fix a blunder in new code for limits on display operators. @751
+* 26 May 1978
+Q269. Don't insert a new penalty after an explicit penalty in math mode. @767
+# The hash table overflowed; I ought to make it much bigger.
+R270\>110. Avoid possible bad memory references in alignment
+	when there is erroneous input after |\cr|. [Instead of
+	\\{extra_info}, the value of \\{cur_align} in \TeX78 is negated,
+	because we need only distinguish |\cr| from |&|.] @789
+S271. Make the dimension parameters like |\hsize| all global, so that they can
+	be set in the |\output| routine. @279
+# This led to major simplifications, also to major surgery.
+# [But it was a kludgy decision, overruled in \TeX82.]
+D272\>94. Don't forget to set the type of the new null box in the |\end| routine. @1054
+* 27 May 1978
+# The data overflowed memory again, both low and high, doing Section 3.3.2.
+R273\>184. Mask off extra bits of\/ |\char| in math mode,
+	to avoid bad memory references. @1151
+B274. Zero out the negative |\medmuskip| in script styles. @732
+* 29 May 1978
+S275. Be prepared to handle an undefined control sequence during \\{get_x_token}.
+	(Can fix this by brute force, using \\{get_token} instead of \\{get_next}.)
+	@380
+D276. Correct the superscript shift when a single character is raised. @758
+R277\>184. Mask off all but 7 bits in |\char| routine,
+	to avoid space-factor index out of range. @435
+# More memory capacity overflows.
+E278\>22. Fix \TeX's overflow stop so that I don't have to wait for loading of the
+	|BAIL| debug routines. [System dependent.] @93
+F279. Remember to adjust the page number
+	when a file page ends in mid-macro. [System dependent.] @306
+* 5 Jun 1978
+R280. Make sure that the arguments of positioning commands don't overflow
+	their field size. @610
+I281. Report the excess amount when giving an overfull box warning. @666,677
+* 7 Jun 1978
+Q282. Use $\ge$ instead of $>$ as termination criterion in \\{var_delimiter}. @714
+R283. Disallow |\eject| in math mode. [In \TeX78, |\eject| is
+	distinct from |\break|; in horizontal mode it includes
+	\TeX82's `|\vadjust{\break}|'.] @1102
+Q284. Don't put too much clearance above |\sqrt| in text style. @737
+* 9 Jun 1978
+G285\>110. Make \\{align_state} an integer variable, not \\{boolean},
+	so that |\eqalign| can be within another |\eqalign|. @309
+C286. A |\mark| should expand its input. @1101
+* 10 Jun 1978
+E287. Provide for preloading of fonts. @1320
+L288. Close the output file before switching to edit the input file with
+	the `|e|' option. @84
+E289. Return adjustments found by \\{hpack} to free storage if
+	they're not used. [Later, \\{hpack} will detach them only
+	when they're used.] @655
+Q290. Strive for consistency between \\{make_under} and \\{make_over}.
+	@735
+* 18 Jun 1978
+B291\>236. Fix a serious error in \\{rebox}
+	(`$b$' instead of `$\\{list_ptr}(b)$'). @715
+# Strange that such a bug would now surface for the first time!
+C292. Remove |\deg| from |INITEX|, since macros suffice.
+Q293. Add an extra hyphenation penalty for two hyphenated lines in a row. @859
+* 19 Jun 1978
+S294. Introduce the `\\{no_new_control_sequence}' switch. Among other things,
+	this will prevent an undefined control sequence following \\{scan_math}
+	from clobbering the save stack. @259
+* 20 Jun 1978
+L295. Change the badness test
+	`$\\{glue}\le0.0$' to `$\\{glue}\le0.0001$'. [\TeX82 will avoid such
+	problems by calculating badness without floating point arithmetic.] @99
+R296. Force \\{badness} to be at most $10^{19}$. @108
+I297. Add \\{end_template} for better error recovery in alignments. @375
+E298\>287. Make |INITEX| more like the real \TeX; my simple scheme for
+	font preloading was no good because it left thousands of `dead'
+	words in memory. @8
+E299. Economize disk space by using internal arrays in load
+	modules that aren't being reinitialized. [System dependent.]
+E300. Move the declaration of \\{mem} to the semantics module, so that the
+	object code will be more efficient. [System dependent. The code of
+	\TeX78 was divided into separately compiled modules for syntax,
+	semantics, output, extensions, and general organization.]
+* 21 Jun 1978
+# Today I'm working on the user manual.
+C301. Disallow |\input| except in vertical mode. [I will change this in
+	\TeX82, treating |\input| as a case of expansion.] @378
+I302. Add error recovery for \\{endv} and \\{par_end} occurring in math mode.
+	@1047
+G303. Generalize |\ifT| to |\if T|. @506
+* 22 Jun 1978
+F304. Preload the |\bullet| [later done by |plain.tex|].
+D305\>256. Get the correct \\{prev_depth} at the beginning of an alignment. @775
+C306. Change |\eject| so that it ejects only once. @1000
+* 14 Jul 1978
+I307. Look in standard area if a file isn't found in the user's area. @537
+I308. Echo all online inputs in the transcript file. @71
+* 19 Jul 1978
+Q309. Equalize spacing when only one of numerator/denominator is big. @745
+Q310. Prevent subscript from getting too high above baseline. @757
+R311. Avoid infinite loop when stack overflows: \\{push_input} should say
+	`{\bf if} $\\{input_ptr}\ge\\{stack_size}\;\land\;\\{interaction}=
+	\\{error_stop_mode}$'. @321
+* 22 Jul 1978
+C312. Make |\quad| meaningful outside math mode. (All fonts must
+	be generated again!) @558
+I313. Show the nesting level at the end of \\{show_activities}.
+	[But I decided not to do this in \TeX82.] @218
+C314. Put in |\>| [namely, |\mskip\medmuskip|;
+	\TeX78 already has |\|{\tentex\char'35}, for conditional |\thinmuskip|,
+	as well as the negative amounts |\<|,~|\|{\tentex\char'34}].
+	Change the name of vector accent from |\>| to |\b|. [Math spacing
+	operators will become much more general in \TeX82.] @716
+* 25 Jul 1978
+Q315\>94. Give the correct |\hsize| and |\vsize| to the null boxes created
+	at |\end|. @1054
+A316\>94. And don't ``append'' them. [Later this was changed, so
+	that it would work better with generalized output routines.] @1054
+I317\>297. Remove the control sequence |\endv|,
+	since error recovery is now better. @375
+I318. Define another mode of tracing: It says `|OK|' and stops after
+	|\showlists|. @1298
+Q319\>244. Give better defaults to parameters. [Later done by |plain.tex|.] @209
+I320. Allow more bits in the packed representation of\/ |\showboxdepth|. @238
+I321. Scan past delimiters and/or dimensions when recovering from
+	ambiguous fractions. @1183
+R322. Reduce accent numbers modulo 128 or 512, depending on the
+	mode. @1165
+I323. Include a warning, `|(\end occurred on level ...)|'. @1335
+* 28 Jul 1978
+# (I'm writing Chapter 27 of the manual: `Recovery From Errors'.)
+I324. Improve the error message in \\{scan_digit}. [This procedure will change
+	its name to \\{scan_eight_bit_int}, when the number of registers
+	increases from 10 to~256.] @433
+I325. Don't report overfull boxes if they're less than .1~point
+	over. @666,677
+I326. Give the user extra chances to define the font, if \\{read_font_info}
+	is unsuccessful. @560
+I327. Change default recovery for bad parameter number from |#1| to |##|, since
+	|#1| won't always work and since |##| is probably intended. @479
+I328. Omit the |"Negative?"| message on things like \\{scan_char_num}. @435
+I329. Improve error recovery when a large delimiter isn't in family~3.
+	[Obsolete.]
+I330. Give a more appropriate error message when the input is `|$\right|'. @1192
+# Currently \TeX\ says `|Missing $|'!
+I331. Call \\{back_input} before the error message in \\{back_error},
+	not afterwards. @327
+* 1 Aug 1978
+I332. Give an appropriate warning when there's no input file and the user
+	types `|e|'. @84
+L333. Increase the system pushdownlist size so that the manual will compile.
+	[Procedures \\{hlist_out} and \\{vlist_out} can recurse deeply.]
+# Yesterday I distributed 45 preliminary copies of the manual; today I
+	took out the ``debugging hooks'' and put \TeX\ up as a system program.
+* 2 Aug 1978
+# I'm typing Volume 2 again (currently in Section 4.2.2). Culture shock!
+G334. Introduce a |\ragged| parameter, to indicate a degree of raggedness.
+	[Previously, ragged-right setting was performed when the
+	|\tolerance|/100 was odd! Eventually a better approach,
+	with |\rightskip| and such things, will be discovered.] @886
+Q335. Omit the `widow penalty' in one-line paragraphs. @890
+* 5 Aug 1978
+G336. Generalize |\pageno| to |\count|\<digit>. @236
+D337\>285. Update \\{align_state} when recovering from `|Missing {|' and
+	`|Extra }|' errors. @1069,1127
+I338. Show ``runaway'' tokens, making it easier to pinpoint an error. @306
+* 22 Aug 1978
+G339. Add |\predisplaypenalty|. @1203
+I340. Clarify error messages; they should indicate when something has been
+	inserted, etc. @1064
+* 23 Aug 1978
+I341\>114. Substitute `|Extra }|' for the losing `|Missing \cr|' error message. @1069
+I342\>213. Go past online insertions in \\{show_context}. @311
+Q343. Exact no penalty for breaking one line before a display. @1145
+I344\>338. Check for runaways at end of file. @362
+I345. Give error message when a macro argument begins with |}|. @395
+* 24 Aug 1978
+L346\>213. Remove extra line-feed in \\{show_context} after printing insertions.
+	[System dependent.] @318
+* 25 Aug 1978
+Q347. Leave no glue at top of page, even after |\eject|. @997
+* 27 Aug 1978
+P348. Adopt Guy Steele's new version of the \TeX\ source files. [He has
+	recently made a copy and modified it by introducing
+	compile-time switches for MIT conventions as an alternative to SUAI.
+	This is the first time that \TeX\ is being ported to another site;
+	additional switches for PARC, TENEX, TOPS10, and TOPS20 will be
+	added later, using the Steele style.]
+* 1 Sep 1978
+Q349. Don't pass over leader nodes in the \\{try_break} background
+	computation. [At this time, leaders have not yet been
+	unified with glue.] @837
+Q350\>82. Prune away all penalties at the top of a page. @997
+* 4 Sep 1978
+I351\>338. Include `|\|' in error message about a runaway argument. @306
+* 8 Sep 1978
+# I just remade all the fonts, with increased ligature field size.
+B352\>350. Insert a necessary {\bf goto} statement in the first branch of
+	the new penalty routine within \\{build_page}. @997
+* 30 Sep 1978
+M353\>338. Make the token list for runaway arguments meaningful outside
+	of \\{macro_call}. (I just had a runaway argument ending with
+	`|\lcm|', which turned out to be the
+	control sequence in hashtable location 0.) @371
+R354. Avoid infinite loop when recovering from |$$| in
+	restricted horizontal mode. @1138
+L355. Fix two hyphenation bugs related to |-ages|, |-ers|.
+	[A completely new algorithm for hyphenation will go into \TeX82.]
+Q356. Add |-est| to hyphenation routine;
+	also disable |puz-zled| and |rat-tled|, etc.
+* 4 Oct 1978
+G357. Add new primitive |\vtop|. @1087
+Q358. Treat implicit kerns properly after discretionary hyphens have been
+	inserted. @914
+* 4 Nov 1978
+Q359. Forget the half quad originally required at left and right when
+	centering displayed equations without equation numbers. @1202
+* 11 Nov 1978
+R360. Don't let the postamble come out empty. [This could occur if no fonts were
+	selected.] @642
+* 15 Nov 1978
+C361. Allow optional space after digit in \\{scan_int} routine. @444
+* 17 Nov 1978
+R362. Make the \\{check_mem} procedure slightly more robust. @167
+* 20 Nov 1978
+C363. Make the |\par| in a |\def| match the |\par| that comes automatically with
+	a blank line. (Suggested by Terry Winograd.) @351
+G364. Add new parameter |\mathsurround| for spacing before and after
+	math in text. @1196
+G365. Extend |\advance| to allow increase by other than unity. [At this
+	time it applies only to the ten |\count| registers, and it is
+	called |\advcount|.] @1238
+* 25 Nov 1978
+G366. Add a new primitive: |\unskip|. @1105
+G367. Add new primitives |\uppercase| and |\lowercase|. @1288
+* 28 Nov 1978
+M368\>338. Don't let |\mark| and \\{macro_call} interfere with each other's
+	\\{scanner_status}. @306
+M369. Omit extra |}| after \\{show_node_list} shows a |\mark|,
+	since the right brace is already there. (See \#210.) @176
+G370. Add a new primitive suggested by Terry Winograd: |\xdef|. @1218
+* 29 Nov 1978
+S371. Delete a space following |\else{...}| also in the
+	false case. [\TeX78 uses braces, not |\fi|, for conditionals.]
+D372\>320. Make |\tracing| set |\showboxbreadth| as advertised. @198
+F373. Account properly for kerns in width calculations of \\{line_break}.
+	@866
+Q374\>364. Delete a \\{math_node} at the beginning of a line. @148
+A375\>339. Guarantee that |\predisplaypenalty=10000| will suppress page breaking
+	before a display. @1005
+* 6 Dec 1978
+L376. Change the file opening statement to allow lines up to 150 characters long.
+	[System dependent.]
+* 16 Jan 1979
+F377\>365. Initialize \\{negative} properly in the |\advance| routine
+	with a |\count| as argument. @440
+* 20 Jan 1979
+R378. Try to keep complex, buggy preambles of alignments from
+	crashing the program. @789
+* 17 Feb 1979
+I379\>376. Give more detailed information when warning about a
+	long line being broken. [System dependent;
+	the buffer size in \TeX78 is very limited.]
+L380. Declare $p$ local to \\{try_break}, for the ``rare'' case code.
+	[My original program included the following comment:
+	``This case can arise only in weird circumstances due to
+	changing line lengths, and the code may in fact never be executed.''
+	Later Michael Plass will discover that variable line lengths require an
+	entirely different algorithm, using \\{last_special_line}.]
+	@847
+F381\>334. Don't omit the raggedness correction when the
+	last line of paragraph has to shrink. [Obsolete in \TeX82.]
+* 22 Feb 1979
+F382\>363. Don't forget to return from \\{get_x_token} after finding |\par|. @351
+Q383. Add a new parameter: |\lineskiplimit|. @679
+C384. Change the syntactic sugar:
+	`|\hbox par|' replaces `|\hjust to ...{overfull}|'. [This vastly improves on
+	the old idea (see \#40), but there still is no internal vertical mode.]
+C385. Introduce new names |\hbox| and |\vbox| for |\hjust| and |\vjust|. @1071
+G386. Add a new condition: |\ifpos|. [It will later be
+	generalized to |\ifnum| and |\ifdim|.] @513
+G387. Add |vu| and |\varunit|. [\TeX82 will eventually allow arbitrary
+	internal dimensions as units of measure.] @453
+G388\>312. Add an |em| unit. @455
+C389. Legalize |\hbox spread |\<negative dimension> [since \\{scan_spec}
+	no longer uses the sign as a flag]. @645
+* 10 Mar 1979
+C390\>370. Make \\{scan_toks} expand |\count| during |\xdef|. [This will
+	change later when |\the| and |\number| are introduced.] @367
+* 23 Mar 1979
+Q391. Put only 100000\thinspace pt stretch at the end of a paragraph instead of
+	10000000000\thinspace pt.
+	[In \TeX78, ``infinite'' glue is actually finite but large; in the
+	language of \TeX82 we would say that |\parfillskip|, which is
+	not yet user-settable, is being changed to be like |\hfil| instead of
+	like |\hfill|.] @816
+Q392. Treat the last line of a paragraph more consistently with
+	the other lines (e.g., when |\hfil| appears in mid-paragraph), by
+	effectively inserting \\{inf_penalty} at the end. @816
+* 31 Mar 1979
+S393. Ensure that penalty nodes aren't wiped out, in weird cases where
+	breaks occur at penalties that normally disappear. @879
+* 27 Apr 1979
+A394. Correct the page number count when files begin with an empty page.
+	[System dependent.]
+G395. Allow the \\{math_code} table to be changeable via |\chcode|.
+	[In \TeX82, |\chcode| will split into |\mathcode| and |\catcode|.] @1232
+I396\>332. Don't accept `|e|' after an error message if not
+	inputting from a file. @84
+* 29 May 1979
+F397. Don't call \\{end_file_reading} if you haven't already invoked
+	\\{begin_file_reading}; this could happen when trying to
+	recover from an error in \\{start_input}.@537
+* 7 Jun 1979
+A398\>306. Be sure to eject two pages,
+	when |\eject| comes just at the time another break is preferable
+	(e.g., when the page has just become too full). @1005
+* 27 Jun 1979
+I399\>354. Don't say `|You can't do that in math mode|' when the user
+	says `|$$|' in restricted horizontal mode! @1138
+* 30 Jun 1979
+G400. Add |wd|, |dp|, |ht| dimension units. @455
+I401\>307. Don't try the system area for file names whose area is explicitly
+	indicated. @537
+* 1 Jul 1979
+G402. Allow letters as (ASCII) numbers [without the |`| marker introduced
+	later]. @442
+* 2 Jul 1979
+F403. Fix a |\gdef| bug: If the control sequence was never defined before
+	[this later became the \\{restore_zero} option],
+	don't remove it at group end. @282
+* 16 Jul 1979
+I404\>320. Update \\{show_noad_list} to be like \\{show_node_list}.
+	[The two routines, originally separate, will be merged in \TeX82.] @238
+* 18 Jul 1979
+G405. Extend capacity from 32 fonts to 64 fonts if desired. @134
+Q406. Add new \\{extra_space} parameter to all text fonts (requested
+	by Frances Yao). @558
+F407. Make each \\{node_noad} print properly in \\{show_noad_list}. @183
+Q408. Make |\jpar| allow any break if it is 1000000 or more.
+	[In \TeX82, a |\tolerance| of 10000 or more allows any break.] @851
+* 23 Jul 1979
+E409. Introduce new primitives |\hfil|, |\vfil|, |\hfilneg|, |\vfilneg|. @1058
+G410. Add |\ifmmode|. @501
+G411. Add |\firstmark|. @1012,1016
+C412. Allow break at leaders (horizontal mode only). @149
+* 25 Jul 1979
+I413\>213. Revise \\{error} so that online insertions work properly
+	after end-of-file errors. @336
+B414\>411. Change `{\bf if} $\\{first_mark}\ne0$' to
+	`{\bf if} $\\{first_mark}\ge0$' [because $-1$
+	is used to indicate `not yet given a value']. @1012
+* 28 Jul 1979
+C415\>370. Stop |\xdef| from expanding control sequences after |\def|'s.
+	[This decision will be rescinded later, after several more years of
+	experience with macro expansion will suggest better ways to cure
+	the problem.] @366
+I416. Change symbolic printout for control symbols. [System dependent.] @49
+L417\>308. Avoid linefeeds in the transcript file. [System dependent.]
+C418\>370. Expand |\topmark|, etc., in |\xdef|. @366
+* 4 Aug 1979
+B419\>413. Fix an error introduced recently: |\par| was suddenly
+	omitted at end of page. [System dependent.]
+* 11 Aug 1979
+P420. Change error messages that use |SAIL| characters not in
+	standard ASCII. @360
+* 28 Aug 1979
+D421\>411. Move the command `$\\{first_mark}\gets-1$' from \\{vpackage}
+	to \\{fire_up}. @1012
+S422\>403. Correct a serious |\gdef| bug:
+	Control sequences don't obey a last-in-first-out
+	discipline, so \TeX\ loses things from the hash table when deleting a
+	control sequence. @259
+# To fix this, I either need to restrict \TeX\ (so that
+	|\gdef| can be used inside a group only for control sequences already
+	defined on the outer level) or need to change the hash table algorithm.
+	Although all applications of \TeX\ known to me will agree to the
+	former restriction, I've chosen the latter alternative, because it gives me
+	a chance to improve the language: Control sequences
+	of arbitrary length will now be recognized.
+D423. Make sure that \\{unsave} cannot call \\{eq_destroy}
+	with a value from the upper part of \\{eqtb}. @282
+# I noticed this long-standing bug while fixing \#422. It had very
+	low probability of causing damage (e.g., it required a certain field
+	of a floating-point number to have a certain value), but it would have
+	been devastating on the day it first showed up!
+* 29 Aug 1979
+F424. Call \\{eq_destroy} when a control sequence is |\gdef|'ed
+	after being |\def|'ed. @283
+F425\>418. Treat the first token consistently
+	when |\topmark| and its cousins are expanded in \\{scan_toks}. @477
+# Now I've checked things pretty carefully and I think \TeX\ is ``fully debugged.''
+* 25 Jan 1980
+I426\>338. Display runaway alignment preambles. @306
+G427. Introduce active characters (one-stroke control sequences).
+	[I don't yet go
+	all the way: The meanings of `|x|' and `|\x|' have to be identical.] @344
+* 7 Feb 1980
+F428\>314. Fix a glaring omission: Op space |\>| was
+	never implemented in math mode! @716
+* 25 Feb 1980
+G429. Add a new dimension `|ex|' (for units of xheight). @455
+* 3 Mar 1980
+C430\>427. Allow the control sequence |\:| to be redefined
+	[it was the `select font' operator];
+	this allows the character |:| to be active. [Obsolete.]
+* 23 Mar 1980
+# An extend-\TeX-for-the-eighties party:
+G431. Add a new |\copy| feature. @204
+G432. Add a new |\unbox| feature. @1110
+G433. Add a new |\open| feature [later |\openout|]. @1351
+G434. Add a new |\send| feature [later |\write|]. @1352
+G435. Add a new |\leqno| feature, requested by MDS. @1204
+G436. Add a new |\ifdimen| feature [later |\ifdim|]. @513
+C437. Make |\|\<space> in vertical mode begin a paragraph. @1090
+G438. Add a new |\font| feature [replacing the silly previous convention that
+	a font must be defined when it is first selected]. @1256
+G439. Add new |\parval| and |\codeval| features [later
+	|\the|\thinspace\<whatever>\thinspace]. @413
+C440\>427. Don't let active characters gobble the following space. @344
+G441\>208. Add a new parameter to govern amount of token list dumped. [Obsolete.] @295
+G442. Add a new |\linebreak| feature [later replaced by |\break|]. @831
+* 25 Mar 1980
+# (Still working on the above, also thought of more.)
+G443. Add a new |\mskip| feature. @716
+G444. Add a new |\newname| feature (soon changed to |\let|). @1221
+G445\>430. Allow any control sequence to be redefined. @275
+I446. Send the output to the user's current file area, even when
+	input comes from elsewhere. @532
+* 27 Mar 1980
+Q447. Compute the xheight for accents in math mode from
+	family~1, not family~3. [Obsolete.]
+* 28 Mar 1980
+Q448. Increase minimum clearance between subscript and superscript. @759
+* 29 Mar 1980
+Q449\>222. When a display follows a display, the second should have the
+	`shortskip' glue. @1146
+* 4 Apr 1980
+A450\>445. Look at current token meanings when trying to recognize
+	|\tabskip| in alignment preambles. @782
+* 23 Apr 1980
+I451. Estimate the length of printed output, for the new
+	priority feature on our XGP device driver. [System dependent.]
+C452\>434. Break long |\send| lines
+	into pieces so that the file can be read in again. [System dependent.]
+* 19 May 1980
+Q453\>182. Don't make |\left| and |\right| delimiters too large; they
+	need to be only 90\% of the enclosed size. [This eventually
+	became |\delimiterfactor|.] @762
+* 21 May 1980
+G454. Add a new |\pagebreak| feature [later |\vadjust{\break}|]. @655
+* 13 Jun 1980
+# Today I'm beginning to overhaul the line-breaking routine,
+	and I'll also install miscellaneous goodies.
+G455. Allow a radical sign to be in different font positions. @737
+E456. Clear empty tokenlists off input stacks to allow deeper recursions
+	(suggested by Jim Boyce's macros for chess positions). @325
+G457. Make |\spaceskip| and |\parfillskip| changeable. @1228
+G458. Add a new parameter |\rfudge| (per request of Zippel) [later |\mag|]. @288
+G459. Add a new parameter |\loose| [later |\looseness|];
+	now parameters are allowed to take negative values. @875
+E460. Remove the variable \\{just_par}. [Obsolete; it was the \\{real} equivalent
+	of an \\{integer}].
+* 14 Jun 1980
+Q461. Install new line-breaking routines, including |\parshape|.
+	(These major changes are introduced as Michael Plass
+	and I write our article.) @813
+G462. Add a new parameter |\exhyf| [later |\exhyphenpenalty|]. @869
+* 16 Jun 1980
+S463\>444. Change conventions in \\{eqtb} so that glue is distinguishable
+	from other equivalents. @275
+A464\>444. Don't expand |\b| in |\xdef{\d\b{...}}| after |\let\d=\def|.
+	[Obsolete.]
+D465\>444. Avoid creating dead storage when doing \\{unsave} in certain regions. @275
+* 17 Jun 1980
+C466. Allow negative dimensions in rules. @138
+* 19 Jun 1980
+B467\>463. Make the new test for glue at the outer level of \\{show_eqtb}. @252
+* 27 Jun 1980
+Q468\>453. Don't let |\left| and |\right| become too small for big matrices.
+	[This eventually became |\delimitershortfall|.] @762
+* 3 Aug 1980
+Q469. Don't move extra-wide, numbered equations flush left unless
+	they begin with glue. @1202
+* 15 Sep 1980
+M470\>461. Say `$\ge\\{fz}$' instead of `$>\\{fz}$' in the pre-hyphenation
+	routine; I'd forgotten my definition of \\{fz} [a variable used to test
+	for a sequence of lowercase letters in the same font]. @897
+R471\>395. Check the range of the index in |\chcode| before saving the old value.
+	@1232
+* 18 Sep 1980
+D472\>457. Don't forget to increase the reference count to |\parfillskip|,
+	or it will mysteriously vanish. @816
+* 19 Sep 1980
+C473\>412. Make leaders break like glue in both horizontal and vertical modes.
+	@149
+Q474\>364. Make |\mathsurround| break properly at left and right end of lines.
+	@879
+* 13 Oct 1980
+I475\>461. Remove spurious overfull boxes generated when the looseness criterion
+	fails. [Obsolete.]
+A476\>461. Redesign the iteration for looseness; breakpoints were not chosen
+	optimally. @875
+E477\>461. Avoid storing a lot of breakpoints when they are dominated by
+	others. @836
+B478\>366. Don't say `\\{cur_node}' when you mean `\\{mem}[\\{cur_node}]'. @1105
+Q479\>461. Prefer the oldest break to the youngest break
+	when two break nodes have the same total demerits. @836
+L480\>461. Don't make badness too big for floating-point calculations,
+	when forced to make an overfull box. [Obsolete.]
+* 10 Dec 1980
+R481. Make it impossible to get unmatched `|}|' in a delimited macro
+	argument. @392
+G482. Add new |\topsep| and |\botsep| features. [These are \TeX78's
+	way to put space at the edge of inserts,
+	replaced in \TeX82 by the |\skip| register corresponding
+	to an |\insert| class.] @1009
+* 6 Jan 1981
+P483. Install new routines for reading the font metrics, using Ramshaw's
+	|TFM| files instead of\/ |TFX| files. @539
+I484. Abort after reporting 100 errors, if not pausing on errors. @82
+G485. Add new |\spacefactor| and |\specskip| and |\skip| primitives.
+	[At this time we write `|\specskip3=10pt|' and `|\skip3|' for what
+	will become `|\skip3=10pt|' and `|\hskip\skip3|' in \TeX82.] @1060
+G486\>366. |\unskip| is now allowed in internal vertical mode. @1105
+* 26 Jan 1981
+B487\>482. Don't say `\\{mem}[$q$]' when you mean `$q$'. (See \#143 and \#478.) @1009
+* 27 Feb 1981
+I488\>417. Put some linefeeds back into the transcript file, in order
+	to prevent overprinting in listings. [System dependent.]
+G489. Add a new |\dpenalty| feature [later |\postdisplaypenalty|]. @1205
+G490. Add the dimension |cc| for European users. @458
+C491. Make \\{scan_keyword} match uppercase letters as alternatives
+	to lowercase ones (suggested by Barbara Beeton's experiments
+	with |\uppercase|). @407
+I492. Add nonstop mode so that overnight batch processing is possible. @73
+* 2 Mar 1981
+S493\>422. Fix a still more serious |\gdef| bug: The generality
+	of\/ |\gdef| almost makes it a crime to
+	forget {\sl any\/} control sequence names, ever! (The previous bug was
+	only the tip of an iceberg.) @259
+I494. Issue warning message at the end of a file page if nesting level isn't zero.
+	[System dependent.]
+* 5 Mar 1981
+I495. Keep track of maximum memory usage, for statistical
+	reporting. [Obsolete.] @125
+Q496\>350. Prune away glue and penalties at top of page after marks, sends,
+	inserts. @1000
+G497. Allow |\mark| in horizontal mode. [Later it will
+	be |\vadjust{\mark...}|.] @655
+C498. Allow optional space before a required left brace, e.g., |\if AA {...}|.
+	[See \#251.] @403
+I499. Issue an incomplete |\if| error, to help catch a bad |\if|. @336
+* 17 Mar 1981
+I500\>494. Omit the warning message at end of a file page unless
+	the nesting level has changed on that page. [System dependent.]
+Q501\>310. Fix the spacing when there is a very tall subscript with
+	a superscript. @759
+* 20 Mar 1981
+S502\>371. Make space-eating after |\else| fully consistent between the
+	true and false cases. [Obsolete.]
+* 24 Mar 1981
+B503\>496. Change \\{glue_spec_size} to \\{ins_spec_size}
+	in \\{vpackage} [where insertions are done]. [Obsolete.]
+* 5 Apr 1981
+B504\>501. Fix a typo (`|+|' instead of `|-|') in the new subscript code;
+	this shifted certain subscripts down instead of up. @759
+* 18 Apr 1981
+G505. Make leaders with rules of specified size act like variable rules.
+	@626,635
+* 29 Apr 1981
+A506\>461. Don't consider $\\{badness}>\\{threshold}$ at a line |\break|
+	except in an emergency. @854
+* 13 Jul 1981
+C507\>402. Allow other characters as numbers. @442
+R508\>294. Avoid dead storage if a \\{no_new_control_sequence} error occurs.
+	[Obsolete.] @259
+G509. Add a new |\ifx| feature. @507
+G510. Add new features |\xleaders| and |\cleaders|. @626,635
+* 14 Jul 1981
+S511\>507. Amend the new code for constants;
+	the `|.|' in `|.5|' is thought to mean \O{056}! @442
+L512\>507. And fix an egregious blunder in that code: New commands at the
+	end of a procedure are ignored when earlier statements
+	exit via {\bf return}. @442
+* 4 Aug 1981
+P513. Accept alphabetic codes for all online error recovery options,
+	instead of insisting on control codes like line feed or form feed.
+	[The original error-recovery codes were suggested by the
+	conventions of the |SAIL| compiler.] @84
+G514. Add a new |\thebox| feature [later |\lastbox|]. @1079
+* 7 Aug 1981
+G515. Add |fil|, |fill|, and |filll| as units for glue stretching
+	or shrinking. @454
+I516. Suppress the overfull box error when shrinkage amount is negative. @664
+* 9 Aug 1981
+Q517. Let unset boxes inherit the size of their parent in alignments. @810
+* 12 Apr 1982
+F518. Make |INITEX| dump out the \\{font_dsize} array needed by
+	the new |DVI| output module. @1322
+* 1 May 1982
+S519\>151. Fix \\{clean_box} so that \\{mlist_to_hlist} cannot make
+	$\\{link}(q)=0$ and $\\{type}(q)=\\{glue_node}$. @720
+# [That was the historic final change to \TeX78. All subsequent entries
+	in this log refer to \TeX82.]
+* 15 Jul 1982
+# Finished draft of test program and began debugging about 1430
+	[2:30\thinspace pm]. Taking my time.
+BX1. Change \\{eqtb}[\\{cur_font}] to \\{eqtb}[\\{cur_font_loc}]. @232
+# Not logging changes to the exposition.
+# Compile time is about 2 minutes CPU, times 5 for time-sharing;
+	add another half minute for linking and loading.
+# Hash table and \\{get_next} seem to be working, with no changes needed!
+# Time out 1630--1815 for Jill's birthday party.
+LX2. Insert {\bf begin} \dots~{\bf end} around \\{dump_int} macro. @1305
+IX3. Print two blank spaces before date in \\{open_log_file}. @536
+AX4. Update $x$ and \\{var_used} outside the {\bf for} loop. @1311
+BX5. Change {\bf if} $=$ to {\bf if} $\ne$ as loop exit condition. @1315,1316
+# The |TRIP| test should preload more fonts.
+LX6. Insert {\bf begin} \dots~{\bf end} around statistics output. @1334
+FX7. Must \\{get_x_token} when scanning a number. @445
+IX8. Interactive \\{debug_help} needs to print a newline. @1338
+FX9. Include \\{ignore_spaces} and \\{math_accent} in \\{print_cmd_char} cases. @266
+IX10. Don't call \\{confusion} when \\{print_cmd_char} sees unknown code. @298
+# Compiler bug causes stack overflow. Retiring for the night at 2145.
+* 16 Jul 1982
+# Starting at 0700; DRF has fixed the compiler.
+RX11. Allow arbitrary integer parameters in diagnostic print routines. @237,699
+TX12. Say \\{cur_tok}, not \\{cur_val}, when you mean \\{cur_tok}. @440
+FX13. Make |\pause| effective also on first line of a file. @538
+FX14. Show context after online deletion. @88
+IX15. Bypass reference count when \\{debug_help} shows a token list. @1339
+BX16. Change `{\bf case} $p$' to `{\bf case} \\{type}($p$)'. @1000
+FX17. Fix timing of \\{print_ln} when scrolling help messages. @90
+PX18. Make \\{other_char} the default category for ASCII control codes too. @232
+AX19. Use special scanning method for font number in \\{new_font}. @1257
+# Eating lunch, 1020--1035, while the machine slowly recompiles everything.
+FX20. Don't forget to increase $k$ in the {\bf while} loop. @355
+DX21. Adjust \\{limit} properly after line changed when pausing. @363
+FX22. Remember to return a value in \\{new_spec} and \\{new_penalty}. @151,158
+# Now stepping through \\{line_break} in simple case.
+AX23. Don't prune unwanted nodes if $\\{cur_p}=\\{null}$. @877
+FX24. Print a closing parenthesis when displaying glue nodes. @189
+SX25. Use \\{last}, not \\{limit}, in \\{term_input}; else error prompt causes
+	trouble when $\\{state}=\\{token_list}$. @71,87
+DX26. Set $\\{first}\gets\\{limit}+1$ after \\{init_terminal}. @331
+DX27. Make sure \\{set_trick_count} is always performed. @317
+* 17 Jul 1982
+IX28. Add new diagnostic feature |\tracingcommands|. @299,1031
+# Debugging of system-dependent code not shown in this log.
+# Tangling \TeX\ now takes 1.75 minutes; about 75K bytes, 108K tokens.
+# Redundant semicolon sends Pascal compiler into infinite loop!
+FX29. Initialize $\\{passive}\gets\\{null}$. @864
+AX30. Fix pseudoprinting when the line is empty. @318
+EX31. Merge adjacent free areas of dynamic memory before dumping. @131
+FX32. Print the word |mode| in \\{print_mode}. @211
+IX33. Improve message and help in case of weird error. @415
+GX34. Allow optional space after |\def| and similar constructions. @473
+MX35. Declare \\{alpha} to be integer in \\{read_font_info}. @560
+AX36. Fix timing of \\{back_input} in \\{scan_dimen}. @448
+IX37. Back up after missing number error. @446
+IX38. Show the `|at|' size that is considered improper. @1259
+IX39. Streamline the dialog in \\{debug_help}. @1338
+MX40. Take output of \\{the_toks} from the advertised place. @467,1297
+TX41. Say \\{trie_fix}($q$), not \\{trie_fix}($p$). @959
+SX42. Decrease low limit of \\{error_count} to $-1$. @76
+* 18 Jul 1982
+FX43. Clear initial reference count of macro definitions. @473
+AX44. Fix timing of \\{back_input} in \\{scan_glue}. @461
+BX45. Use \\{cur_val_level}, not \\{cur_val}, when checking levels. @461
+BX46. Multiply |fil| units by $2^{16}$ for correct scaling. @454
+BX47. Don't confuse \\{glue_base} with \\{skip_base}. @1237
+AX48. Fix \\{print_scaled} so that 0.01 doesn't come out |0.1|. @103
+IX49\>X28. Show mode changes when tracing commands. @299
+LX50. Don't say {\bf if} $(n=0)\lor(\,\ldots\;\hbox{\bf div}\;n)$ in Pascal. @105
+BX51. Don't confuse \\{box_flag} with \\{box_code}. @1075
+SX52. Reset \\{offset} on \\{print_ln} even in \\{no_print} mode. @57
+SX53. Fix restarting of interrupts after \\{big_switch}. @1031
+LX54. Don't loop {\bf for} $k\gets a$ {\bf to} $b-1$ when $b=0$ if $k$ is
+	declared nonnegative.
+IX55. Put `|=|' sign into the \\{format_ident}. @1328
+SX56. Allow $r$ to be any integer in \\{get_node}. @125
+IX57. Don't put the output of \\{print_file_name} in quotes. @518
+IX58. Say `|dumped|' after dumping. @1311
+EX59. Eliminate unnecessary initialization code. @1332
+LX60. Get the file reading started right when beginning to undump. @1308
+IX61. Give forlorn message if format file can't be loaded. @1303
+FX62. Assign value to \\{cur_val} after glue arithmetic. @1239,1240
+* 19 Jul 1982
+LX63. Don't say {\bf if} $p>\\{max}\lor\\{free}[p]$ in Pascal. @169
+AX64. Fix memory-undump logic; loops are out of phase with input. @1312
+BX65. Undump \\{hyph_word}[$j$], not \\{hyph_word}[$k$]. @1325
+# At last |trip.fmt| loads without bombing out.
+PX66. Remove assignment of array to array, not allowed by IBM Pascal
+	(Susan Plass). @167
+PX67. Simplify an expression that's too big for IBM Pascal (Susan Plass). @1009
+AX68. Go to \\{contribute}, not \\{done}, after insertions. @1000
+IX69. Decrease \\{depth_threshold} if there's not enough string space. @198
+IX70. Show rules as `{\tt\char`\|}' in short displays. @175
+IX71. Don't show null glue in short displays. @175
+SX72. Set $\\{job_name}\gets0$ as part of output initialization. @528
+SX73. Don't complain of infinite shrinkage on |0pt minus 0fil|. @825,976,1009
+IX74. Use different prompt at beginning when accepting a file name. @37
+FX75. Reset \\{last_glue} on nonglue nodes. @996
+BX76. Remember to call \\{error} after printing |OK|. @1293
+LX77. Insert {\bf begin} \dots{ \bf end} around program text of section. @1025
+FX78. Define the |\shipout| primitive. @1071,1073
+AX79. Introduce \\{write_loc} analogous to \\{par_loc}. @1344,1371
+FX80. Dump and undump \\{par_loc} and \\{write_loc}. @1313,1314
+FX81. Allow \\{the} in \\{scan_the} [later \\{scan_something_internal}]. @413
+EX82. Interchange command codes $\\{the}:=:\\{number}$ [later \\{convert}]. @210
+BX83. Don't confuse \\{breadth} with \\{depth}. @236
+IX84. Add string printing feature to \\{debug_help}. @1339
+FX85. Set $\\{state}\gets\\{mid_line}$ in \\{begin_file_reading}. @328
+# Time out 2105--2200 to pick up Jenny from driving lesson.
+LX86. Keep $c\le127$ when deleting 99 tokens. @88
+SX87. Don't check for \\{str_room} error when $\\{selector}=\\{new_string}$. @1328
+* 21 Jul 1982
+IX88. Gather more statistics: String usage, font info, hyphen exceptions, stacks. @1334
+DX89\>X79. Initialize \\{write_loc} from \\{cur_val}, not from \\{cs_ptr}. @1344
+FX90. Remember to pack file name for |\open|. @1374
+SX91\>X34. Defuse |\outer| test before scanning optional space after `|}|'. @473
+SX92. Don't allow \\{prepare_mag} to cause errors after \\{jump_out}. @84
+# The first page of |DVI| output is {\sl perfect\/}! Pause to play piano.
+BX93. Don't confuse \\{dimen_base} with \\{scaled_base}. @1237
+DX94. Initialize $\\{link}(\\{page_head})\gets\\{null}$ when beginning a page. @991
+SX95. Correct \\{cur_height} more often, since \\{max_depth} might be negative. @972,973
+AX96. Calculate page dimensions properly after vertical kerns. @973
+SX97. Install new \\{page_contents} logic to handle interaction between
+	insertions and |\topskip|. @987,1008
+SX98. Allow \\{top_skip} glue to be a valid breakpoint. @1001
+FX99. Don't forget to count \\{dyn_used} in inner loop [erroneous analysis
+	retracted later]. @1034
+FX100. Set $p\gets q$ after migration step. @655
+FX101. Clear \\{prev_graf} to zero at start of paragraph. @1091
+LX102. Put parens into negated \\{leader_flag} macro. @1078
+# Time out 1720--1920 for John's birthday dinner.
+DX103. Scale \\{best_height} when adjusting \\{page_goal}. @1010
+AX104. Simplify logic of split insertions; three states become two. @981,1019,1020
+MX105. Don't omit first character when showing a macro argument. @400
+RX106. Prevent clobberage if macros have too many parameters. @390
+* 22 Jul 1982
+IX107. Tell how many |DVI| bytes were output. @642
+IX108\>X88. Adjust for singular or plural statistics. @1320,1334
+SX109\>X98. Consider \\{page_head} a glue node, to inhibit unwanted break. @988
+DX110. Introduce \\{new_skip_param} to keep reference counts updated. @679,969,1001
+DX111. Record the correct size of new insertion after it's split. @1010
+DX112. Use \\{free_node}, not \\{flush_node_list}, when recycling insertion
+	nodes. @1022
+SX113. Make online insertions work after \\{get_next} is interrupted. @87,324,343
+BX114. Print newline on interruption stop. @98
+SX115\>X34. Put space before \\{end_write_token}. @1371
+BX116. Don't confuse \\{glue_order} with \\{stretch_order}. @838
+TX117. Set $\\{max_dimen}\gets\hbox{\it'7777777777\/}$, not {\it'777777777}. @421
+MX118. Make |\global\textfont| legal. @1211
+BX119. Fetch |\the\textfont| with \\{equiv}, not \\{fam_font}. @415
+BX120. Call $\\{new_ligature}(f,l,\ldots)$ not $(f,c,\ldots)$. @1035
+RX121. Make \\{show_box} work on random garbage. @174,177
+DX122. Count reference to \\{zero_glue} from \\{cond_math_glue}. @1171
+* 23 Jul 1982
+RX123. Allow $\\{avail}=\\{null}$ when undumping. @1312
+BX124\>X110. Set $\\{width}(\\{glue_ptr}(p))$, not $\\{width}(p)$. @679
+AX125. Put \\{begin_file_reading} inside the \\{start_input} loop. @537
+BX126\>X116. Don't confuse \\{glue_stretch} with \\{stretch_order} [the previous
+	fix went only half\-way]. @838
+BX127. Negate $x$ when calculating badness of shrinkage. @667,678
+LX128\>X121. Remove dangling {\bf else} that parses wrong. @174
+IX129\>X28. Print newline before |{|, not after |}|, when tracing commands. @299
+IX130. Remove colon from overfull box messages. @663,675
+DX131\>X97. Compute \\{page_goal} properly when the first box arrives after
+	inserts. @1001
+BX132. Don't confuse \\{page_size} [now \\{page_goal}] with \\{best_size}. @1017
+AX133. Put heldover insertions at front of contribution list. @1023
+SX134\>X88. Output stats before closing |DVI| file, since the latter
+	decreases \\{font_ptr}. @1333
+TX135. Don't call a |\vbox| an |\hbox|. @674
+TX136. Fix misplaced {\bf end} caused by editing error. @675
+* 24 Jul 1982
+DX137. Don't \\{eq_destroy} any paragraph shape when \\{par_shape} is null. @275
+IX138. Omit blank before |\message| at the beginning of a line. @1280
+AX139\>X104. Don't try to split an insertion when \\{best_node} isn't the
+	split one. @1021
+LX140. Correct another case of `{\bf if} $x\land y$' misunderstood by Pascal.
+	@1021
+IX141. Provide diagnostic info about insertions via |\showlists|. @986
+IX142. Add `|inside a group|' to clarify a warning message. @1335
+IX143. Report \\{prev_depth} on a separate line in |\showlists|. @219
+SX144. Back up input to avoid unexpected clobberage of \\{cur_tok}. @1090
+# Wow what a bug: \\{new_graf} calls \\{build_page}, which invokes the
+	output routine, after which `\/{\bf goto} \\{reswitch}' is a {\sl disaster}.
+DX145. Add insertion glue to \\{page_so_far} instead of subtracting it from
+	the goal. @1009
+IX146. Put extra blank line before overfull box warning. @660
+CX147. Define break at kern consistently between horizontal and vertical lists. @973,1000
+DX148. Renumber so that math nodes are nondiscardable. @147
+TX149. Correct the \\{char_kern} macro: |#|, not $f$. @557
+FX150. Decrease $l$ after reconstituting discretionary break. @916
+EX151. Simplify the hyphen routine, knowing that $\\{link}(s)=\\{null}$. @918
+FX152. Initialize $r\gets q$ in discretionary destruction routine. @883
+* 25 Jul 1982
+AX153. Don't add interline penalty after last line of paragraph. @890
+IX154. Adjust spacing in diagnostic messages. @245
+DX155. Avoid simultaneous use of \\{temp_head} by \\{prune_page_top} and the
+	page builder. @1017
+FX156. Clear the \\{post_break} field of simple discretionaries. @916
+AX157. Split \\{offset} into independent variables \\{term_offset},
+	\\{file_offset}. @54,57,58
+# Am freezing current program as version $-0.25$; a week of TUG lectures
+	begins tomorrow.
+* 5 Aug 1982
+IX158. The `|.err|' file should be `|.log|' instead. @534
+GX159. Allow |\special| strings to contain more than 256 bytes. @585,1368
+MX160\>X99. Undo ``correction'' to a non-bug. @1034
+IX161. Suggest |\&| in help message for unexpected |&|. @1128
+GX162. Make `|E|' a standard option for exiting. @84
+GX163. Restore the use of dead cycles \`a la \TeX78. @1024,1054
+# The previous six changes were suggested during discussions with \TeX82 class.
+SX164. Fix global variable conflict between \\{open_log_file} and \\{new_font}. @1257
+CX165. Allow optional `|=|' when assign to font parameter. @1253
+FX166. Set \\{cur_val} after increasing the number of font parameters. @580
+DX167. Set \\{hash_brace} when matching `|{|'. @476
+IX168\>X88. Clarify meaning of statistics printed. @1334
+GX169. Change |DVI| format to include design size. @602,1260
+DX170. Introduce \\{def_ref} for \\{runaway} messages. @306
+MX171. Restore \\{cur_cs} before calling \\{scan_toks}. @1226
+AX172\>X157. Update \\{print_nl} to dual offset conventions. @62
+AX173\>X163. Move endgame logic inside \\{main_control}, because the output
+	routine becomes active. @1054
+* 6 Aug 1982
+CX174. Allow |INITEX| to load format files. @1337
+EX175. Conserve input stack space by deleting finished token lists. @325
+IX176\>X74. Print the opening `|**|' in the transcript file. @534
+# Now ready to try breaking new ground in |TRIP|.
+SX177. Preserve \\{align_state} from tokens deleted online. @88
+DX178. Set $t$ in all branches of \\{scan_toks}. @473
+SX179. Change `$\\{cur_cmd}\le\\{right_brace}$' to `$\\{cur_tok}\le
+	\\{right_brace_limit}$'; otherwise |\relax| gets through. @477
+CX180. Allow optional |=| when setting |\spacefactor|; disallow zero. @1243
+BX181. Change \\{vpackage}(\\{head}) to \\{vpackage}(\\{link}(\\{head})). @796
+# Shades of 1978!
+LX182. Insert missing {\bf begin} \dots{ \bf end}. @798
+* 7 Aug 1982
+LX183. Keep \\{trie_max} declared in non-|INITEX| [later rescinded]. @950
+DX184. Watch out for empty token list when copying. @466
+DX185. Free unused reference count slot when defining |\everypar|. @1226
+GX186\>X163. Introduce |\maxdeadcycles|. @1012
+# I believe the \\{line_break} routine has passed its test perfectly.
+SX187. Don't put discretionary after |-| inside a discretionary. @1039
+CX188. Change `|\minus|' to `|\minusthe|' [this feature retracted later]. @413
+BX189. Change \\{cur_p} to $r$ (three places). @875
+AX190. Increase range of \\{hc} to \\{halfword}; otherwise end-of-word mark
+	might match a vacant entry in the trie. @892
+FX191. Initialize $b$ in \\{shift_case} routine. @1288
+EX192. Don't back up if a space follows a decimal fraction. @452
+BX193. Don't confuse \\{glue_base} with \\{dimen_base}. @1145
+LX194. Guard against anomalous floating-point values in glue display. @186
+* 8 Aug 1982
+SX195. Avoid infinite loop when |\outer| leads to runaways. @339
+# I worked on that problem about two hours before fixing it.
+IX196. Move final \\{debug_help} to \\{succumb}, except in batch mode. @93
+RX197. Insert kern after spanned box, to defeat access to floating point. @808
+* 9 Aug 1982
+CX198. Include |\leftskip| and |\rightskip| in displayed equations [rescinded
+	later]. @1199
+IX199. Trace line-break computations if $\\{tracing_stats}>2$. @846,856
+DX200. Keep \\{prev_p} up to date when passing a string. @867
+# Now stepping through math stuff; a lot is working.
+DX201. Set $\\{link}(p)\gets z$ when making a fraction. @747
+CX202. Don't reset space factor when beginning |\valign|. @775
+IX203. Don't show glue setting if $\\{glue_sign}=\\{normal}$. @186
+DX204. Clear \\{glue_stretch} and \\{glue_shrink} when creating an unset box. @801
+BX205. Do \\{vpack} in hmode and vice versa when aligning. @804
+AX206. Remove fallacious call to \\{confusion} after alignment in display. @1206
+AX207. Don't test $\\{mode}=\\{vmode}$ in display, test $\\{nest_ptr}=1$. @1145
+FX208. Show an \\{inner_noad} as well as the other types. @690,696
+DX209. Renumber \\{mu_glue} and \\{cond_math_glue} so that the glue display logic
+	works. @149
+BX210. Don't confuse \\{cur_size} with \\{cur_style}. @703
+FX211. Advance $p\gets q$ during second pass over mlist. @761
+IX212. Add helpful hint about |\tracingonline=1|. @1293
+TX213. Delete spurious statement left from sloppy editing. @710
+DX214. Change the subtype when \\{mskip} becomes \\{hskip}. @732
+FX215. Don't forget to use the remainder when computing math glue. @716
+IX216\>X199. Improve paragraph diagnostics using \\{short_display}. @857
+IX217\>X199. Introduce \\{artificial_badness} for better diagnostics. @854,856
+* 11 Aug 1982
+AX218. Introduce \\{char_box} subroutine so that \\{var_delimiter} adds italic
+	correction. @709
+SX219. Save font and char in local variables of \\{make_math_accent}, since
+	it can be recursive. @738
+FX220. Call \\{error} after decrying an invalid character. @346
+* 12 Aug 1982
+IX221\>X199. Install new format for showing break nodes. @846
+# I have been testing \\{line_break} and I think it's working fine.
+BX222. Change $q$ to $p$, in order to catch empty alignments. @812,1206
+SX223. Disallow third part of discretionary in math mode. @1120
+DX224. Don't change \\{tail} if discretionary third part is empty. @1120
+IX225. Say |nonscript|, not |non_script|. @189
+SX226. Inhibit math if |\scriptfont3| is improper. @1195
+IX227\>X199. Introduce {\tt\@}|firstpass| and {\tt\@}|secondpass| comments. @863
+TX228. Change $p$ to $r$ when you mean $r$. @1204
+IX229\>X108. Say |page|, not |pages|, if there's only |1|. @642
+IX230. Insert space before |[]| on truncated |\showlists|. @182
+* 28 Aug 1982
+# Back from vacation after having looked at hardcopy listing of |TRIP| test.
+GX231. Allow |dm| as a unit [later |.5dm1| will be |.5\dimen1|]. @455
+IX232\>X108. Singularize |prevgraf 1 lines|. @219
+IX233. Omit trailing zero count registers when showing completed page numbers. @638
+LX234. Avoid clobbering $a$ by introducing a new local variable $t$. @986
+DX235\>X216. Fix diagnostic printing of discretionaries. @858
+IX236. Don't show unset stretch/shrink that's zero. @185
+CX237\>X198. Make |\halign| in displays consistent with other displays. (Namely,
+	ignore |\leftskip| and |\rightskip| in nonaligned displays;
+	respect the paragraph shape in aligned displays.) @800,1199
+IX238. Parenthesize `|If you're confused ...|'. @403
+IX239. Say `|\fraction|', not `|\xabovex|'. @697
+FX240. Remember to {\bf return} when you should. @1153
+PX241. Use absolute value to make sure {\bf div} is unambiguous. @737
+BX242\>X218. Don't confuse depth with height. @709
+BX243. Use $\\{delta}-\\{height}$, not $\\{height}-\\{delta}$. @736
+BX244. Increase \\{shift_down} to increase the clearance. @745
+IX245. Don't back up after improper use of |\the|. @428
+IX246. Don't give |0pt| as the default result when looking for \\{tok_val}. @428
+FX247. Initialize \\{second_indent} in the easy case. @848
+FX248. Package the equation number. @1204
+QX249. Don't resort to $v\gets\\{max_dimen}$ when glue doesn't stretch or
+	shrink. @1148
+IX250. Insert newline before showing current |\botmark|.
+FX251. Call \\{error} after giving error message. @784
+AX252. Change implementation of |\number|; it should \\{scan_int}, not
+	something internal. @471
+PX253. Introduce symbolic constants like \\{format_area_length}. @524
+PX254. Change \\{quit} to \\{jump_out}, since some compilers treat \\{quit}
+	as a reserved word. @81
+LX255. Add more parentheses to get proper parsing. @1260
+IX256. Say |please| in order to be friendly (or at least polite). @360
+BX257. Don't confuse \\{cur_vcmd} with \\{cur_chr}. @508
+IX258. Use |&| instead of |!| to specify a preloaded format. @1337
+TX259\>X177. Correct |s3| to |s4|. @88
+GX260. Introduce new primitive |\mathchardef|, to save space and time. @1224
+CX261. Use the |[]| convention for noads as well as nodes. @692
+TX262. Correct spelling in call to \\{primitive}: |\xatopx| should be |\xoverx|
+	[later renamed, thank goodness]. @1178
+* 30 Aug 1982
+RX263. Don't fetch \\{link}(\\{null}) in malformed list. @175
+SX264. Initialize \\{align_state} at a better time so that \\{align_peek}
+	doesn't see |&| or |\span|. @785,791
+SX265. Outlaw preamble interfering with $\\{align_state}=0$. @789
+CX266. Add level of grouping to alignment to tabskip locality. @774
+FX267. Check \\{align_state} when scanning $\langle u_j\rangle$. @783
+AX268. Move `\\{unsave}; \\{new_save_level}' from \\{main_control} into
+	\\{fin_col}. @791,1131
+SX269\>X180. Remember \\{cur_chr} when you're looking for optional `|=|'. @1243
+TX270. Change $q$ to $r$ [in code now obsolete]. @804
+IX271. Disable interrupts during \\{back_error} so that help messages aren't
+	clobbered. @327
+SX272. Introduce \\{slow_print} for printing control sequences. @60
+IX273. Initialize \\{del_code}(|"."|$)\gets0$ for error recovery. @240
+SX274. Call \\{end_file_reading} before calling \\{check_outer_validity}. @362
+IX275. Don't delete an extra `|}|' when |\par| will help find a runaway. @395
+* 31 Aug 1982
+BX276. Don't confuse \\{thin_muskip} with \\{thin_muskip_code}. @413
+FX277\>X266. Recover from error if new \\{align_group} ends abnormally. @1132
+IX278. Recover from error if |\par| occurs when $\\{align_state}<0$. @1094
+CX279. Make |\hskip\the\thinmuskip| and |\mskip\the\baselineskip| erroneous. @413
+GX280. Add |\muskip| and |\setmuskip| analogs to |skip| and |\setskip|. @413,1228
+EX281. Don't output |pop| right after |push|. @601
+# The |TRIP| test looks right; now to test for wasted memory.
+# When memory should be empty I find $\\{dyn_used}=18$, $\\{var_used}=267$.
+* 1 Sep 1982
+# Made special |MEMTEX| program, designed to track all memory allocation.
+DX282. Delete reference to \\{last_glue} when a page is packaged. @1017
+IX283. Include \\{save_stack} in the \\{search_mem} debugging routine. @285
+CX284. Disallow |\vfill| in restricted horizontal mode. @1095
+# Most of the memory locations I thought were wasted were actually in good use.
+# Total 192 hours (approx) debugging time so far since July 15.
+* 2 Sep 1982
+# Now looking at all zero counts in profile and extending |TRIP|.
+EX285. Simplify the creation of |vtop| boxes. @1087
+CX286. Set $\\{space_factor}\gets1000$ after |\hbox|. @1076
+PX287. Introduce preamble into |DVI| format. @617
+SX288. Give special \\{chr_code} to |\relax|. @265
+IX289. Don't show `|(null)|' when token list is null, just show nothing. @295
+EX290. Delete the procedure \\{write_name_string}, which is never used.
+CX291. Rename |\xabovex| to |\abovewithdelims|; do the same for
+	|\xatopx| and |\xoverx|. @1178
+QX292. Improve \\{clean_box} so that it recognizes cleanliness better. @720
+IX293. Report a |Missing delimiter| more meaningfully. @1161
+RX294. Give \\{endv_token} a \\{chr} code of 128 so that it will end a file name. @289
+RX295. Test present of math fonts {\sl after\/} parsing an mlist, not
+	before. @1138,1195
+IX296. Omit `|recent contributions|' and/or `|current page|' when they are
+	empty. @218,986
+IX297. Display what \TeX\ has deleted after improper discretionary list
+	has arisen. @1121
+IX298. Show what math character was undefined. @723
+IX299. Improve the |Incompatible magnification| error; break it into two lines. @288
+DX300. Put new cases into \\{flush_node_list}, to recycle mlist noads. @698
+* 6 Sep 1982
+FX301\>X300. Insert a necessary `{\bf goto} \\{done}' in that new material. @698
+# It took two hours to diagnose that {\bf goto} problem.
+TX302\>X295. Change `|2|' to `|3|' in help message for extension fonts. @1195
+IX303. Add a special note if material is being held over for the next output. @986
+RX304. Divide before multiplying in \\{make_left_right}, to avoid overflow. @762
+IX305. Introduce the \\{box_error} routine. @992
+FX306. Clear \\{arith_error} after overflow has been reported. @460
+BX307\>X249. Don't confuse \\{stretch} with \\{glue_stretch}. @1148
+DX308. Set $\\{glue_sign}\gets\\{normal}$ when packaging with glue ratio
+	zero. @558,664
+AX309. Test for overflow before attaching the sign. @448
+# That all worked! Now trying |min_quarterword| negative.
+LX310. Take absolute value before applying {\bf mod} in \\{new_trie_op}. @944
+LX311. Say $\\{qi}(c)$, not $c$, when testing |TFM| flags [now obsolete]. @573
+LX312. Initialize \\{token_ref_count}(\\{def_ref}) to \\{null}, not zero. @473
+LX313. Change the type of \\{vsplit} parameter $n$ from \\{quarterword} to
+	\\{eight_bits}. @977
+LX314. Initialize \\{null-delimiter} different form \\{null_character}. @685
+LX315. Insert \\{qi} twice in \\{scan_delimiter}. @1160
+FX316. Insert \\{qi} in \\{scan_math}. @1151
+FX317. Insert \\{qo} in \\{fetch}. @722,723
+FX318. Insert \\{qi} in \\{set_math_char}. @1155
+FX319. Insert \\{qi} in \\{math_ac}. @1165
+FX320. Insert \\{qo} in \\{mlist_to_hlist}. @755
+IX321. Use brackets around 8-bit characters in \\{print_ASCII}. @68
+IX322. Include \\{hyph_list} in the \\{search_mem} debugging routine. @933
+# Now compiling non-|INITEX| to try an industrial-strength version.
+LX323. Add {\bf return} to \\{final_cleanup}, because some Pascal compilers
+	insist that each label be used. @1335
+DX324. Compute \\{par_token} when undumping. @1314
+* 11 Sep 1982
+IX325. Emit newline before file name, if near end of line. @537
+CX326. Define |\ifx| for arbitrary tokens. @507
+* 12 Sep 1982
+IX327. Don't ask users to type |x| twice before exiting. @84
+GX328. Install new features |\openin|, |\read|, |\ifeof|, |\closein|; rename
+	existing |\open|, |\send|, |\close| to be |\openout|, |\write|,
+	|\closeout|. @209,313,1275
+GX329. Install new feature |\expandafter|. @368
+PX330. Change the default file area from `|<TeX>|' to `|TeXinputs:|'. @574
+* 13 Sep 1982
+GX331. Install new feature |\string|. @472
+AX332. Remove spurious space printed by \\{sprint_cs}. @263
+# All tests passed now! But when I played with the system I found another bug
+	(undetected by |TRIP|):
+FX333. Set $r\gets s$ after matching macro parameter tokens. @397
+* 16 Sep 1982
+IX334\>X199. Introduce serial numbers in line-break records, improving
+	readability and independence. @846
+IX335. Don't abort when \\{file_name_size} is exceeded. @519
+* 17 Sep 1982
+IX336. Remove unwanted period from font capacity message. @567
+* 18 Sep 1982
+GX337\>X329. Make |\expandafter| more powerful by moving it from semantics
+	to syntax [i.e., from stomach to mouth]. @368
+* 19 Sep 1982
+IX338. Improve error recovery for `|Missing number|'. @415
+* 22 Sep 1982
+QX339. Suppress italic correction between letters in math mode except in math
+	fonts. @752
+* 24 Sep 1982
+PX340. Define $\\{null}=\\{mem_bot}$, not \\{min_halfword}, because there's
+	a reference to \\{link}(\\{null}) in \\{try_break}. @115
+DX341. Initialize $\\{str_start}[0]\gets0$. @47
+IX342. Avoid blank space at beginning of line. @638
+DX343. Set type of new box in math mode to \\{ord_noad}, not \\{inner_noad}. @1076
+* 28 Sep 1982
+# Here are the first changes made to the preliminary listing of \TeX82 that was
+	published by the \TeX\ project earlier this month.
+F520. Insert the missing cases \\{letter} and \\{other_char} after
+	\\{x_token} looks ahead. @1038
+C521. Change `|\pause|'  to `|\pausing|'. @236
+D522. Reset \\{overfull_rule} when determining tabskip glue. @804
+A523. Fix the logic for scanning |\ifcase| [in obsolete syntax---everything
+	is still done with braces since `|\fi|' doesn't exist yet]. @509
+* 30 Sep 1982
+I524. Change |"0.0"| to |"?.?"| (suggested by DRF). @186
+* 2 Oct 1982
+Q525. Use conditional thin spacing next to `Inner' noads. @764
+Q526. Make thick spaces conditional. @766
+* 4 Oct 1982
+P527. Increase \\{trie_size} from 7000 to 8000, because of Frank Liang's improved
+	(but longer) hyphenation patterns. @11
+* 6 Oct 1982
+F528\>X330. Change the string lengths to match the new \\{\TeX_format_default}. @520
+# Version 0 of \TeX\ is being released today!
+* 8 Oct 1982
+B529. Fix a blunder: I decreased $h$ mod a quarterword when it should have
+	been decreased mod \\{trie_op_hash_size} (HWT). @944
+* 9 Oct 1982
+P530\>X258. Fix a typo (`|!|' not `|&|') in the |WEB| documentation. @524
+F531. Remember to call \\{initialize} if a different format was preloaded
+	(Max D{\'\i}az). @1337
+# Version 0.1 incorporates the above changes.
+* 12 Oct 1982
+G532. Add the `|\immediate|' feature, by popular request. @1375
+# Version 0.2 incorporates this (somewhat extensive) change.
+* 13 Oct 1982
+P533. Introduce new |WEB| macros so that \\{glue_ratio} is more easily changed. @109
+# I began writing {\sl The \TeX book\/} today: edited the old preface and
+	searched in the library for quotations.
+* 14 Oct 1982
+B534. Change the type of \\{hd} to \\{eight_bits}; it's
+	not a \\{quarterword} (HWT). @649
+S535\>X281. Revise the optimization of\/ |DVI| commands: It's not always safe to eliminate
+	\\{pop} when the preceding byte is \\{push}, since |DVI| commands
+	have variable length! (Embarrassing oversight caught by DRF.) @601
+* 15 Oct 1982
+C536. Test `$\\{prev_depth}>\\{ignore_depth}$', not `$\ne$'. @679
+# Version 0.3 incorporates the above changes.
+* 16 Oct 1982
+P537. Omit definition of \\{align_size}; it's never used (Bill Scherlis). @11
+I538. Inhibit error messages when packaging box 255. @1017
+* 21 Oct 1982
+A539\>X145. Subtract $\\{width}(q)$ from \\{page_goal}, don't add it to
+	$\\{page_so_far}[1]$. @1009
+# Version 0.4 incorporates the above changes.
+* 22 Oct 1982
+P540. Increase the amount of lower (variable-size) memory from 12000 to 13000,
+	since the \TeX\ program listing now needs about 11500. [At this time
+	there still is a fixed boundary between upper and lower memory.] @12
+G541. Add a new parameter |\boxmaxdepth|. @1086
+# Version 0.5 incorporates the above changes.
+* 26 Oct 1982
+B542. Fix an off-by-one error caught by Gabi Kuper and HWT.
+	(I forgot `${}+1$'). @1317
+B543. Fix the spacing of displayed control sequences: \\{print_cs} should base its
+	decision on $\\{cat_code}(p-\\{single_base})$, not $\\{cat_code}(p)$. @262
+# The |TRIP| test detected this bug, but I didn't notice.
+* 27 Oct 1982
+S544. Set \\{math_type} before saying $\\{fetch}(\\{nucleus}(q))$, since
+	fetching can have a side effect. @752
+* 28 Oct 1982
+G545. Install a major change: Fonts now have identifiers instead of code letters.
+	Eliminate the `|\:|' primitive, and give corresponding new
+	features to `|\the|'. @209
+# Actually I began making these changes on October 26, but I needed two days
+	to debug them and to put Humpty Dumpty together again.
+# At this time I'm also drafting macros for typesetting {\sl The \TeX book}.
+# The above changes have been incorporated into Version 0.6.
+* 30 Oct 1982
+# After years of searching, I've finally found a definitive definition of
+	the printer's point; and (unfortunately) my previous conjecture was
+	wrong. The truth is that $\rm83\,pc=35\,cm$, exactly;
+	so I am changing \TeX\ to conform.
+C546. Revise unit definitions for the `real' printer's point. @458,617
+# Version 0.7 incorporates the above.
+* 1 Nov 1982
+# Oops! Retract error \#546, and retract \TeX\ Version 0.7;
+	the source of my information about points was flaky after all.
+	My original suppositions were correct,
+	as confirmed by NBS Circular 570.
+* 4 Nov 1982
+C547. Revise the definition of |dd|, conforming to the definitive value
+	shown me by Chuck Bigelow. @458
+R548\>545. Introduce ``frozen'' copies of
+	font identifiers, to be returned by |\the\font|, so that font
+	manipulation is more robust. @1257
+* 5 Nov 1982
+D549. Reset \\{looseness} and paragraph shape when beginning a |\vbox|. @1083
+* 6 Nov 1982
+D550. De-update \\{align_state} when braces are in constants. @442
+I551\>X294. Improve error recovery for bad alignments. @1127
+# Today I wrapped up Chapters 4 and 5.
+* 8 Nov 1982
+G552. Give more power to |\let|: the right-hand side needn't be a control
+	sequence. @1221
+I553. Amend \\{show_context} to say
+	`$(\\{base_ptr}=\\{input_ptr})\lor{}$'; otherwise undefined control
+	sequences can be invisible in unusual cases (John Hobby). @312
+A554. Compute demerits more suitably by adding a penalty squared, instead of
+	adding penalties before squaring. @859
+# Previously a slightly loose hyphenated line followed by a decent line
+	was considered worse than a decent hyphenated line followed by
+	a quite loose line.
+* 10 Nov 1982
+E555. Save a bit of buffer space by declaring \\{pool_file} only in
+	|INITEX|. @50
+* 11 Nov 1982
+I556. Introduce a new context indicator to clarify \TeX's scanning state:
+	A special type
+	called \\{backed_up} is distinguished from other kinds of \\{inserted}
+	lists; it is called `recently read' or `to be read again', while
+	others are called `inserted'. @314
+I557. Append a comment, `|treated as zero|', to the missing-number message. @446
+I558. Ignore the settings of\/ |\hfuzz| or |\vfuzz| if\/ |\hbadness| or |\vbadness|
+	is less than 100. @666,677
+* 13 Nov 1982
+# Major surgery on the program is planned for today, because of new ideas
+	suggested by correspondence with MDS and other macro writers.
+G559. Introduce a new |\tokens| register; this will be useful and easy to add,
+	since \TeX\ already can handle |\everypar| and |\output|. @1227
+C560\>X34. Change \\{get_x_token} to \\{get_token} when scanning an optional
+	space; then a construction like
+	|\def\foo{...}\foo| won't complain that |\foo| is undefined. @443
+# This change was retracted when it was being debugged, because it could
+	cause \\{endv} to abort the job. Then it was re-established again
+	when I found that \\{endv} needed to be more robust anyway.
+	[But it was eventually rescinded again.]
+G561. Make |\span| mean `expand' in a preamble. @782
+E562. Use three separate {\bf if\/} tests instead of
+	`$\land$' in the inner loop of \\{get_next}, to gain efficiency. @342
+R563. Introduce \\{get_r_token} so that assignments have uniform error
+	messages and so that frozen equivalents cannot be changed. @1215
+# I gave a few variables more mnemonic names as I made these changes.
+C564. Move conditional statements from the semantics (`stomach') part of
+	\TeX\ to the syntax (`mouth') part, by introducing `|\fi|'.
+	Also introduce |\csname| and |\endcsname|. @372,489\hbox{--}500
+# This makes macros much more predictable and logical, but it is by far
+	the most drastic change ever made to \TeX. The program began to come
+	back to life only after three days of solid hacking.
+# Several other things were cleaned up as part of this change
+	because it is now more natural to handle them differently.
+	For example, a null control sequence has now become more logical.
+# The result of all this is called Version 0.8.
+* 18 Nov 1982
+# Today I resumed writing Chapter 8. Tomorrow I'm $\,2^{14}$ days old!
+* 21 Nov 1982
+F565. Declare $c$ as a local variable for hyphenation (DRF). @912
+E566. Omit the ``first pass'' and try hyphenations immediately,
+	if\/ |\pretolerance| is negative (suggested by DRF). @863
+R567. Don't ship out incredibly huge pages; they might foul up
+	|DVI| files. @641
+* 2 Dec 1982
+G568. Add new features |\everymath| and |\everydisplay|. @1139,1145
+G569. Add a new feature |\futurelet|. @1221
+# The changes above have been incorporated into Version 0.9 of \TeX.
+* 7 Dec 1982
+G570. Add a new |\endinput| primitive (suggested by FY). @362,378
+* 8 Dec 1982
+I571. Try \\{off_save}, if\/ |\par| occurs in restricted horizontal mode.
+	(This avoids embarrassment if \TeX\ says `type a command or
+	say |\end|', then when you type |\end| it says you can't!)
+	[However, I soon retracted this change.] @1094
+* 21 Dec 1982
+A572. Redefine |\relax| so that its \\{chr} field exceeds 127. (This facilitates
+	the test for end in \\{scan_file_name}.) @265
+F573\>566. Call \\{begin_diagnostic} when omitting
+	the first pass of line breaking. @863
+A574. Fix the logic of glue scanning: In |\hskip-1pt plus2pt| the minus should
+	apply only to the |1pt|. @461
+* 23 Dec 1982
+I575. Renumber the decimal codes in paragraph statistics for loose and tight
+	lines; they were ordered backwards. @817
+C576. Treat a paragraph that ends with leaders like a paragraph that
+	ends with glue. @816
+C577. Allow commas as alternates to radix points, for Europeans. @438
+C578. Change |\hangindent| to a normal dimension parameter. [It had been
+	a combination of\/ |\hangindent| and |\hangafter|, with special
+	syntax.] @247
+G579. Make |\prevgraf| accessible to users. @422,1244
+G580. Split |\clubpenalty| off from |\widowpenalty|. @890
+# I'm typing Chapter 14 while making these changes.
+* 24 Dec 1982
+S581. Use \\{back_input} instead of {\bf goto} \\{reswitch} when
+	inserting |\par|, because |\par| may have changed. @1095
+* 25 Dec 1982
+# It's 10pm after a very Merry Christmas!
+I582\>X328. Don't prompt for a new file name if\/ |\openin| doesn't find a file. @1275
+G583. Add a new |\jobname| primitive. @472
+I584. Give the user a way to delete the dollar sign, when \TeX\ decides
+	to insert one. @1047
+C585. Allow optional equals after |\parshape|, and implement |\the\parshape|.
+	@423,1248
+* 26 Dec 1982
+I586. Add an \\{if_line_field} to the condition stack entries,
+	so that more informative error messages can be given. @489
+D587\>549. Introduce a \\{normal_paragraph} procedure, since initialization is needed
+	also within |\insert|, |\vadjust|, |\valign|, |\output|. @1070
+* 27 Dec 1982
+G588. Give users access to |\pagetotal| and |\pagegoal|. (Analogous to
+	\#679 and \#585, but simpler.) @1245
+I589\>X199. Introduce |\tracingpages|, allowing users to see
+	page-optimization calculations. Also split |\tracingparagraphs| off from
+	|\tracingstats|. @987,1005,1011
+# The changes above have been incorporated into Version 0.91 of \TeX.
+* 31 Dec 1982
+P590. Break the \\{build_page} procedure into two parts, by extracting
+	the section now called \\{fire_up}. [This is necessary because
+	some Pascal compilers, notably for IBM mainframes, cannot
+	deal with large procedures.] @1012
+S591\>564. Make |\ifodd1\else| legal by introducing \\{if_code}. @489
+Q592. Improve alignments when columns don't occur: Don't append null boxes
+	for columns missing before |\cr|, and zero out the tabskip
+	glue after nonpresent columns. @802
+I593. Make the error message about overfull alignment more intelligible.
+	@801,804
+# The changes above have been incorporated into Version 0.92 of \TeX82,
+	which was the last version of 1982,
+	completed at 11:59pm on December 31.
+* 3 Jan 1983
+# Today I'm beginning to write Chapter 15, and
+	planning the |\output| routine of |plain.tex|.
+C594\>X186. Change the logic of \\{its_all_over}; use \\{max_dead_cycles}
+	here too, instead of the fixed constant~100. @1054
+F595\>X34. Don't forget to \\{pop_nest} when an insert is empty. Also disallow
+	optional space after |\insert|$\,n\,$|{...}|. @1100
+* 4 Jan 1983
+C596\>541. Use the |\boxmaxdepth| that's declared inside a |\vbox| when packaging it.
+	@1086
+C597. Rename |\groupbegin| and |\groupend| as |\begingroup| and
+	|\endgroup|. @265
+G598\>594. Make |\deadcycles| accessible to users. @1246
+Q599. Base the split insertions on natural height plus depth, not
+	on \\{delta}. @1010
+# The changes above have been incorporated into Version 0.93.
+* 6 Jan 1983
+D600. Add \\{push_math} to handle a case where I forgot
+	to clear \\{incompleat_noad}. (This long-standing bug was
+	unearthed today by Phyllis Winkler.) @1136
+G601\>588. Add |\pageshrink|, etc., too. @1245
+G602. Introduce new parameters |\floatingpenalty|, |\insertpenalties|. Also
+	adopt a new internal representation of insertion nodes,
+	so that |\floatingpenalty|, |\splittopskip| and |\splitmaxdepth|
+	can be stored with each insertion. @140,1008
+* 7 Jan 1983
+Q603. Improve the rules for entering \\{new_line}, in particular
+	when the end-of-line character is active. @343
+* 9 Jan 1983
+Q604. Distinguish between implicit and explicit kerns. @155,896
+C605. Change the name |\ignorespace| to |\ignorespaces|. @265
+C606\>560. Don't omit a blank space after |\def|, |\message|, |\mark|, etc.;
+	the previous hodge-podge of rules is impossible to learn. @473
+# The above changes appear in Version 0.94.
+* 12 Jan 1983
+# Beginning to write the chapters on math today.
+G607. Add a new feature: active characters in math mode. @1151
+* 15 Jan 1983
+A608. Fix a surprise bug: `|$1-$|' treated the |-| as binary. @729
+D609. Initialize \\{space_factor} inside discretionaries. @1117
+* 16 Jan 1983
+F610. Fix an incredibly embarrassing bug: I forgot to update \\{spotless} in the
+	\\{error} routine!
+# While fixing this, I decided to change
+	\\{spotless} to a more general \\{history} variable, as suggested
+	by IBMers who want a return code. @76,82,1335
+I611. Replace two calls of \\{confusion} by attempts at error recovery, in places
+	where `|This can't happen|' could actually happen. @1027,1372
+* 18 Jan 1983
+R612. Introduce the \\{normalize_selector} routine
+	to protect against startup anomalies
+	when the transcript file isn't open. Also make \\{open_log_file}
+	terminate in some cases. @92,535
+R613\>591. Insert |\relax|, not a blank space, to cure infinite
+	loop like |\ifeof\fi| (LL). @510
+G614. Change the old |\limitswitch| to |\limits|, |\nolimits|, and
+	|\displaylimits|. Incidentally, this fixes a bug in the former
+	positioning of integral signs. @682,749
+C615. Give a |\char| in math mode its inherited |\mathcode|. @1151
+Q616\>525. Make underline, overline, radical, vcenter, accent noads and |{...}|
+	all revert to type Ord instead of type Inner. Introduce a new primitive
+	|\mathinner|. (This fixes the spacing, which
+	got worse in some ways after change \#525.) @761
+# I'm working on Appendix G today.
+* 19 Jan 1983
+G617. Introduce a |\mathchoice| primitive. @1174
+C618. Move |\input| from the stomach to the mouth. @378
+C619\>X260. Introduce |\chardef|, analogous to |\mathchardef|. @1038,1224
+G620. Change |\unbox| to |\unhbox| and |\unvbox|; also add |\unhcopy|. @1110
+C621. Consider |\spacefactor|, |\pagetotal|, etc., as part of
+	\\{prefixed_command}, even though they are always global. @1211
+* 20 Jan 1983
+C622. Switch modes when |\hrule| occurs in horizontal mode or |\vrule|
+	in vertical. @1090,1094
+G623. Add a new |\globaldefs| feature. @1211
+* 21 Jan 1983
+E624. Optimize the code, in places where it's important (based on
+	frequency counts of \TeX\ usage
+	accumulated during the past week): Introduce \\{fast_get_avail}
+	and \\{fast_store_new_token}; reduce procedure-call overhead
+	in \\{begin_token_list}, \\{end_token_list}, \\{back_input},
+	\\{flush_node_list}; change some tests from `{\bf if} $a\land b$' to
+	`{\bf if}~$a$ {\bf then if}~$b$'. @122,371
+* 22 Jan 1983
+E625. Save space in math lists: Don't insert penalties within restricted
+	horizontal mode; simplify trivial boxes. @721,1196
+S626. Fix a surprising oversight in the \\{rebox} routine:
+	Ensure that $b$ isn't a vbox. @715
+C627\>545. Make |\nullfont| a primitive, so that \\{cur_font} always
+	has a value. (This is a dramatic improvement over \TeX78, where a
+	missing font was a fatal error called `|Whoa|'!) @552
+* 24 Jan 1983
+I628\>586. List all incomplete |\if|'s when the job ends. @1335
+* 29 Jan 1983
+C629\>552. Change initialization of \\{align_state} so that |\halign\bgroup|
+	works. @777
+* 30 Jan 1983
+D630\>625. Be sure to test `\\{is_char_node}($q$)' when checking for a trivial
+	box. @721
+# By extraordinary coincidence, this bug was caught when somebody
+	used font number~11 ($=\\{kern_node}$) in the second character
+	of a list of length~2!
+I631\>X168. Improve format for stats at end of run, as suggested by DRF. @1334
+# The changes above have been incorporated into Version 0.95.
+C632. Don't ignore the space after a control symbol (except `|\ |'). @354
+P633. Remove all trailing spaces at the right of input lines,
+	so that there's perfect compatibility with IBM systems that
+	extend short lines with spaces. @31
+* 3 Feb 1983
+I634. Assume that a \\{math_accent} was intended, after giving an error
+	message in the case $\\{mmode}+\\{accent}$. @1165
+G635. Add new primitives |\iftrue| and |\iffalse|. @488
+* 6 Feb 1983
+A636\>X304. Improve the accuracy of fixed-point arithmetic when
+	calculating sizes for |\left| and |\right|. (I had started by
+	dividing \\{delimiter_factor}, not \\{delta1}, by 500.) @762
+* 12 Feb 1983
+C637. Change the name |\delimiterlimit| to |\delimitershortfall|. @248
+C638. Make |\abovewithdelims..| equivalent to |\above|; change the
+	order of operands so that delimiters precede the dimension. @1182
+C639\>607. Remove the kludgy math codes introduced earlier;
+	make |\fam| a normal integer parameter and allow |\mathcode|
+	to equal $2^{15}$. @1233
+R640. Don't let |\spacefactor| become more than $2^{15}$. @1233,1243
+# I finished drafting Chapter 17 today.
+* 14 Feb 1983
+I641\>639. Replace octal output (\\{print_octal}) by hexadecimal (\\{print_hex})
+	so that math codes are clearer. @67
+F642\>619. Don't forget \\{char_given} in the \\{math_accent} routine. @1124
+* 17 Feb 1983
+C643\>622. Switch modes when |\halign| occurs in horizontal mode, or |\valign|
+	in vertical mode. @1090,1094
+* 18 Feb 1983
+I644. Add a new feature |\tracingrestores|. This requires a new procedure called
+	\\{show_eqtb}, whose code can be
+	interspersed with the \\{eqtb} definitions. @252
+* 25 Feb 1983
+I645\>622. Suggest using |\leaders| when the user tries a horizontal rule
+	in restricted horizontal mode. @1095
+* 27 Feb 1983
+I646. Specify the range of source lines, when giving warning messages
+	for underfull or overfull boxes in alignments. @662,675
+# Why did it take me all day to type the middle part of Chapter 18?
+* 4 Mar 1983
+G647. Introduce a new feature |\xcr| (suggested by LL). [Changed later to
+	`|\crcr|'.] @785
+I648\>631. Subtract out \TeX's own string requirements from the stats. @1334
+* 6 Mar 1983
+G649. Add new features |\everyhbox| and |\everyvbox|. @1083,1167
+* 9 Mar 1983
+R650\>X295. Avoid accessing \\{math_quad} when the symbol fonts aren't known
+	to be present. @1199
+P651\>533. Introduce \\{float} and \\{unfloat} macros to aid portability (HWT). @109
+C652. Introduce new names |\abovedisplayskip| and |\belowdisplayskip| for
+	the old |\dispskip|; also |\abovedisplayshortskip| and
+	|\belowdisplayshortskip| for the old |\dispaskip| and |\dispbskip|. @226
+* 10 Mar 1983
+C653. Unbundle |\romannumeral| from |\number| (suggested by FY). @468
+* 12 Mar 1983
+C654. Ignore leading spaces in \\{scan_keyword}. @407
+* 14 Mar 1983
+E655\>631. Use \\{write} and \\{write_ln} directly when printing stats. @1334
+* 16 Mar 1983
+Q656\>602. Refine the page-break cost function (introducing `\\{deplorable}',
+	which is not quite `\\{awful_bad}'), after suggestion by LL. @974,1005
+# The changes above have been incorporated into Version 0.96.
+* 18 Mar 1983
+G657. Add a new feature |\everyjob| suggested by FY. @1030
+* 19 Mar 1983
+I658. Don't treat left braces specially when showing macros. @294
+C659. Ignore blanks that would otherwise become undelimited arguments. @393
+* 21 Mar 1983
+F660\>X280. Make |\lastskip| handle \\{mu_glue} as well as ordinary glue. @424
+C661\>561. Expand only one level in a preamble |\span|. @782
+* 22 Mar 1983
+C662. Let a single |#| suffice in |\tokens|, |\message|, etc. (The previous rule,
+	in which |##| was always required as in macros, was a loser especially
+	in |\write| where you had to say |####|!) @477
+C663\>X328. Require the keyword `|to|' in |\read|. (This will avoid the common error
+	of an incomplete constant when no space appears
+	before the |\cs|.) Also allow terminal
+	I/O as a default when a stream number is out of range. @482,1225,1370
+* 26 Mar 1983
+C664. Replace |\ifeven|\<countnumber> by |\ifodd|\<number>, for better
+	consistency of language. @504
+S665\>564. Introduce the \\{change_if_limit}, to overcome a big surprise
+	bug relating to |\if\if aabc\fi|. @497
+# Such examples show that \\{cur_if} might not be current,
+	in my original implementation.
+* 28 Mar 1983
+G666\>X326. Tolerate non-characters as arguments to |\if| and |\ifcat|. @506
+C667. Change `|absent|' to `|void|', a better word. @487
+C668. Clear the \\{shift_amount} in |\lastbox|, since I don't
+	want to figure out what it means in all cases. @1081
+* 29 Mar 1983
+I669. Wake up the terminal before giving an error message. (This
+	means a special \\{print_err} procedure is introduced.)
+	(Suggested by DRF.) @34,73
+* 1 Apr 1983
+# Today I finished Chapter 21 (boxes) and began to draft Chapter 22 (alignments).
+G670. Allow periodic preambles in alignments. @793
+C671. Make |\leaders| line up according to the smallest
+	enclosing box. @627,636
+Q672. Allow hyphenation after whatsits (e.g., after items for an index). @896
+* 2 Apr 1983
+Q673. Call \\{build_page} when |\par| occurs in vertical mode. @1094
+C674. Clear \\{aux} in \\{init_row}, for tidyness. @786
+* 4 Apr 1983
+C675. Let digits switch families in math mode. @232
+* 7 Apr 1983
+Q676\>602. Refine the test for not splitting an insertion. @1008
+* 8 Apr 1983
+C677\>647. Rename |\xcr| as |\crcr|, at LL's request. @780
+* 9 Apr 1983
+# Took a day off and had a chance to help print a sample page on
+	a 150-year-old letterpress in Murphys, California.
+* 11 Apr 1983
+I678. Recover more sensibly after a runaway preamble. @339
+* 12 Apr 1983
+C679\>X328. Make |\read| span several input lines, if necessary to get
+	balanced braces. @482
+* 14 Apr 1983
+S680. Fix a subtle bug found by JS: \S882 can make $q$ a \\{char_node},
+	so we need to test `{\bf if} $\lnot\\{is_char_node}(q)$'.
+	[Actually I discovered much later that the real bug was
+	to omit `{\bf else}' at this point.] @881
+* 15 Apr 1983
+C681. Make |\uppercase| and |\lowercase| apply to all characters, regardless
+	of category. @1289
+# 7:30am. After working all night, I completed a draft of the manual thru
+	Chapter 22, for distribution to volunteer readers.
+# 5pm. The changes above have been incorporated into Version 0.97.
+* 17 Apr 1983
+R682. Change `\\{small_number}' to `$0\,.\,.\,65$' in the
+	hyphenation routine (DRF). @901
+I683. Flush patterns in the input when the user tries |\patterns|
+	outside of\/ |INITEX| (suggested by DRF). @1252
+# Tomorrow I fly to England, where I'll lecture and write a paper about
+	`Literate Programming' [{\sl Comp.~J. \bf27} (1984), 97--111].
+* 14 May 1983
+I684\>663. Improve the behavior of\/ |\read| from terminal
+	(suggested by Todd Allen at Yale).
+	[I'd forgotten to implement the extended stream numbers in \#663.
+	Also, the prompt is now omitted if $n<0$.] @484
+* 18 May 1983
+I685. Restrict |\write| $n$ to the transcript file only, if $n<0$. @1350
+C686\>X188. Unify the syntax for registers and internal quantities. (Remove
+	primitives called `|\insthe|' and `|\minusthe|'; rename
+	\\{scan_the} to \\{scan_something_internal}, and change its
+	interface accordingly; clean up command codes generally.) @209,413
+G687. Introduce new parameters |\hoffset|, |\voffset|. @617
+* 24 May 1983
+G688. Introduce a new parameter |\everycr| (suggested by MDS). @774,799
+# Many macro writers and preliminary-manual readers have been requesting
+	new features; I'll try to keep the language as concise and consistent
+	as possible.
+* 25 May 1983
+G689. Introduce |\countdef|, |\dimendef|, etc.\ (suggested by DRF long ago,
+	easy now in view of \#686). @1224
+G690. Introduce |\advance|, |\multiply|, |\divide| (suggested by FY). @1240
+G691. Introduce |\hyphenchar|; this requires a new command
+	\\{assign_font_int}, plus minor changes to about 15 modules. @915
+G692. Introduce |\skewchar| (easy because of \#691). @741
+G693. Introduce |\noexpand|. (I had difficulty thinking of how to
+	implement this one!) @358,369
+G694. Introduce |\meaning|. @296
+G695\>X231. Remove `|dm|' and `|vu|'; allow the more general `|.5\hsize|'. @455
+C696. Change `|\texinfo| $f$ $n$' to `|\fontdimen| $n$ $f$'. @578
+* 27 May 1983
+G697. Add a new feature |\afterassignment| (suggested by ARK). @1269
+C698\>619. Adjust the timing so that commands like `|\chardef\xx=5\xx|'
+	behave sensibly. @1224
+* 28 May 1983
+C699. Ignore `|\relax|' as if it were a space, in math mode and in a few other
+	places where |\relax| would otherwise be erroneous. @404
+Q700. Improve |\mathaccent| spacing with respect to subscripts
+	and superscripts (suggested by HWT). @742
+* 30 May 1983
+C701\>598. Terminate a job only when $\\{dead_cycles}=0$. @1054
+# The changes above constitute Version 0.98.
+* 3 Jun 1983
+# I finished the draft of Chapter 23 (output routines) today.
+G702. Allow |\mark| and |\insert| and |\vadjust| in restricted
+	horizontal mode, and also in math mode. (This is a comparatively
+	big change, triggered by the fact that |\mark| in a display
+	presently causes \TeX\ to crash with `|This can't happen|'!)
+	The global variable \\{adjust_tail} is introduced. @796,888,1085
+* 6 Jun 1983
+G703\>695. Replace (and generalize) the previous uses of\/ |ht|, |wd|, and |dp|
+	in dimensions by introducing the new control sequences
+	|\ht|, |\wd|, and |\dp|. @1247
+I704. Display sub-parts of noads with the symbols |^| and |_| instead of
+	|(| and~|[|. @696
+C705\>694. Allow |A..F| in hex constants to be \\{other_char} as well as
+	\\{letter}. @445
+* 7 Jun 1983
+E706\>654. Remove an instance of \<Scan optional space>, since it's now
+	redundant. @457
+C707. Legalize |\mkern\thinmuskip| and |\mkern5\thinmuskip|. @456
+C708. Clean up the treatment of optional spaces in numerical specifications. @455
+# A construction like |2.5\space\space\dimen0| was previously
+	valid after `|plus|' or `|minus|' only!
+# I'm obviously working on Chapter~24 today.
+C709\>545. Allow `|\font|' as a \<font identifier> for the current font. @577
+C710\>623. Don't make |\gdef| global when $\\{global_defs}<0$. @1218
+E711. Produce \\{zero_glue} as the outcome of
+	|\advance\spaceskip by-\spaceskip|. @1229
+I712. Make |\show| do something appropriate for every possible token. @1294
+G713\>559. Replace the (single) |\tokens| parameter by an array of
+	256 token registers. @230
+C714. Allow |\indent| in math mode; also make |\valign| in math mode produce the
+	`|Missing|~|$|' error. @1046,1093
+E715. Remove redundant code: There's no need to check \\{cur_group}
+	or call \\{off_save} when starting alignments or equation numbers
+	in displays. @1130,1142
+* 8 Jun 1983
+C716. Disallow |\openout-1| and |\closeout-1|. @1350
+C717. Disallow |\lastbox| in math mode. @1080
+* 9 Jun 1983
+I718. Call \\{back_error}, not \\{error}, when |\leaders| aren't followed by
+	proper glue. @1078
+D719. Initialize for a possible paragraph, after |\noalign|
+	in a |\valign|. @785
+* 10 Jun 1983
+C720\>708. Expand the optional space after an ASCII constant. @442
+* 12 Jun 1983
+C721. Set $\\{space_factor}\gets1000$ after a rule or a
+	constructed accent. @1056,1123
+* 14 Jun 1983
+D722. Correct a serious blunder: Set $\\{disc_width}\gets0$ before testing
+	if $s$ is null (caught by JS). @869
+# This is a real bug that existed since the beginning!
+	It showed up on page~37 of the
+	Version~0 |TRIP| manual, but I didn't notice the problem.
+C723\>708. Make optional spaces after \<dimen> like those after \<number>. @448
+C724\>568. Insert \\{every_display} before calling \\{build_page}. @1145
+I725\>648. Report \TeX's capacity on overflow errors in a way that's
+	fully consistent with other statistical reports. @42
+* 17 Jun 1983
+C726. Make all |\tracing| decisions on the basis of $\ge$ versus $<$,
+	not $\ne$ versus~$=$. @581
+# Today I finished the draft of Chapter 27 (the last chapter)!
+# The changes above were released as Version 0.99 on June 19, 1983.
+* 20 Jun 1983
+C727. Set |\catcode`\%=14| in |INITEX|. @232
+C728\>587. Call \\{normal_paragraph} when |\par| occurs in vertical mode. @1094
+# Once again I'm retiring about 8am and awaking about 4pm.
+* 21 Jun 1983
+C729\>558. Don't append an overfull rule solely because of\/ |\hbadness|. @666
+R730. Don't allow the glue-ratio of shrinking to be less than~$-1$. @810,811
+* 22 Jun 1983
+B731\>653. Declare the parameter to \\{print_roman_int} to be of type \\{integer},
+	instead of \\{nonnegative_integer} (found by Debby Clark). @69
+C732\>690. Make the keyword `|by|' optional (suggested by LL). @1236
+* 24 Jun 1983
+I733. Say `|preloaded|' when announcing \\{format_ident}. @1328
+* 25 Jun 1983
+R734. Add extra boxes and
+	glue to the output of alignment. [This thwarts possible attempts
+	at trickery by which system-dependent glue set values
+	computed by |\span| could have gotten into \TeX's registers by
+	things like |\valign| and |\vsplit|. It also has the advantage
+	of perfect accuracy in alignment of vertical rules.] @809
+C735. Make leaders affect the height or width of the enclosing boxes. @656,671
+# Today I'm mainly installing a much-improved format for change files
+	in |WEB| programs (suggested by DRF).
+* 28 Jun 1983
+C736. Permit |\unskip| in vertical mode when we know that it does nothing. @1106
+* 1 Jul 1983
+E737\>700. Avoid redundant boxes when things like `|{\bf A}|' occur in math. @1186
+G738. Add a `|scaled|' feature to |\font| input. @1258
+D739\>700. Remember to correct \\{delta} when an accented box changes. @742
+* 2 Jul 1983
+R740.Introduce \\{bypass_eoln}, to remove anomalous behavior on input files
+	of length~1. (Suggested by DRF after the problem was discovered by LL). @31
+* 4 Jul 1983
+G741. Allow codes like |^^b| as well as |^^B|. @352,355
+G742. Introduce new parameters |\escapechar|, |\endlinechar|, |\defaulthyphenchar|,
+	and |\defaultskewchar|, to make \TeX\ less dependent on the
+	character set. (This affects many modules, since a lot of
+	error messages must be broken up so that they use \\{print_esc}.)
+* 7 Jul 1983
+P743. Use a system-dependent function \\{erstat} when opening or closing
+	files (suggested by DRF). @27
+* 11 Jul 1983
+# The computer is back up after more than 50 hours down time
+	(due to air conditioning failure).
+I744. Show total glue in the output of\/ |\tracingpages|. @985
+R745. Guard against insertion into an hbox. @993
+C746. Legalize the assignment \<tokenvar>=\<tokenvar>. @1227
+I747. Introduce a new parameter |\errhelp|. @1283
+F748\>623. Don't forget to check \\{global_defs} when |\tabskip| is changed. @782
+* 12 Jul 1983
+C749. Allow an |\outer| macro to appear after |\string|, |\noexpand|,
+	and |\meaning| (Todd Allen). @369,471
+C750. Make `|\the|' an expandable control sequence (i.e., move it
+	from the stomach to the throat); this cleans up
+	several annoying glitches. @367
+C751\>620. Allow |\unhbox| and |\unhcopy| in math mode if the box is void. @1110
+* 13 Jul 1983
+# I lectured for four hours at the TUG meeting today after very little sleep!
+* 16 Jul 1983
+# The following were suggested by TUG meeting discussions.
+L752. Round the value of \\{default_rule} more properly: It should be 26215. @463
+Q753\>700. Fix |\mathaccent| again; it's still not right!
+	The final height should be the maximum of
+	the height of accented letter without superscript and
+	the height of unaccented letter with superscript.  @742
+G754. Add a new feature |\newlinechar|. @59
+G755. Allow boxes and rules in discretionaries (suggested by somebody
+	from Hewlett-Packard). @1121
+I756\>X28. Show all token expansions, not just macros,
+	when |\tracingcommands|. @367
+C757. Allow |\char| in a |\hyphenation| list. @935
+G758. Introduce a new feature |\aftergroup|; it can be implemented with
+	\\{save_stack}. @326
+C759. Run the running dimensions to alignment boundaries (suggested
+	by ARK). @806
+* 17 Jul 1983
+R760. Zero out \\{hyf} values at the edges, so that
+	weird pattern data cannot lead to Pascal range checks. @965
+R761\>X190. Decrease the |hc| codes for hyphenation, so that code~127 cannot
+	possibly be matched. @937,962
+C762\>672. Allow whatsits after hyphenatable words. @899
+C763\>604. Represent an italic correction as an explicit kern. @1113
+* 18 Jul 1983
+C764. Allow lowercase letters in file names. @519
+I765. Change the message `|No output file|' to: `|No pages of output|'. @642
+I766. Confirm that a quiet mode is being entered, when error
+	interaction ends with |Q|, |R|, or |S| (suggested by ARK). @86
+# Version 0.999 was finally installed today; a new program listing has
+	been printed.
+# From now on, I plan to keep all section numbers unchanged.
+# I'm done writing Appendix~H; beginning to revise Chapter~20.
+* 25 Jul 1983
+C767\>663. Allow space after `|to|' in the |\read| command (FY). @1215
+# To bed at 1pm today.
+* 27 Jul 1983
+S768\>665. Stack the current type of\/ |\if|; this precaution is necessary
+	in general (FY). @498
+# To bed at 2pm today.
+* 29 Jul 1983
+E769. Avoid putting a control sequence in the hash table
+	when it occurs after |\ifx|. (Requested by Math Reviews people.) @507
+# Finished a version of {\sl The \TeX book\/} lacking only Appendices
+	D, E, and~I, for distribution to interested readers.
+# To bed at 10:30pm, planning to arise regularly at 6am for a change.
+* 31 Jul 1983
+I770\>766. Call \\{update_terminal} when going quiet (HWT). @86
+* 1 Aug 1983
+C771. Don't put an empty line at the end of an |\input| file! (This simplifies
+	the rules and the program, and also gets around a bug that occurred
+	at the end of files with $\\{end_line_char}<0$.) @362
+# The changes above went into Version 0.9999, which was widely distributed.
+* 16 Aug 1983
+B772\>665. Rectify a ridiculous gaffe: I initialized $q$ every time the loop
+	of \\{change_if_limit} was performed! (Found by FY.) @497
+I773\>648. Distinguish `|string|' from `|strings|' when reporting statistics. @1334
+A774. Introduce \\{lx}, to correct a bug in |\xleader| computations
+	(found by FY). @627
+* 20 Aug 1983
+F775. Don't forget to apply |\/| to ligatures. @1113
+# Today I began to read all previous issues of {\sl TUGboat}, in preparation for
+	Appendix~D.
+* 27 Aug 1983
+I776. Add debugging hack number~16, to help catch subtle data structure bugs. @1339
+E777. Remove redundant setting and resetting of \\{name_in_progress}. @531
+S778\>618. Suppress |\input| during a font size spec; otherwise
+	\\{cur_name} is clobbered (found by MDS). @1258
+G779. Introduce new conditionals |\ifhbox| and |\ifvbox|. @505
+* 29 Aug 1983
+D780\>750. Test for an empty list, if emptiness will mess up the data structure.
+	(Found by Todd Allen.) @478
+E781\>624. Use \\{fast_store_new_token} in another place for efficiency. @466
+I782. Say `|has only|' instead of `|has|'. @579
+# These changes yield Version 0.99999, used only at Stanford.
+* 30 Aug 1983
+C783. Make funny blank spaces showable. @298
+* 31 Aug 1983
+C784\>754. Make |\newlinechar| affect \\{print_char}, not just \\{print}. @58
+* 4 Sep 1983
+G785. Add new features |\lastkern|, |\lastpenalty|, |\unkern|, |\unpenalty|.
+	@424,996,1105
+# OK, Appendix D is finished!!
+# The above changes have been installed in Version 0.999999.
+* 17 Sep 1983
+P786\>548. Don't bother making duplicate font identifiers; that
+	was overkill, not really needed. @1258
+# Will this be the historic last change to \TeX?
+* 18 Sep 1983
+I787. Correct a minor inconsistency, `|display|' not `|displayed|'. @211
+* 20 Sep 1983
+C788\>604. Treat the kerns inserted for accents as explicit kerns. @1125
+* 26 Sep 1983
+I789. Change `|log|' to `|transcript|' in several messages. @535,1335
+# The index was finished today; I mailed the entire {\sl \TeX book\/} to
+	Massachusetts for final proofreading before publication.
+* 1 Oct 1983
+D790. Prevent uninitialized trie positions in case of overflow
+	(found by Bernd Schulze). @944
+* 7 Oct 1983
+# Henceforth our weekly `\TeX\ lunch' meetings will be called `\MF\ lunch'.
+# DRF begins to produce {\sl The \TeX book\/} on our APS phototypesetter.
+* 14 Oct 1983
+P791\>633. Ignore spaces at the ends of lines also in |TEX.POOL| (found
+	by DRF). @52
+D792\>610. Initialize the \\{history} variable at \\{start_here} (DRF). @1332
+* 18 Oct 1983
+I793. Extend \\{runaway} to catch runaway text (suggested by FY). @306
+D794. Reset \\{cur_cs} after \\{back_input}, not after scanning the
+	`|=|' (found by FY). @1226
+* 24 Oct 1983
+I795\>638. Change the error recovery for bad delimiters, in accordance with
+	the changed syntax. (Found by Barry Smith.) @1183
+* 9 Nov 1983
+E796. Optimize the code a bit more, based on empirical frequency data gathered
+	during September and October: In \S45, use the fact that the
+	result is almost always true. In \S380, delete `{\bf while}
+	\\{true} {\bf do}' since many compilers implement that badly.
+	Rewrite \S852 to avoid calling \\{badness} in the most common case.
+	@45,380,852
+* 3 Dec 1983
+F797. Don't forget to call |error| after the message has been
+	given (noticed by Gabi Kuper). @500
+# Version 1.0 released today incorporates all of the above.
+* 9 Dec 1983
+# Dinner party with 36 guests to celebrate \TeX's coming of age.
+* 2 Feb 1984
+S798\>786. Reinstall |\font| precautions that I thought were unnecessary.
+	I overlooked many problematic possibilities, like
+	`|{\font\a=x| |\global\a}| |\the\font|'
+	and `|\font\a=x| |\font\b=x| |\let\b=\undefined| |\the\a|', etc.
+	(Found by Mike Urban.) The new remedy involves removal of the
+	\\{font_ident} array and putting the identifiers into a frozen
+	part of the hash table; so there's a sprinkling of corrections
+	in lots of modules. But basically the change is quite conservative,
+	so it shouldn't spawn any new bugs (it says here). @222,267,1257
+* 9 Feb 1984
+S799. Remove the possibility of double interrupt, in a scenario
+	found by Clint Cuzzo. @1031
+* 12 Feb 1984
+Q800. Improve spacing in a formula like |$(A,<)$|. @764
+* 13 Feb 1984
+A801. Avoid a bad {\bf goto}, as diagnosed by Clint Cuzzo and George O'Connor.
+	(Must not go directly to \\{switch}.) @346
+E802. Conserve string pool space by not storing file name in two
+	guises (suggested by DRF). @537
+* 26 Feb 1984
+I803. Make scaled output look cleaner by printing fewer decimals whenever
+	this involves no loss of accuracy. (Suggested by \MF\ development.) @103
+* 2 Mar 1984
+R804. Maintain 17-digit accuracy, not 16; now
+	constants like `|.00000762939453126pt|' will round correctly. @452
+* 16 Mar 1984
+R805. Plug a loophole that permitted recursion in \\{get_next}, by disallowing
+	deletions in \\{check_outer_validity}. @336
+* 24 Mar 1984
+I806. Open the terminal before trying to wake it up, when the program starts bad.
+	@1332
+* 27 Mar 1984
+R807. Check that $k<63$, to avoid the
+	|\patterns{xxx...xxxdxxxdxxx}| anomaly found by Jacques D\'esarm\'enien. @962
+* 11 Apr 1984
+F808. Supply code for the missing case \\{adjust_node} in \\{copy_node_list}. @206
+# Yoicks, how could serious bugs like that have escaped detection?
+* 11 Jun 1984
+D809\>627. Initialize \\{char_base}, etc., for \\{null_font}.
+	(Found by Nick Briggs.) @552
+R810. Clear the \\{buffer} array initially (Briggs). @331
+* 21 Jun 1984
+C811. Look ahead for ligature or kern after a |\chardef|'d item
+	(D\'esarm\'enien). @1038
+* 4 Jul 1984
+R812. Make the quarterword constraint explicit with a
+	new `\\{bad}' case (19). @111
+* 7 Jul 1984
+E813. Optimize \\{firm_up_the_line} slightly,
+	to be consistent with the \MF\ program. @363
+* 8 Jul 1984
+I814. Give additional diagnostics when |\tracingmacros>1|. @323
+# The changes above were incorporated in Version 1.1, released July 9, 1984.
+* 27 Jul 1984
+I815. Say `|see| |the| |transcript| |file|' after handling offline |\show|
+	commands. (Suggested by \MF.) @1298
+* 20 Oct 1984
+I816. Allow `|0|' in response to error prompts. @84
+# Those two changes led to Version 1.2.
+* 25 Nov 1984
+R817. Don't forget to check for \\{null} before looking at subfields
+	of a node. (This was ``dirty Pascal,'' with two quarterword 0's
+	read as a halfword.) @846
+R818. Ditto in another place! @939
+E819. Remove the fixed-at-compile-time
+	partition between lower and upper memory. @116,125,162
+# This major change in memory management
+	completes Version 1.3, which was published in preliminary
+	looseleaf form as `\TeX: The Program'.
+* 20 Dec 1984
+R820. Keep the \\{node_size} field from overflowing if the lower part of memory
+	is too large. @125
+# That was another bug in existence from the beginning!
+* 5 Jan 1985
+I821. Improve the missing-format-file error (DRF). @524
+* 7 Jan 1985
+I822. Update the terminal right away so that the welcoming message will
+	appear as soon as possible (DRF). @61
+* 23 Jan 1985
+I823. Convey more uncertainty in the
+	help message at times of \\{confusion}. @95
+I824\>610. Improve the \\{history} logic in the \\{warning_issued} case. @245
+* 18 Feb 1985
+P825\>810. Stick to standard Pascal: Don't
+	use \\{first} in a {\bf for} loop. [Some procedures ``threaten'' it
+	globally, according to British Standard 6192, section 6.8.3.9.]
+	(Pointed out by CET.) @331
+* 11 Apr 1985
+S826. Prevent nonexistent characters from being output by
+	unusual combinations of ligatures and hyphenation. @915
+* 15 Apr 1985
+L827\>819. Compute memory usage correctly in |INITEX|; the previous number
+	was wrong because of a |WEB| text macro without parentheses (DRF). @164
+* 16 Apr 1985
+E828. Speed up \\{flush_list} by not calling \\{free_avail} (DRF). @123
+* 17 Apr 1985
+A829\>788. Introduce a special kind of kern for accent positioning;
+	it must not disappear after a line break. @837,879,1125
+* 18 Apr 1985
+R830\>755. Prevent |\lastbox| and |\unkern| from removing discretionary replacements.
+	@1081,1105
+# That completes Version 1.4.
+* 26 Apr 1985
+C831. Don't try \\{\TeX_area} if a nonstandard file area has been specified
+	(DRF). @537
+# That was \#401 in \TeX78; I never learn!
+* 30 Apr 1985
+C832\>754. Eliminate the limitation on |\write| length; the reason for it
+	has disappeared (Nancy Tuma). @1370
+* 8 May 1985
+D833\>819. Allocate two words for the head of the \\{active} list (CET). @162
+* 11 May 1985
+I834. Change \\{wterm} to \\{wterm_ln} after a bad beginning (Bill Gropp). @1332
+E835\>806. Don't open the terminal twice (CET). @1332
+* 22 May 1985
+R836. Test for \\{batch_mode} after trying to open the transcript file,
+	not before (DRF). @92
+R837. Be prepared for string pool overflow while reading the command line!
+	(This bug was first found in \MF, when it could occur more easily.) @525
+* 7 Aug 1985
+A838. Fix a bug in |\edef\foo{\iffalse\fi\the\toks0}|: \TeX\ should stay in the
+	loop when expanding non-|\the|. (Found by Dan Brotsky.) @478
+# The above changes were incorporated in Version 1.5.
+* 27 Nov 1985
+C839\>764. Make `|plain|' a lowercase name, for consistency with the manual. @521
+I840\>669. Wake up the terminal for |\show| commands. @1294,1297
+# The above changes were incorporated in Version 2.0, which was published
+	as Volume~B of the {\sl Computers \& Typesetting\/} series.
+* 15 Dec 1986
+I841. Punctuate the Poirot help message more carefully. @1283
+* 28 Jan 1987
+R842. Make sure that \\{max_in_open} doesn't exceed 127 (DRF). @14
+D843\>680. Don't allow a |\kern| to be clobbered at the end of a pre-break list
+	when a discretionary break is taken. (A missing `{\bf else}' was the
+	source of the error, diagnosed incorrectly before.) @881
+D844. Take account of discarded nodes when computing the background width
+	after a discretionary. @840
+# That was the first really serious bug detected for more than 17 months! I found it
+	while experimenting with right-to-left extensions.
+# Version 2.1 was released on January 26, 1987.
+* 5 Feb 1987
+E845. Remove cases in \\{shorthand_def} that cannot occur (found by Pat Monardo). @1224
+* 14 Apr 1987
+R846. Improve robustness of data structure display
+	when debugging (Ronaldo Am\'a). @174,182
+* 21 Apr 1987
+E847. Make the storage allocation algorithm more elegant and efficient. @127
+* 22 Apr 1987
+A848\>742. Calculate the empty-line condition properly when \\{end_line_char} is
+	absent. @360
+# The previous three changes were found while I was teaching a class based
+	on Volume~B; they led to Version 2.2.
+* 28 Apr 1987
+E849. Avoid closing a file when \TeX\ knows that it isn't open (JS). @560
+* 3 Aug 1987
+S850. Clean up unfinished output if it's necessary to
+	\\{jump_out} (Klaus Guntermann). @642
+# That makes Version 2.3; subsequent version numbers won't be logged here.
+* 19 Aug 1987
+A851. Indent rules properly in cases like\hfil\break
+	|\hangindent=1pt$$\halign{...\cr\noalign{\hrule}}$$|. @806
+* 20 Aug 1987
+S852. Introduce \\{co_backup} because of cases like
+	|\hskip 0pt plus 1fil\ifdim| (Alan Guth). @366
+* 9 Nov 1987
+S853. Change the calculation for number of leader boxes, so that
+	it won't be too sensitive to roundoff error near exact multiples
+	(M. F. Bridgland). @626
+* 17 Nov 1987
+A854. Replace my stupid algorithm
+	for fixed-point multiplication of negatives (WGS). @572
+* 12 Dec 1987
+B855. Fix a typo in the initialization of hyphenation tables  (PB). @952
+# That error was almost completely harmless, thus undetectable,
+	except if some |\lccode| is~1 and no |\patterns| are given.
+* 23 Dec 1987
+S856\>564. Be more cautious when ``relaxing'' a previously undefined |\csname|;
+	you might be inside a group (CET). @372
+* 20 Apr 1988
+S857. Make sure \\{temp_head} is well-formed whenever it can be
+	printed in a ``runaway'' message: Consider constructions like
+	|\outer\def\a0{}\a\a| (Silvio Levy). @391
+* 24 Apr 1988
+S858\>618. Avoid conflicting use of the string pool in constructions like
+	|\def\\#1{}\input a\\\z| (Robert Messer). @260
+* 10 May 1988
+R859. Amend the |\patterns| data structure when $\\{trie_min}=0$
+	(PB). @951,953
+* 25 May 1988
+R860. Guarantee that \\{trie_pointer} cannot be out of range. @923
+S861\>618. Avoid additional bugs like \#858 in constructions
+	like |\input a\romannumeral1|, etc. @464,465,470
+R862\>618. Prevent similar string pool confusion that could occur
+	during the processing of |**\input\romannumeral6|. @525
+* 19 Jun 1988
+S863\>819. Prevent a negative dividend from rounding upward,
+	causing a loop (CET). @126
+E864\>819. Adopt a smoother allocation strategy when
+	memory is nearly gone (CET). @126
+* 20 Jun 1988
+D865\>852. Initialize \\{cur_order}, now that it's being backed up
+	(Tsunetoshi Hayashi). @439
+* 6 Nov 1988
+S866\>612. Disable \\{fatal_error} in \\{prompt_input}, so that
+	\\{open_log_file} can use it safely (Tim Morgan). @71
+S867\>836. Force terminal output whenever \\{open_log_file} fails. @535
+* 14 Dec 1988
+P868\>866. Restore \\{fatal_error} in \\{prompt_input}, but don't
+	let it be unsafe for \\{open_log_file}. @92,534
+* 23 Jan 1989
+D869. Give $q$ a legal value when recovering from ``infinite shrinkage''
+	error. @976,1004
+* 17 Feb 1989
+D870\>758. Avoid spurious error message for |\aftergroup\relax\dump| by avoiding
+	inaccessible |\aftergroup| tokens (FM and Rainer Sch\"opf). @280
+* 20 Mar 1989
+R871. Don't refer to \\{link}(\\{null}) even when it ``can't happen''
+	(PB). @791
+* 7 Jun 1989
+S872. Avoid confusion from |$$\begingroup\halign{#\cr}$$| (FM). @1130
+* 20 Jun 1989
+S873. Put fraction digits into dynamic memory, not the global \\{dig} array,
+	because of constructions like |.5\ifdim.6| (FM). @452
+* 17 Jul 1989
+S874. Prevent embarrassing attempts to report errors before the string
+	mechanism has been fully initialized, for example when the
+	command line exceeds the buffer size (WGS). @31
+* 16 Aug 1989
+M875. Allow integer products to be 31 bits long (FM). @105
+* 31 Aug 1989
+C876\>441. Increase the number of tokens shown by \\{token_show}
+	(J. Lavagnino). @295
+S877. Avoid confusion from |$$\begingroup\eqno$$| (FM). @1140
+# The recent TUG meeting turned out to be an extend-\TeX-for-the-nineties
+	party! I agreed that some extensions for non-English languages
+	ought to be made while I still knew how to do them. (In other words,
+	I broke my firm commitment to keeping \TeX\ completely stable;
+	but in this case nobody objected.) The following eleven changes
+	were coded during the month of September.
+* 30 Sep 1989
+G878. Install major change allowing general 8-bit code input. @38,352
+G879. Install major change allowing multiple hyphenation tables
+	(M. Ferguson). @923
+G880. Introduce new parameters |\lefthyphenmin| and |\righthyphenmin|. @923
+G881. Introduce major new ligature capabilities including implicit
+	boundary characters. @908,1037
+G882. Install new |\inputlineno| feature suggested by MDS. @424
+G883. Install new |\holdinginserts| feature suggested by FM. @1014
+G884. Install new |\badness| feature. @424,664
+G885. Install new |\emergencystretch| feature. @863
+G886. Install new |\errorcontextlines| feature suggested by FM. @311
+S887. Recover from anomaly when hyphenation |char_warning| clobbers
+	|old_setting|. @863
+P888. Make it easier to change the format extension (Don Hosek). @520,1328
+* 16 Oct 1989
+R889. Avoid range check in null font with |bc=256| (PB). @565
+* 22 Nov 1989
+S890\>856. Prevent \\{save_stack} conflicts in
+	|{\hbox\expandafter{\csname\endcsname}}| and\kern-3pt\break
+	similar constructions (WGS). @645,1117
+S891\>858. System-dependent parts of file names must be addressed relatively,
+	not absolutely (FM and Rainer Sch\"opf). @516,517
+* 3 Dec 1989
+G892\>880. Allow different hyphenmins in the same paragraph (M. Ferguson). @1376
+S893. Distinguish |\par| from characters on |\if| tests. (MVL). @334
+S894\>378. Alignments need to be more robust against malicious
+	attacks (MVL). @782
+C895. Don't let kerns in discretionaries disappear at breaks (MVL). @869
+Q896\>881. Make the new hyphenation reconstruction procedure less cautious,
+	so that it doesn't lose hyphens found by the old method. @914
+* 11 Dec 1989
+D897\>879. Make an undumped trie dumpable again (PB). @1325
+* 18 Dec 1989
+G898\>588. Allow access to page totals in |\output| routines
+	(FM and Chris Rowley). @421
+* 22 Jan 1990
+R899\>611. Recognize more cases of unbalanced |\output| (CET). @1026
+* 29 Jan 1990
+S900\>758. Make |\aftergroup| work properly after |\eqno| (Michael Downes).
+	@1194
+* 1 Feb 1990
+S901\>878. Fix one more case of \\{end_line_char_inactive} (WGS). @360
+* 22 Feb 1990
+R902. Don't lose the last active node when total demerits are very high (FM).
+	@836,854
+* 13 Mar 1990
+D903. Doublecheck math fonts after making equation number (MVL). @1194
+D904. Don't forget to rule out charnodes before testing \\{type} (MVL).
+	@805,1202
+* 23 Mar 1990
+F905\>881. Don't change the font of punctuation preceding a hyphenated word
+	(Scott C. Allendorf). @903
+I906. Balance the parentheses shown on the terminal during normal runs. @1335
+E907. Optimize |\ifx\p\q| after |\let\p=\q| (MVL). @508
+S908. Treat migration properly in displays (MVL). @1199,1205
+# We're now up to Version 3.0; I sincerely hope all bugs have been found.
+* 11 May 1990
+F909\>881. Initialize |\nullfont| ligature parameters (Lance Carnes). @552
+* 22 July 1990
+S910\>579. Treat |\prevgraf| as zero within |\write| (Bogus\l aw Jackowski).
+	@422
+* 26 July 1990
+S911. Report `|l.1|' when first line of file overflows buffer
+	(George Russell). @538
+* 5 December 1990
+S912\>878. Translate unprintable characters in font identifiers (WGS). @63
+* 28 December 1990
+R913. Avoid range check when there are 65536 or more pages (Eberhard Mattes).
+	@642
+* 20 September 1991
+I914\>878. Improve error message for |\mathchar| out of range. @436
+S915\>878. Retain unprintable internal strings in 8-bit form (FM). @59
+S916\>881. Retain right punctuation context for ligature reconstruction
+	(problem found by Brian Hamilton Kelly). @903
+* 10 January 1992
+S917\>881. Also avoid producing a double kern at boundary (CET). @897
+S918. Disallow |\setbox| where it doesn't work (Robert Hunt). @1241,1270
+S919. Robustify |\mskip| and |\mkern| in presence of negative quad (WGS).
+	@716,717
+S920\>679. Defend against `|}{|' in |\read| (Michael Downes). @483
+E921\>798. Save string memory if font occurs repeatedly (Bogus\l aw Jackowski).
+	@1260
+S922\>784. Don't let |\newlinechar| interrupt unprintable expansion (Bernd
+	Raichle). @59,60
+* 7 February 1992
+D923\>881. Restore |cur_l| properly when boundary character doesn't exist
+	(Mattes and Raichle). @1036
+* 17 July 1992
+C924\>892. Use current language at beginning of horizontal mode (Rainer
+	Sch\"opf and CET). @1091,1200
+* 17 December 1992
+R925\>879. Avoid (harmless) range errors (Philip Taylor and CET). @934,960
+* 25 February 1993
+C926\>881. Protect kerns inserted by boundary characters (William Baxter).
+	@837,866
+S927\>917. Don't let boundary kern disappear after hyphenation. @897
+* 26 June 1993
+R928\>668. Avoid potential future bug (Peter Breitenlohner). @628,637
+* 17 December 1993
+S929\>881. Boundary character representation shouldn't depend on the font
+	memory size (Berthold Horn). @549,1323
+* 10 March 1994
+R930. Huge font parameter number may exceed array bound (CET). @549
+* 4 September 1994
+F931\>926. Math kerns are explicit (Walter Carlip). @717
+R932. Avoid overflow on huge real-to-integer conversion. @625,634
+* 19 March 1995
+R933. Avoid spurious reference counts in format files (PB). @1335
+* 23 November 1998
+R934. Make sure that \TeX\ is certifiably Y2K-safe. @1328
+* 12 July 1999
+A935\>255. |\xleaders| often drops the final box (Hiroshi Nakashima). @627,636
+* 30 August 2001
+R936. Don't allow a million unbalanced braces followed by |\cr|
+	outside of any alignment (Ralf Roth). @789
+R937. Don't allow end-template except at end of template (Roth). @325,1131
+* 30 September 2002
+Q938. Improve rounding of glue during output (M. F. Bridgland). @625,634
+* 18 March 2008
+F939. Forgot to goto the proper error recovery (DRF). @395
+E940. Avoid a case of dirty Pascal and speed up inner loop. @1035
+R941. Forget reference to \\{last_glue} in format file (DRF). @1335
+R942. Glue reference not updated after overflow error (DRF). @1236
+B943. Muglue in |\leaders| had wrong units; now disallowed (DRF). @1078
+E944. Speedup of ligatures and kerns at end of a word (DRF). @1039
+R945. Another sanity check of TFM files for security (DRF). @565
+I946. Give better size data for unmagnified insertions. @986
+* 6 January 2014
+C947. Space after |\csname\endcsname| to match other spaces. (Oleg Bulatov) @262
+* 15 January 2021
+I948. Don't pause on errors when tracing paragraphs (Udo Wermuth). @826
+S949. Don't try to interact when in |\batchmode| (Xiaosa Zhang). @83
+S950. Don't try to edit when no file is active (Xiaosa Zhang). @84
+R951. Take date and time sometimes from system, not user (Udo Wermuth). @241,536
+B952. Don't allow implicit left brace after |#| (Udo Wermuth). @476
+R953. After nine parameters, must delete offending tokens (Bruno Le Floch). @476
+D954. Garbage visible in buffer after file ends prematurely (DRF). @486
+R955. Force nonexistent characters to have null specs (DRF). @722
+C956. Don't mark fraction noads as temporarily Inner (DRF). @761
+Q957. Reset |\newlinechar| before logging the stats (Udo Wermuth). @1333,1335
+\relax
+\bye
+
+Up to a point it is better to let the snags [bugs] be there
+than to spend such time in design that there are none
+(how many decades would this course take?).
+-- A M Turing
+   Proposals for Development in the Mathematics Division
+     of an Automatic Computing Engine (ACE)
+   Report E882, Executive Committee, National Physical Laboratory (NPL)
+   1945; reprinted in April 1972 as NPL report Com Sci 57
+   page 18
+   quoted by Carpenter and Doran in The Computer Journal 20 (1977), 273.
+
+DRF David Fuchs
+HWT Howard Trickey
+FY  Frank Yellin
+LL  Leslie Lamport
+JS  Jim Sterken
+ARK Arthur Keller
+CET Chris Thompson
+FM  Frank Mittelbach (added subsequent to publication of paper)
+PB  Peter Breitenlohner (ditto)
+WGS Wayne G. Sullivan (ditto)
+MVL Marc van Leeuwen (ditto)
+MDS Michael D. Spivak (ditto)
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/logmac.tex b/Master/texmf-dist/doc/generic/knuth-errata/logmac.tex
new file mode 100644
index 00000000000..8719efc497d
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/logmac.tex
@@ -0,0 +1,107 @@
+% macros for the appendix to "Errors of TeX" paper
+\input manmac
+\voffset=-.3in
+\catcode`\^=7 % disable the indexing stuff
+\font\sltt=cmsltt9
+\font\logosl=logosl9
+\ninepoint
+\vsize=48pc \pageheight=\vsize
+\hsize=33.5pc
+
+\def\\{\bgroup\catcode`_=\active\identifier}
+{\catcode`_=\active \global\let_=\_}
+\def\identifier#1{\hbox{\it#1\/\kern.05em}\egroup} % italic type for identifiers
+
+\newdimen\codesize \setbox0=\hbox{\enspace M} \codesize=\wd0
+\setbox0=\hbox{\thinspace\S1111\kern\codesize} \rightskip=\wd0
+\newdimen\itemnosize \setbox0=\hbox{\bf999} \itemnosize=\wd0
+\setbox0=\hbox{$999\mapsto{}$\kern\itemnosize\enspace} \parindent=\wd0
+\newdimen\datemar \setbox0=\hbox{\bf 15 Mar 1977}
+\datemar=\hsize \advance\datemar-\wd0 \divide\datemar2
+\newdimen\hangamount \hangamount=\parindent \advance\hangamount 1em
+\everypar{\global\hangindent=\hangamount}
+\parfillskip=-\rightskip
+\finalhyphendemerits=0
+\interlinepenalty=100
+\smallskipamount=3pt plus 2pt
+\def\smallbreak{\fin\penalty-50\smallskip}
+
+\newbox\predec % for predecessor "mapsto" info
+\newbox\code   % for the code letter
+\newbox\texsec % for TeX section numbers
+\newbox\cbox   % the symbol used on commentlines
+\newbox\dbox   % empty box used after datelines
+\setbox\dbox=\hbox to\datemar{}
+\setbox\cbox=\hbox to\itemnosize{\hfil$\bullet$}
+
+\newif\ifnothing \newif\ifnobreak
+\def\fin{\ifnothing\nothingfalse\else\endgroup
+ \unskip\nobreak\hfil\penalty500\enspace\null\nobreak\hfil\box\texsec
+ \box\code\endgraf\ifnobreak\nobreakfalse\nobreak\fi\fi}
+
+\catcode`\	=12 % tabs are ordinary characters
+\catcode`@=\active  % @ signs denote a TeX section reference
+{\obeylines \gdef@#1
+ {\global\setbox\texsec=\hbox{\S$#1$}\lookahead}}
+\chardef\@=`\@
+{\catcode`X=\active \gdef X{\X}}
+\def\X{{\eightbf X}}
+\def\lightX{\hbox{\eightrm X}}
+\def\>#1\relax{\global\setbox\predec=\hbox{\let\X=\lightX
+  $#1\mapsto{}$}} % previous bug ref
+
+\def\checkvalid#1{\expandafter\ifx\csname#1!\endcsname\okay\else\invalidcode\fi}
+\def\okay{\okay}
+\def\makevalid#1{\expandafter\let\csname#1!\endcsname=\okay}
+\makevalid A % algorithm
+\makevalid B % blunder
+\makevalid C % cleanup
+\makevalid D % data structure
+\makevalid E % efficiency
+\makevalid F % forgotten case
+\makevalid G % generalization
+\makevalid I % interaction
+\makevalid L % language
+\makevalid M % mismatch
+\makevalid P % program organization
+\makevalid Q % quality
+\makevalid R % robustness
+\makevalid S % surprise
+\makevalid T % typo
+
+\def\lookahead{\futurelet\next\looky} % we'll do this at end of every line
+\def\looky{\if\next	\let\cont\continuationline % tab mark
+  \else\if\next*\let\cont\dateline % asterisk
+  \else\if\next##\let\cont\commentline % sharp sign
+  \else\if\next\relax\let\cont\endit % \relax (gets us out)
+  \else\let\cont\dataline\fi\fi\fi\fi\cont} % otherwise should be a code letter
+\def\continuationline	{ } % insert space if a tab mark starts the next line
+\def\dateline* {\smallbreak\begingroup\bf\hfill\nobreaktrue
+  \global\setbox\code=\copy\dbox}
+\def\dataline#1{\fin\checkvalid#1%
+  \global\setbox\code=\hbox to\codesize{\enspace
+   \hskip0pt plus 3fil\rm#1\hskip0pt plus1fil}%
+  \begingroup\rm\catcode`X=\active\itemnumber}
+\def\itemnumber#1.{\catcode`X=11\setbox0=\hbox to\itemnosize{\bf\hss#1\relax}%
+  \setbox2=\hbox{\bf#1\relax}\ifdim\wd2>\wd0 \setbox0=\box2 \fi
+  \textindent{\hfil\box\predec\box0}}
+\def\commentline{\fin\afterassignment\begincomment\let\next}
+\def\begincomment{\begingroup\let\tt=\sltt
+  \let\MF=\slMF\sl\textindent{\hfil\copy\cbox}}
+
+\def\leftheadline{\hbox to \hsize{%
+    \vbox to 10pt{}% strut to position the baseline
+    {\tenrm\folio\kern1pc}% folio to left of text
+    \hfil\eightrm D. \ E. \ KNUTH\hfil% running head 
+    }}
+\def\rightheadline{\hbox to \hsize{%
+    \vbox to 10pt{}% strut to position the baseline
+    \hfil\eightrm THE \ ERRORS \ OF \ \TeX\hfil% running head 
+    {\kern1pc\tenrm\folio}% folio to right of text
+    }}
+
+\def\O#1{\hbox{\rm\char'23\kern-.2em\it#1\/\kern.05em}} % octal constant
+\def\slMF{{\logosl META}\-{\logosl FONT}}
+
+\def\endit{\fin\catcode`\^^M=5\let\par=\endgraf}
+\let\par=\lookahead \obeylines \nothingtrue
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/mf84.bug b/Master/texmf-dist/doc/generic/knuth-errata/mf84.bug
new file mode 100644
index 00000000000..c6349b896da
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/mf84.bug
@@ -0,0 +1,2443 @@
+This file has been updated periodically ever since METAFONT84 was born.
+What you are about to read is "authentic source material" from the
+early days before the program converged. Module numbers on the first
+entries may bear little relation to those in Volume D.
+
+Entries are in chronological order; thus the most recent news appears
+at the bottom of the file.
+
+-------------------------------------------------------------------------------
+
+(rough list of all bugs found in MF after it passed syntax check)
+Starting with Version -100.0: [Mar 27, first run, about 00:30]
+1. fix_date_and_time was badly patched in INIMF.
+2. cur_tok function forgot "cur_tok:=p" at the end; PASCAL doesn't catch that.
+3. "multiletter control sequences" msgs should say "symbolic tokens".
+Version -99.0: [still Mar 27, done while waiting for WEAVE/TeX output]
+4. do_statement should initialize cur_type:=vacuous.
+5. find_variable has misplaced p:=equiv(p).
+6. one-character primitives shouldn't decrease str_ptr.
+7. clear_symbol had "q" at end where I meant to say "p".
+8. help message for extra token flushing improved.
+9. "buffer[k]" should be "buffer[j]" for 1-character id_lookup.
+10. def_delims forgot to get_next afterwards.
+11. type_command at beginning of statement wasn't diverted.
+12. menu always came out after help message.
+13. forgot to return after getting num/str token from token list.
+Version -98.0: [March 28]
+14. scan_declared_variable flushes too much.
+15. ordered pairs: one level of indirection was forgotten.
+16. type declarations must add "unknown" bit.
+17. semicolon+ added to do_statement cases.
+18. base_ident should get max_str_ref.
+19. "internal[...]" missing in date for base_ident.
+20. do_binary(p,c) should be do_binary(p,d) after continue_path
+21. in scan_def after get_clear_symbol I need to get_next.
+22. get_next needed at end of scan_def.
+23. get_next needed at end of mode_command processing.
+24. randomseed missing error typo: `;' for `:='.
+25. print_nl("") at beginning of show.
+26. refcounts on macro calls were incremented twice.
+27. forgot to advance loc after getting num/str token from token list.
+28. "/" has the wrong command code.
+29. get_x_next needed after, e.g., "1/2" in scan_primary.
+30. take_fraction should be make_fraction in call of frac_mult.
+31. v:=dep_list(v) forgotten in dep+dep branch of add_or_subtract.
+32. q:=link(q) etc misplaced and omitted in p_plus_fq and p_plus_q.
+33. dep_finish recycled a dependency list twice.
+34. call of dep_finish should use null not cur_exp.
+35. decided that "3 3" shouldn't equal 9.
+[also put in new code for the addto command]
+Version -97.0: [March 29]
+36. forget to set q:=qq in scan_expression.
+37. first line of print_path: forgot print_ln.
+38. typo in set_controls: right_y should be left_y.
+39. toss_knot_list forgot that it has a circular list to toss.
+40. print_exp shows big nodes backwards.
+41. angle brackets didn't look good in print_exp; took them out.
+42. left_brace must be between min_tertiary and max_tertiary.
+43. prev_dep should point back to tail, not head, of previous list.
+  (that error was in encapsulate and <Copy the big node>)
+44. nonlinear_eq should leave node p vacant, sometimes.
+45. conditional routine forgot that get_boolean starts with get_x_next.
+46. forgot get_x_next in processing of else.
+47. str_ref not initialized by make_string.
+48. param_start not initialized properly.
+49. "%EXPR" didn't look good in token list.
+50. "{loop}" not necessary in forever loops; there's already enough.
+51. macro name didn't come out right when tracing macros.
+52. macro parameters weren't shown when tracing macros.
+53. quote marks missing when displaying strings.
+54. parameter names on macro call trace should look nicer.
+55. statement beginning with bad token: error message needed.
+56. `->' desired in context lines of macro.
+57. forgot q:=loop_list_loc(s) in begin_iteration.
+[also put in new code for shipout]
+Version -96.0: [March 30]
+58. forgot loop_type(s):=null in begin_iteration.
+59. forgot value(p):=null after type(p):=type(pp) in find_variable.
+60. forgot to delete_pen_ref after filling a contour.
+61. check that it's a cycle before calling make_spec.
+62. "if tracing_stats>0" should be "if internal[tracing_stats]>0"!
+63. forgot get_next after showdependencies.
+64. forgot link(r):=p at end of dependency list addition.
+65. extra `get_x_next' in <Scan a direction...>.
+66. typos in last half of <Remove open types...>: mind the p's and q's.
+67. take_fraction should be make_fraction in simple case of two givens.
+68. in print_exp of unknown type, stop if v=null.
+69. showtoken forgot to stop; also should be consistent with TeX.
+70. "continue" label needed in error routine, after all.
+71. id_lookup should treat length-one identifiers by simpler method.
+  (in particular, this allows it to find unprintable ones!)
+72. need psi[n+1]:=psi[1] in cyclic case of make_choices.
+73. tension/controls take primaries as arguments, not expressions.
+74. print_spec didn't initialize octant.
+75. print_spec: break lines into two, since they are quite long.
+76. smooth_moves not called in fill_spec.
+77. typo < for > in edge_prep.
+78. edge tracing misses half the corners, and forgot to set trace_y.
+79. edge_prep needs extra logic when rover=head.
+80. make_good should compute cur_d based on good values, not original values;
+  but we sometimes need the other alternative too.
+81. valid_sum: the test was backwards.
+82. print_weight blunder: ho(q) should be ho(info(q)).
+83. forgot init_gf in shipout.
+84. typo in <Finish the GF file>: if total_chars<>1 then print("s").
+85. initializations of ww, prev_w, and m were forgotten in ship_out.
+86. typos in initialization of prev_m and gf_min_x.
+87. forgot to update prev_n in ship_out.
+88. relax becomes "expandable".
+89. internal[x]>1 should be internal[x]>unity!
+90. forgot to restore normal scanner_status in pass_text.
+91. (end occurred when if...) was inevitable.
+[also put in new code for openwindow, display]
+Version -95.0: [April 1]
+92. forgot to unscale the window numbers in that new code.
+93. had w<0 test instead of w<=0 in <Record a possible transition...>.
+94. prev_w:=w should be done in all cases of <Record a possible...>.
+95. forgot get_x_next after scanning `1/2'.
+96. in do_assignment, after recycle_value(p) I need to set type(p):=something.
+97. omit `.' after the equivalent in showtoken.
+98. in <Copy the big node p>, I said "until q=p"; I meant "until q=value(p)".
+99. print_macro_name said "info(link(a))"; meant "text(info(info(link(a))))".
+100. forgot get_x_next after macro_call in scan_primary.
+101. scan_primary installed dependent components badly (data structure error).
+102. new_structure failed in case of generic_subscript (data structure error).
+103. param_type case of print_cmd_mod had bad if/else nesting (language error).
+104. null_path forgot to return a value (language error).
+105. p_with_x_becoming_q had typos (q and f for x).
+106. <Copy the big node...> should end with cur_exp:=t, not r.
+107. subscripted definitions: out of sync; scan_primary loop needs revision.
+108. secondarydef went through scan_def instead of make_op_def.
+109. make_op_def forgot the final get_next.
+110. make_op_def also forgot to insert the general_macro preface.
+111. showvar shows too much of macro variables.
+Version -94.0: [April 4]
+112. single_dependency needs to take account of the scale factor.
+113. add_or_subtract starts out with wrong v value. [bug 31 was fixed wrong]
+114. print_exp needs a case for t=independent.
+115. also numeric_type, and case v=null of pair_type, transform_type.
+116. end_token_list thought identity_macro and insertions had ref counts.
+117. disp_var should display also in case of generic subscripts.
+118. find_var should put value(pp):=null when it sets type(pp):=numeric_type.
+119. yet another problem in <Copy the big...>: copy_dep_list(dep_list(q)).
+120. scan_primary should flush_node_list(q) before make_exp_copy(p).
+121. make_scaled arguments reversed in p_over_v.
+[also added code for new internals: smoothing, autorounding]
+[also added code for showstats]
+Version -90.0: [April 5]
+122. Should check range of variables when they become known.
+123. <Exclaim about...> should include begin...end (WEB language error).
+124. forever should be followed by a colon.
+125. dangling else problem in make_eq: "abc"="abc" considered false.
+126. showstats, showtoken should read the semicolon before stopping.
+127. print_variable_name balked at, e.g., xpart of a capsule.
+Version -89.0: [April 6]
+128. after &foo, shouldn't assume there's an input file present.
+129. forever forgot get_next.
+130. pair=path and path=pair should coerce the pair to be a path.
+131. similarly in the operand to `addto'.
+[added new code for cull command]
+[minor revision of internal quantities; e.g., labeling is out, fontmaking is in]
+Version -88.0: [April 7]
+132. "string" operator is renamed "str".
+133. min/max coordinates added to boc command.
+134. labeling_command removed; it will be implemented in macros.
+135. info(p) should be attr_loc(p) in flush_variable.
+136. make_spec didn't realize the need for xh and yh.
+137. gf_new_row parameters had sign reversed.
+138. the "numeric" case was left out of recycle_value.
+[added new code for special/numspecial]
+Version -87.0: [April 13]
+139. q:=qq should apply also after <Splice...>, in scan_expr.
+140. param_size: better defined than a constant.
+141. surprise: back_input fails when cur_cmd=expr_arg, as it changes limit.
+142. <Subdivide...second time wrt x'-y'> forgot to change right_type(r).
+143. show <path> shows the whole path.
+144. expr like 0..1 leads to <Determine the path join...> with q undefined.
+145. typos in <Decide...clockwise>, clobbered dx2 and used right_type(p) twice.
+146. need to adjust expr_arg when macro is inside a macro!
+147. expr_arg forbidden to be in a text argument.
+148. frozen_relax added to prevent premature termination.
+[I took out the code used for debugging the screen interface]
+[added "cycle", a unary operator taking path to boolean]
+[added the code for concatenation and for str and for xpart..yypart]
+Version -86.0: [April 25]
+149. not_scolded_yet was never set false after scolding.
+150. Missing "q:=s" at the end of <Make variable q known>.
+151. In @<Worry...@>, add get_next after back_error.
+152. New xpart routine didn't recycle other components of the big node.
+[added the "hard_times" case of multiplication]
+[added the complete set of boolean expressions]
+[added the eight transformations, applied to three kinds of expressions]
+[added the save command]
+[added the interim command]
+[added the let command]
+[added the pen operations]
+153. Incomplete help message on "Not a variable".
+154. forgot begin...end in the last section of materialize_pen.
+155. blunder <Insert a new line...>: length(p,s,q) should be length(s,q,r).
+156. <Construct the offset...>: forgot begin...end here too.
+157. "(newly created)" shd be " (newly created)".
+158. path_trans: forgot to unstash the capsule p.
+159. set_up_trans: transform_type should be transformed_by, in one place.
+160. <Install sines...>: had p instead of q, in several places.
+161. edges_trans: an edges variable isn't in a capsule.
+Version -85.0: [May 2]
+162. begingroup ... endgroup should be allowed as compound statement.
+163. pausing shouldn't clobber "showit". (WAITS version only)
+164. Improved help message for isolated expressions.
+165. Bad error recovery after "Not a variable" in showvar.
+166. Typo in clear_symbol: name_type(p) instead of name_type(q).
+167. "%" and ";" to be left out of file names being input.
+168. dep_finish used v for two purposes; wrong declared type.
+169. autorounding 2 suppresses correction when the derivative isn't critical.
+170. tab characters should be changed to spaces on input. (WAITS version)
+171. harmful goto: Forgot to |return| after path_trans and edge_trans.
+[added ord, hex, oct, length, char, decimal, and jobname]
+Version -80.0: [May 4]
+172. showvar still screwed up.
+173. don't clobber screen for prompt_input (WAITS only).
+174. length of non-cyclic path is one too high.
+175. <Evoke an error message...> evoked the wrong message.
+176. better error message needed on `Equation cannot be performed'.
+177. ">> " inserted before expression displays.
+178. <Finish linking...> should dup_offset also when n=0.
+179. pencircle was a factor of 2 too big.
+180. cosine of 180 should be -1 exactly.
+181. ord "" should be -1.
+182. shipout should allow expressions as well as variables.
+183. "mod outer_tag" needed in various tests on eq_type.
+184. merge_edges forgot to adjust for changes in m_offsets.
+185. typo, ww for w in print_pen.
+186. typo, "outer" for "errhelp" in print_cmd_mod (message case).
+[added "also"]
+[added "message", "errmessage", "errhelp"]
+[added "outer", "inner"]
+[added "readterminal", "readstring"]
+Version -79.0: [May 6]
+187. read_toks forgot to include the general_macro token.
+188. offset_prep should treat n=0 like n=1.
+189. cusp transitions (from change 169) must be suppressed in envelope case.
+190. <Record a line segment...> shouldn't change xp or yp.
+191. <Find the initial slope...> was used too late.
+192. <Find the index...> had a redundant test (a relic of old code).
+193. <Compute test coeff...> wastefully made the same fraction three times.
+194. doublepath <cycle> should split the cycle.
+195. `if k=0' in fin_offset_prep should have been `if k=1'.
+196. `done:' misplaced in <Make the envelope moves...>.
+197. also move[move_ptr] should be initialized to 1 there, not 0.
+198. skew is used with p=q in fill_envelope.
+199. it's no use tracing subdivision for offsets, since everything is skewed.
+200. in <Record a line...>, round_unscaled should be floor_unscaled.
+201. unskewing: wrong formula (x was .5 too large).
+202. elliptical pens: better correction for the case gamma<=abs(alpha).
+203. dual env_move was updated badly, in both <Transfer...> and <Record...>.
+204. dual env_move to move: subscripts were off by 1.
+205. <Insert...dually...> should set ww:=knil(link(h)), not link(h).
+[added ++]
+Version -70.0: [May 9]
+206. suppressed cusp rounding in envelope case too.
+207. `show' should use `>> ' when it shows an expression.
+208. streamlined the test for bad lambda and mu in |skew|.
+209. after linear_eq, must check if type(cur_exp)=known.
+210. print_spec surprise: contours might never travel toward the first octant!
+211. t0,t1,t2 sign was reversed in <Complete the offset splitting...>.
+Version -69.0: [May 10]
+212. "showvar" changed to "showvariable".
+213. typo: r for r_delim in <Scan a text parameter...>.
+214. "newinternal" feature added.
+215. <Record a line...dually...> needs to update envmove at end of loop.
+216. smooth_moves shouldn't affect the extreme points.
+217. floor(unity*(n-1)/n) is unity when n is large; need to be more careful.
+218. major improvements to rounding, based on new theory of (x+eps,y+eps^2).
+219. pen offsets made symmetrical about the origin.
+220. p:=half(p+q) overflow problem in take_fraction, take_scaled.
+221. cull_edges now updates the max/min values too.
+222. make_spec needs to be more bullet-proof to rounding errors; added `dest's.
+223. xmult/ymult/zmult changed to xscaled/yscaled/zscaled.
+224. elliptical pens improved by temporarily allowing zero-length lines.
+[added edge transposition algorithm]
+Version -67.0: [May 17]
+225. copy can encounter a vacuous expression, e.g. in a parameter.
+226. xy_swap_edges mustn't change w when inserting a large weight.
+227. in #222, had typo pp for r in <split ... second time ... x'-y'>.
+228. in #222, incorrectly assumed local max = global max of cubic.
+Version -66.0: [May 19]
+229. bad_binary(c,p) should have been bad_binary(p,c).
+230. enabled comparison of unknown strings.
+231. fixed ring_delete to avoid unexpected scolding.
+232. should store character width info even when proofing<0.
+[added all the TFM commands and output routines]
+[added the `substring' operation]
+[added `point', `precontrol', `postcontrol'; deleted `direction']
+Version -65.0: [May 24]
+233. Change error message `(t)point(u)' to `point(t)of(u)'.
+234. newinternal to allow a list of tokens.
+235. In <Feed...>, should check for overflow before begin_token_list.
+236. scan_def didn't allow for the case warning_info=null.
+Version -60.0: [May 25]
+237. increased param_size.
+238. added <boolean><relation><boolean>.
+239. <Remove dead cubics> stopped too early if the first cubic was dead.
+240. bad_unary, bad_binary should distinguish pair from unknown pair.
+241. yet another "m<env_move[move_ptr]" test needs to be inserted.
+242. newinternal names need to go in the dump file.
+243. delete_mac_ref(v) should be delete_mac_ref(value(p)) in recycle_value.
+244. constant in <Decide...clockwise> was scaled instead of fraction.
+Version -59.0: [May 27]
+245. break up initialize routine into two parts (cf init_prim in TeX)
+Version -58.0: [May 28]
+246. do_ship_out should scan_expression, not scan_primary.
+247. offset_prep might clobber node q, so we need to search for q again.
+248. pair "1" = true! (blunder in type_test)
+249. allow strings x in `def f(expr x)=def g=x enddef enddef'.
+250. allow exprs in text parameters, in sufficiently easy cases.
+251. check right delimiters in macro_call.
+252. "Bad window number" message gave unscaled value.
+253. turnaround feature improves automatic rounding slightly.
+254. primaries changed to expressions in window and cull commands.
+255. scan_expression should make (0,0){0,0} a path, not a future path.
+256. showvariable and showtoken to allow lists; all shows made consistent.
+257. new internal quantity "windingcheck".
+258. delete warning message about edges never used.
+259. vardef: group the righthand side.
+260. show commands stop once each.
+261. cur_type should be vacuous after equation or assignment on outer level.
+Version -57.0: [June 4]
+262. added xyzzy diagnostic about effect of autorounding.
+263. make_moves now puts xi_corr,eta_corr into halving.
+[otherwise "draw (0,0)..(9,-.00002)" and "draw (0,-.00002)..(9,0)" fail badly!]
+Version -56.0: [June 6]
+264. smooth_moves changed completely; now is LR symmetric, cleaner.
+265. changed "unknown" to "known".
+266. pair to path conversion now done on length, makepen, reverse, etc.
+267. cycle now defined on arguments of any type.
+268. (re 218) sign was flipped in ceiling correction of <insert downward...>.
+[added union, subpath, penoffset, directiontime, intersectiontimes]
+
+Note: the first two draw statements in PENS.mf show an interesting effect.
+With autorounding, the curves are noticeably better, esp the small one.
+But there are two "holes", because of tiny discrepancies that I believe
+are unavoidable.
+Added later: Actually these are avoided by the new smooth_moves, but
+certain others will not be.
+Version -50.0 [June 30]
+269. smoothing to be shut off at the retrograde transitions
+270. more care needed in the rootfinding part of find_direction_time.
+271. improved error recovery after "Isolated expression".
+Version -40.0 [July 3] --- the first version to be "complete"!
+272. trivial change in <Exit...if the derivative $B(x_1,x_2,x_3;t)$...>.
+273. check that halfwords are large enough to hold edge/weight data.
+274. `path reverse (0,1)' should be true.
+275. xy_swap_edges might empty the structure; then x_reflect will fail!
+276. fix_offset was being done too often, due to improper range test.
+277. parameters come out even when tracingonline=0.
+278. step-until wasted r and didn't check syntax carefully.
+279. <Scan a group...> had typo: `line' for `group_line'.
+280. "You can't dump in a group" error was impossible.
+281. need better ETC cutoff in showmacro.
+282. print_exp needs to handle independents, because it's used by disp_var.
+283. suppress `#### xpart %CAPSULEnnnn' printouts.
+[added code for everyjob; this version wasn't complete after all!]
+Version -30.0 [July 9]
+284. need better error/help after ` if s1=s2' when the strings are unknown.
+285. removed autorounding>2; it was leading to more glitches than it was worth.
+286. envelope filling of a cycle to be done by two calls of fill_envelope.
+287. "null" changed to "vacuous".
+288. cyclic path inserted in another path should retain its last arc.
+289. introduce several dozen "put_get" errors for improved recovery.
+290. suppress "with autorounding" when autorounding hasn't been set.
+291. {loop value} came out even when tracingonline=0.
+292. show commands should wake up the terminal before showing their output.
+293. forgot error message in `if true else'.
+Version -20.0 [July 14]
+294. need to catch pens that are too large.
+295. make_eq dassn't change lhs (because this clobbers the memory links later).
+296. string usage is reported too high by showstats.
+297. bilin1 and add_mult_dep can call p_plus_fq with type(q)=proto_dependent.
+298. <Transform a known big node> forgot to recycle pp.
+299. in change number 286, the weight of the two paths should be the same.
+300. print_ln sometimes changed to print_nl("") in order to avoid blank lines.
+301. xyzzy to be combined with tracingedges.
+302. good3 entries should be 1 and 2 (not 1 and 0), to give desired symmetry.
+Version -10.0 [July 17]
+303. had to add `new_if_limit' to `conditional'.
+304. `else' can be incomplete as well as `if' and `elseif'.
+305. new help "You can't redefine a parameter."
+306. print_edges should use cur_edges, because print_weight does.
+307. cull shouldn't round; it should use ordinary inequalities.
+308. obliterated variable left `0' token hanging in scan_primary.
+309. forgot recycle_value(p) in <Evoke...>.
+310. forgot to check improper culling amounts.
+311. `on' to be changed to `inwindow'.
+312. >=max_tfm_dimen should be simply >.
+Version -9.0 [July 19]
+313. max_tfm_dimen needs to be decreased by design_size div 2^21.
+314. merge test data reporting into the screen display routines.
+315. use @# in printout at time of macro expansion tracing.
+316. bad recovery after "Incomplete string" error.
+317. @ should be usable as a parameter.
+318. spacing bad on `missing of' and `too many parameters' errors messages.
+319. keep track of largest str_ptr and pool_ptr values; showstats on two lines.
+Version -8.0 [July 26] [introduced new test routines to study memory usage]
+320. make_pen doesn't recycle the knots
+321. flush_below often says free_node(2) on node of size 3.
+322. make_eq should recycle and free; do_equation shouldn't
+323. re #298 and #309: should also free the value nodes!
+324. the replacement text of a bad_var definition should be recycled.
+325. token lists left unrecycled in error recovery of addto, cull, display.
+Version -7.0 [July 27]
+326. showall to put "(see the transcript file)" after >> if not tracingonline.
+327. remove redundant code: hex in print_the_digs; second l=1 in idlookup.
+328. procedures never called: b_open_in; round_scaled.
+329. need to zero cur_mod after back_expr in <Put the left bracket...>.
+330. <Print the coefficient...> now catches also numbers that round to 1.0.
+331. known_pair logic was obsolete; now it is massively simpler.
+332. fix_check_sum now zeroes the negative bytes; this simplifies other code.
+333. show_dependencies not to show parts of capsules.
+334. forgot to set fix_needed:=false!
+335. move fix_needed from add_or_subtract to dep_finish.
+336. test fix_needed in bilin1 and add_mult_dep.
+337. after back_expr in <Scan a mediation...>, forgot to unstash p.
+Version 0.0 [July 28] [Hurray! The preliminary TRAP test is fully passed.]
+338. corrected blunder in definition of trans_spec type. (found by Karney)
+339. less extreme starting values of gf_min_x and its cousins.
+340. uninitialized left_curl was possible. (found by John Hobby)
+341. In <Reduce...straight line...>, need to test sign before the `div 3' ops.
+342. In pyth_add, remove `+2' when dividing by 4, to prevent overflow.
+343. "Not a variable" changed to "Not a suitable variable".
+344. known_pair forgot to reset cur_type.
+345. round and floor procedures need to work in the presence of huge arguments.
+346. major revision to allow independent variables to disappear silently:
+346a. delete null_path and <Declare the null value routines>.
+346b. delete the hard part of ring_delete, and delete <Scold...for using...>.
+346c. stash/unstash/flush_cur_exp routines to allow independent type.
+346d. print_exp to allow a ring that contains only capsules.
+346e. <Zero out...> becomes <Recycle an independent variable> (major new code).
+346f. stash_in needs code to handle the case cur_type=independent.
+346g. negation needs code to handle the case cur_type=independent.
+346h. take_part needs code to handle the case cur_type=independent.
+346i. do_binary needs code to handle either or both operands independent.
+346j. frac_mult needs code to handle the case cur_type=independent.
+346k. make_eq and try_eq too.
+346l. linear_eq needs to check if cur_exp=x and cur_type=independent.
+346m. linear_eq displays new dependency only when lhs is interesting.
+347. minor improvement for coding style/brevity: the "interesting" function.
+348. test `if t<independent' had been left out of print_exp (was dirty PASCAL).
+349. (begingroup save x;x+1000 endgroup,0) caused subtle bug during unsave.
+350. print_type(known) changed to "known numeric" for consistency.
+351. In <Change...to proto_dependent>, didn't watch for coefficients zeroed.
+352. check_mem now checks also the links in the dependency lists.
+353. null_pen initialization belongs in <Initialize tab...>, not <Set init...>.
+354. fix_dependencies has to worry about coefficients dropping to zero.
+355. add tracing to frac_mult.
+356. need cur_sym>0 at the time of end_read_terminal. (found by S Robinson)
+Version 0.1 [August 30]
+357. Don't complain about winding_number<=0 when doing a doublepath.
+358. Need to test for max_coef=0 in offset_prep.
+359. Cusp detection should allow for more rounding error.
+360. Major change to path syntax, allowing {dir}..{dir} path joins.
+360a. `Fragments' disappear; new_fragment becomes new_knot.
+360b. print_path has simpler conventions.
+360c. future_path type disappears.
+360d. left_brace renumbered and removed from scan_tertiary.
+360e. some scan_tertiary code moves to new subroutine scan_direction.
+360f. scan_expression has a bunch of new code.
+361. scan_expression shouldn't have returned after cycle_hit.
+362. abort_path, scrap_knot logic removed from scan_expression.
+Version 0.2 [September 12]
+363. new operator: makepath <pen primary>.
+364. define point/precontrol/postcontrol at endpoints and beyond. (JDH)
+365. union replaced by +; negation and subtraction allowed on edges.
+366. another new operator: totalweight <edges primary>. (JDH's idea)
+367. undelimited parameters may be preceded by an optional = or :=.
+368. base_area_length was wrong. (affects CH files)(found by Pavel)
+369. internal names to be allowable in suffixes.
+370. label not_found was misplaced in do_add_to. (found by PasMESA translator)
+371. progress report should be given at time of shipout.
+372. procedures make_choices, make_spec,fill_envelope split into shorter pieces.
+373. locals of cubic_intersection made global so that people could split it.
+Version 0.3 [September 27]
+374. allow <future pen> ::= <pen> <transform>
+375. equation that's off by .0001 shouldn't be called inconsistent.
+376. bug in skew: must compute x_coord(q) and y_coord(q) exactly.
+377. right/left/up/down to be assigned to octants 1/5/2/6; was 1/4/2/7.
+378. boundedness to be allowed with any tension, and one-sidedly.
+379. eliminate coordinate nodes in path lists by passing angles instead (JDH).
+380. known_pair to free cur_exp after error msgs that might showdependencies.
+381. scan_primary sometimes accessed num before it had a value (found by Pavel).
+382. invalid characters should cause error message (suggested by PMB).
+Version 0.4 [October 12]
+383. allow `0' in response to error prompts.
+384. put loop value on error context lines.
+385. change `ord' to `ASCII'.
+386. scantokens <string primary> to be permitted; readterminal goes away.
+387. expandafter <token> to be permitted.
+388. improved overflow conventions on make_fraction, make_scaled.
+389. variable=<value over 4096> should get its own error message.
+390. nice_pair first argument can be any integer.
+391. new feature, shortshow commands that don't pause.
+392. "harmless" bug in negate_edges, the sorted list can get out of sorts.
+393. ni too skimpy (15 instead of 63). (JDH)
+394. loop_ptr not initialized. (found by Paul Richards)
+395. bug in <Find the approximate type...>, q=null should goto done1. (Richards)
+396. empty_edges macro added for readability.
+397. x_reflect_edges might as well fix the offset as it goes.
+398. blunder: frozen_bad_vardef had the wrong eq_type.
+399. "name" changed to "tag".
+400. check_arith inserted after division of numeric tokens.
+401. stop_bit was not initialized in <Compile a ligature/kern...>.
+402. char 127 to be a string of length 1; slow_print added (therefore).
+403. pyth_sub added to the repertoire.
+404. minor change to calls on "confusion" in make_fraction, make_scaled. (JJW)
+Version 0.5 [November 9]
+405. 4095.999999 should be erroneous.
+406. length <pair> to give the absolute value; argd changed to "angle".
+407. get_next changed to get_x_next wherever possible.
+408. z1..z2{curl 0} should be equivalent to z1..{curl 0}z2.
+409. scantokens "" should be fast.
+410. allow undelimited suffix and text parameters.
+411. warningcheck to allow large variable values passed over silently.
+412. "edges" changed to "picture".
+413. "winding" changed to "turning".
+414. <If consecutive knots...> had typo, "p" for "q".
+415. elliptical pens should have axis symmetry.
+416. slow_add introduced to catch arithmetic overflow on addition.
+417. add a turningnumber primitive.
+418. no carriage return between ">>" and "Edge structure...".
+419. install new memory management routines (from TeX version 1.3).
+420. generalized cull command. (suggested by Bruce Leban)
+421. bad goto: `x..' reports that x is vacuous, loses value of x.
+422. shortshows replaced by an internal variable "showstopping".
+423. major change, capsule tokens: lots of code and restrictions gone! (JDH)
+424. substring(a,b), subpath(a,b) to reverse the result when a>b.
+425. new GF format: z goes away. (suggested by ALS)
+426. another GF mod: chardw replaced by chardx/chardy, which are scaled. (PMB)
+427. make `&' have the same precedence always (not different for strings).
+428. wrong error message for 2"s" (bug introduced in change 369).
+429. variable l in show_context has to be declared type integer.
+430. bug in chop_path when both limits are large.
+Version 0.6 [December 10]
+431. xoffset and yoffset to be added by shipout. [this affects GF comments]
+432. wake_up_terminal, not t_open_out, before "Ouch..." (Scott Robinson)
+433. undelimited suffix parameters to allow an optional delimiter, disallow =.
+434. showall... to be eliminated; tracingcapsules added.
+435. allow undelimited parameters after delimited ones.
+436. nullpen test in addto should test for any one-point pen.
+437. granularity parameter to affect autorounding (Bruce Leban)
+[this leads to major improvements suggested by JDH; lots of code changes!]
+[basically, make_spec is now responsible for autorounding; fill_spec just fills]
+438. node_size overflow problem must be prevented. (Paul Richards)
+439. allow unary + with a picture.
+440. nullpen should transform quickly to itself, if not shifted.
+441. print_edges should skip over null rows, if it doesn't already.
+442. open_base_file improved (following TeX's change number 302).
+443. output initialization improved (following TeX's change number 303).
+444. operators shouldn't fail because future pen isn't a pen. (JDH)
+445. intersection routine to quit in hard cases. (DRF)
+446. angle routine was off by epsilon on negative arguments. (Karney)
+447. octant assignment should look ahead further in ambiguous cases. (JDH)
+448. <Compute the incoming...> forgot that right_type(r)=endpoint could happen.
+449. turning_number calculated directly, not times 8.
+450. floor_scaled made more efficient by trading subtraction for multiplication.
+451. doublepath autorounding to compromise between east and west. (JDH)
+452. codes of picture_type and path_type interchanged, to simplify a "case".
+Version 0.7 [January 17, 1985]
+453. def to allow both := and =. (NB)
+454. "keeping" and "dropping" instead of "including" and "excluding". (HWT)
+455. (see the transcript...): why, when tracingonline>0?
+456. dead cubics need to be removed also before xy_round. (NB)
+457. [re 433] I said get_x_next twice; a blunder.
+Version 0.75 [January 23, 1985]
+458. Abbreviated boc command makes GF format more attractive for lowres. (GusF)
+Version 0.76 [February 2]
+459. known and unknown might as well both be primitive.
+460. ab_vs_cd(a-d,b,c-b,d) simplifies to ab_vs_cd(a,b,c,d). (JDH)
+461. (from change 435) <Absorb undelimited...> must use k, not n.
+462. (from change 458) max_new_row added, since 165 wasn't updated to 164.
+Version 0.77 [February 16]
+463. abbreviated version of tracingspecs is desired for turning number errors.
+464. improved octant number in pathological cases of quadrant_subdivide (JDH)
+465. xoffset,yoffset communicated to GF file when proofing>0.
+466. Poirot changed to Marple.
+467. reverse<cycle> starts the reversed path at the wrong time.
+468. Extra help given after `undefined coordinate' errors.
+469. Keep segment numbers from overflowing max_halfword. (JDH)
+470. Ditto for pen offset slope numbers.
+471. n_magic had min_halfword with wrong sign. (John Johnson)
+Version 0.80 [April 1]
+472. In errhelp, % means <return>, %% means %. (BPL)
+473. tracing of envelopes should give symbolic octant names.
+474. (-x mod y) should be ((-x) mod y) in good_val.
+475. crossingpoint could overflow on 32-bit machines. (BPL)
+476. Improvements to abbreviated format of number 463.
+Version 0.81 [April 4]
+477. `I hide(showdependencies)' in hint to become `I ???'.
+478. print_strange shouldn't wake up the terminal in scroll mode. (cf 463)
+479. flush_list procedure made a bit faster. (DRF)
+480. bounded velocities to be multiplied by .999 for safety.
+481. Detect error in declaration that tries to extend a vardef.
+482. print_strange puts turns in parentheses (cf 463).
+483. make_name_string shouldn't ever cause string space overflow.
+484. allow <picture primary> xscaled m yscaled n.
+485. checksum should consider values relative to designsize. (DRF)
+[I also increased max_strings to 2000.]
+
+[Note: Neenie found a case where missing pixels can occur, due to
+inconsistent rounding between left-to-right and right-to-left subdivision:
+pickup pencircle; draw
+(0,126)..controls (130.29451,126) and (288,126.00002)
+ ..(288,36)..controls (288,143.99998) and (132.97438,144)
+ ..(0,144)..controls (0,138) and (0,132)
+ ..cycle;
+The "right" way to fix this would be to develop a make_spec routine for
+non-cycles, and to copy a reversed spec, so that double paths would be
+guaranteed self-inverse. However, my later experiments showed that
+autorounding wasn't nearly as useful as I had expected it to be, hence I
+decided not to waste time beefing up this routine; no satisfactory
+automatic approach to rounding occurs to me.]
+Version 0.90 [May 10]
+486. 180-degree turns to be clockwise for half of doublepath cycles.
+487. introduce fillin parameter.
+488. `numeric_type' moved before `known', so that print_exp works (Richards).
+489. numeric_type as unary op should include independent in its range (cf 346).
+Version 0.91 [May 13]
+490. show_token_list gets null_tally parameter.
+491. if bad>0, change the code as in TeX changes 315, 316.
+492. batchmode change as in TeX 317.
+493. "and double autorounding" to be traced, if appropriate.
+494. introduce tracingrestores.
+         *`restoring a bad variable'?
+495. put decimal number into gf extension
+496. mediation put into scan_primary, so that round .5[a,b] works properly.
+497. cubic_intersection now has |tol| to compensate for rounding errors.
+498. find_direction_time needs to worry about degenerate case x3=y3=0.
+499. crossing_point(a,b,0) now yields fraction_one if a,b>0.
+500. diag_round shouldn't insist that b-a is even (see below).
+501. macro_call will show_macro with much larger limit.
+502. TFM file statistics are logged too.
+
+* Here's an example (found by Neenie) explaining bugfix 500:
+autorounding:=2; draw
+(7.03159,-9.31831)..controls (12.14732,-9.4386) and (17.4299,-6.82948)
+ ..(21.60132,0)..controls (27.47417,9.61507) and (37.87402,15.58647)
+ ..(43.74687,25.20154)..controls (51.16223,37.34201) and (57.31,50.171)
+ ..(63.45776,63.00002) withpen pencircle;
+The missing pixels are due to the following curious circumstances: (1) the
+middle cubic splits into three, when subdividing into octants; (2) the reverse
+curve splits too but with slightly different rounding, off by 1; (3) the old
+diag_round routine, when it ensures that b-a is even, computes aa=a+1 on
+one side of the curve, but aa=a-1 on the other side, thus making the
+rounding "safe" on only one side. (Namely, on one side we have consecutive
+values
+  b=1317666 a=1310720
+  b=1329617 a=1310721
+and on the other side,
+  b=-1329618 a=-1310720
+  b=-1317667 a=-1310721.)
+
+* Here's an example (by JDH) showing the necessary of bugfix 497:
+path p[];
+p1 = (1,0)..controls (1,0.10493) and (0.98347,0.20921)
+     ..(0.95105,0.30902)..controls (0.91862,0.40881) and (0.8707,0.50288)
+     ..(0.80902,0.58778);
+p2 = (0,0)..controls (0.63403,0.20601) and (1.26807,0.41203)
+     ..(1.9021,0.61804);
+show p1 intersectiontimes p2;    % (-1,-1), without `tol'
+pickup pencircle;
+currenttransform := identity scaled 150;
+draw p1; draw p2;
+showit;          % but they clearly intersect
+Version 0.95 [Aug 12]
+503. `Se' changed to `SSE', etc. (suggested by RFS)
+504. Inconsisting diagonal rounding was introduced in bugfix 500.
+
+[the following lines from @<Determine the before...@> in diag_round:
+    if aa>bb then cc:=dd-half(aa-bb-1)@+else cc:=dd-half(aa-bb+1)
+  if a>b then c:=d-half(a-b-1)@+else c:=d-half(a-b+1)
+were replaced respectively by:
+    if right_type(p)>switch_x_and_y then cc:=dd-half(aa-bb+1)
+    else cc:=dd-half(aa-bb-1)
+  if right_type(p)>switch_x_and_y then c:=d-half(a-b-1)
+  else c:=d-half(a-b+1)
+in order to make the rounding consistent on adjacent octants;
+the following command caused `this can't happen':
+fill (33,7)..controls (32.63094,5.70827) and (32.06163,3.716)
+ ..(31.59488,3.36667)..controls (31.10509,3.00009) and (29.14824,3)
+ ..(27.85318,3)..controls (27.85286,3) and (23.84952,3)
+ ..(23.8492,3)..controls (23.73282,2) and (23.61646,1)
+ ..(23.50008,0)..controls (26.66672,0) and (29.83336,0)
+ ..(33,0)..controls (33.66667,2.33333) and (34.33333,4.66667)
+ ..(35,7)..controls (34.33333,7) and (33.66667,7)
+ ..cycle;]
+Version 0.96 [Aug 17]
+505. allow comparison of transforms. [test by trying t=t when t is new...]
+506. {restoring...} shouldn't get through when tracingonline=0.
+507. better error message needed on `interim alpha:=0', `interim 0:=0'.
+508. make_op_def should put parameters in the other order.
+509. <Worry about...> should say get_x_next, not get_next.
+510. unif_rand to allow negative x, save on error messages.
+511. tidy up chop_string when b<0 and/or a>l.
+512. randomseed is automatically logged.
+513. change 495 messed up if gf file couldn't be opened. (found by DRF)
+[In INIMF.CH, 3-character extensions now have 0--9 or A--Z as leading digit.]
+Version 0.97 [Sep 5]
+514. a[b,c] to be tried only if a is numeric type.
+515. simplified the code for length_op(string_type).
+516. citations of `Chapter xx' now replaced by correct references.
+517. <Log the subfile sizes...> to be in stat...tats version only.
+518. remove extra space after <insert> and <scantokens>.
+519. offsets should be included in the tracingoutput output.
+520. a vacuous expression should be considered known.
+521. charlist syntax changed from commas to colons.
+[also the WAITS version command-line reader was fixed to handle `^^W']
+Version 0.99 [Sep 24]
+522. vardef's begingroup...endgroup should be accessible.
+523. allow an empty expression in for loops.
+Version 0.999 [Oct 1]
+524. "charfam" changed to "charext".
+525. variable tt makes get_node slightly faster. (PROFILE suggests this)
+526. cur_cmd<=max should be tested before cur_cmd>=min. (PROFILE)
+527. fast_get_avail used in cur_tok and scan_primary. (PROFILE)
+Version 0.9999 [Oct 27]
+528. Major change to representation of independent variables
+ ("serial number" added so that MF's equation solving doesn't depend
+ on vagaries of storage allocation)
+ [module number change: new module between old 585 and 586]
+ [in terms of new numbering, modules 232, 585--587, 589, 594, 597,
+    601, 608, 610, 816--817, 855, 1198--1199 were affected]
+[I also reordered some of the cases in print_op, module 189,
+so that the program could be condensed in published version]
+Version 0.99999 [Nov 13]
+529. forgot to decrease three_l in change 497!
+530. cubic_intersection to give approximation if max_patience exceeded.
+[the following example, found by NB, motivated this change:
+ show (
+  (36.00104,26.99951)..controls (36.00131,26.99979) and (36.00146,27.00017)
+   ..(36.00146,27.00055)
+   )intersectiontimes(
+  (36,27.00055)..controls (45.17148,21.12364) and (55.83588,18)
+   ..(66.72873,18)
+  );]
+Version 0.999999 [Dec 2]
+531. hold_head needed (scan_toks calls cur_tok calls copy_edges). (D. Kosower)
+Version 1.0 [January 4, 1986]
+532. Optimization in module 1174, suggested by LER (3 Feb 86)
+@x
+  if delta=0 then gf_out(skip0)
+  else  begin gf_out(skip1); gf_out(delta);
+    end
+@y
+  begin gf_out(skip1); gf_out(delta);
+  end
+@z
+*** Late copies of version 1.0 include this correction;
+in particular, the program listing in Volume D was updated (with scissors)!
+Changes subsequent to `Version 1.0' as published in C&T, Volume D:
+533. Inconsistent punctuation in user messages (found by Karl Berry, June 86)
+@x module 1134
+print_nl("Font metrics written on "); print(metric_file_name);
+@y
+print_nl("Font metrics written on "); print(metric_file_name); print_char(".");
+@z (that was installed in version 1.1)
+
+534. Possible arithmetic overflows (found by Klaus Guntermann, July 86)
+@x module 496
+while max_coef<fraction_one do
+@y
+while max_coef<fraction_half do
+@z (that was installed in version 1.2)
+
+535. Possible loop in nonstopmode (found by Chris Thompson, July 86)
+@x module 1206
+    @<Finish the \.{TFM} file@>;
+@y
+    internal[fontmaking]:=0; {avoid loop in case of fatal error}
+    @<Finish the \.{TFM} file@>;
+@z (that too was installed in version 1.2)
+
+536. Double rounding error should be avoided in make_ellipse (JDH, 22 Nov 86)
+@x module 533
+d:=take_fraction(d,delta);
+alpha:=abs(u); beta:=abs(v);
+if alpha<beta then
+  begin delta:=alpha; alpha:=beta; beta:=delta;
+  end; {now $\alpha=\max(\vert u\vert,\vert v\vert)$,
+      $\beta=\min(\vert u\vert,\vert v\vert)$}
+if internal[fillin]<>0 then d:=d-take_fraction(internal[fillin],beta+beta);
+d:=(d+4) div 8; alpha:=alpha div half_unit;
+@y
+alpha:=abs(u); beta:=abs(v);
+if alpha<beta then
+  begin alpha:=abs(v); beta:=abs(u);
+  end; {now $\alpha=\max(\vert u\vert,\vert v\vert)$,
+      $\beta=\min(\vert u\vert,\vert v\vert)$}
+if internal[fillin]<>0 then
+  d:=d-take_fraction(internal[fillin],make_fraction(beta+beta,delta));
+d:=take_fraction((d+4) div 8,delta); alpha:=alpha div half_unit;
+@z (That was the reason for version 1.3)
+
+537. Trivial change to a help message (version number is still 1.3).
+@x module 1086
+  ("Pretend that you're Miss Marple, examine all clues,")@/
+@y
+  ("Pretend that you're Miss Marple: Examine all clues,")@/
+@z
+
+538. Storage allocation can be more elegant and efficient (4/21/87)
+@x module 169
+if r=p then if ((rlink(p)<>rover) or (llink(p)<>rover)) then
+@y
+if r=p then if rlink(p)<>p then
+@z
+
+539. Unused variables can be eliminated. (Found by John Sauter, 5/5/87)
+@x module 158
+@<Glob...@>=
+@!temp_ptr:pointer; {a pointer variable for occasional emergency use}
+
+@y (I used it only in my change file!)
+@z
+@x module 280
+@!r,@!s,@!t:pointer; {registers for list traversal}
+@y
+@!s,@!t:pointer; {registers for list traversal}
+@z
+@x module 284
+@!sine,@!cosine:fraction; {trig functions of various angles}
+@y (the declarations in module 281 are correct, but in 284 they're superfluous)
+@z
+@x module 497
+var @!q,@!ww:pointer; {for list manipulation}
+@!du,@!dv:scaled; {for slope calculation}
+@!t0,@!t1,@!t2:integer; {test coefficients}
+@!t:fraction; {place where the derivative passes a critical slope}
+@!s:fraction; {slope or reciprocal slope}
+@!v:integer; {intermediate value for updating |x0..y2|}
+begin loop
+  begin q:=link(p); right_type(p):=k;
+@y
+var @!ww:pointer; {for list manipulation}
+@!du,@!dv:scaled; {for slope calculation}
+@!t0,@!t1,@!t2:integer; {test coefficients}
+@!t:fraction; {place where the derivative passes a critical slope}
+@!s:fraction; {slope or reciprocal slope}
+@!v:integer; {intermediate value for updating |x0..y2|}
+begin loop
+  begin right_type(p):=k;
+@z
+@x module 652
+@!s:0..param_size; {value of |param_start| on the current level}
+@y who knows why that line was there?
+@z
+@x module 862
+var @!p,@!q,@!r:pointer; {for list manipulation}
+@y
+var @!p:pointer; {for list manipulation}
+@z
+@x module 985
+@!vv:scaled; {initial value of |v|}
+@!q:pointer; {successor of |p|}
+begin vv:=v; p:=cur_exp;@/
+@y
+@!q:pointer; {successor of |p|}
+begin p:=cur_exp;@/
+@z
+@x module 1059
+@!t:small_number; {variant of |with_option|}
+@y
+@z
+
+540. Typo suppresses an error detection (Chris Thompson, 2May88)
+@x module 963
+ if txy mod unity=0 then if tyy mod unity=0 then
+@y
+ if txx mod unity=0 then if tyy mod unity=0 then
+@z
+
+541. get_x_token can lose a scanned declared variable (Chris Thompson, 4May88)
+@x module 1011
+if equiv(x)=null then new_root(x);
+@y
+@z
+@x module 1011
+done:scan_declared_variable:=h;
+@y
+done: if eq_type(x)<>tag_token then clear_symbol(x,false);
+if equiv(x)=null then new_root(x);
+scan_declared_variable:=h;
+@z
+
+542. Avoid negative divisor rounding upward (Chris Thompson, fixed 19Jun88)
+@x module 168
+else t:=(lo_mem_max+hi_mem_min+2) div 2; {|lo_mem_max+2<=t<hi_mem_min|}
+@y
+else t:=lo_mem_max+1+(hi_mem_min-lo_mem_max)div 2; {|lo_mem_max+2<=t<hi_mem_min|}
+@z
+
+543. Better strategy when near memory overflow (Chris Thompson)
+@x module 168
+begin if lo_mem_max+1000<hi_mem_min then t:=lo_mem_max+1000
+@y
+begin if hi_mem_min-lo_mem_max>=1998 then t:=lo_mem_max+1000
+@z
+
+544. Avoid fatal_error after terminal eof (Tim Morgan, reported 25Oct88)
+@x module 66 [serious problem occurred if this was called in open_log_file]
+if not input_ln(term_in,true) then fatal_error("End of file on the terminal!");
+@y
+if not input_ln(term_in,true) then t_open_in;
+@z
+
+545. Force terminal output when open_log_file aborts (6Nov88)
+@x module 789
+  begin print_err("I can't write on file `");
+@y
+  begin selector:=term_only; print_err("I can't write on file `");
+@z
+
+546. By popular request, undo #544 and fix the bug a more complex way.
+@x module 66 [this undoes change #544]
+if not input_ln(term_in,true) then t_open_in;
+@y
+if not input_ln(term_in,true) then fatal_error("End of file on the terminal!");
+@z
+@x module 87 [now we get to the new stuff]
+begin if job_name>0 then selector:=term_and_log
+@y
+begin if log_opened then selector:=term_and_log
+@z
+@x module 88
+  error;
+@y
+  if log_opened then error;
+@z
+@x module 782
+@!job_name:str_number; {principal file name}
+@y
+@!job_name:str_number; {principal file name}
+@!log_opened:boolean; {has the transcript file been opened?}
+@z
+@x module 783
+@<Initialize the output...@>=job_name:=0;
+@y
+@<Initialize the output...@>=job_name:=0; log_opened:=false;
+@z
+@x module 788
+selector:=log_only;
+@y
+selector:=log_only; log_opened:=true;
+@z
+@x module 789
+begin if interaction<scroll_mode then {bypass |fatal_error|}
+  begin selector:=term_only; print_err("I can't write on file `");
+@.I can't write on file x@>
+  print_file_name(cur_name,cur_area,cur_ext); print("'.");@/
+  job_name:=0; history:=fatal_error_stop; jump_out;
+  end; {abort the program without a log file}
+@y
+begin selector:=term_only;
+@z
+@x module 1023 [this change is optional, but it's a slight improvement]
+  if job_name<>0 then selector:=selector+2;
+@y
+  if log_opened then selector:=selector+2;
+@z
+@x module 1205
+if job_name>0 then
+@y
+if log_opened then
+@z
+@x module 1208
+if job_name>0 then {the log file is open}
+@y
+if log_opened then
+@z
+
+547. String startup problems corresponding to TeX change 355 (17 Jul 89)
+@x module 30 (Warning: This affects most change files!)
+        overflow("buffer size",buf_size);
+@:METAFONT capacity exceeded buffer size}{\quad buffer size@>
+@y
+        @<Report overflow of the input buffer, and abort@>;
+@z
+@x module 34
+consist of the remainder of the command line, after the part that invoked \MF.
+@y
+consist of the remainder of the command line, after the part that invoked \MF.
+
+The first line is special also because it may be read before \MF\ has
+input a base file. In such cases, normal error messages cannot yet
+be given. The following code uses concepts that will be explained later.
+
+@<Report overflow of the input buffer, and abort@>=
+if base_ident=0 then
+  begin write_ln(term_out,'Buffer size exceeded!'); goto final_end;
+@.Buffer size exceeded@>
+  end
+else begin cur_input.loc_field:=first; cur_input.limit_field:=last-1;
+  overflow("buffer size",buf_size);
+@:METAFONT capacity exceeded buffer size}{\quad buffer size@>
+  end
+@z
+@x module 1193
+k:=pool_ptr-4; undump_four_ASCII
+@y
+k:=pool_ptr-4; undump_four_ASCII;
+init_str_ptr:=str_ptr; init_pool_ptr:=pool_ptr;@/
+max_str_ptr:=str_ptr; max_pool_ptr:=pool_ptr
+@z
+@x module 1204
+tini@/
+@y
+init_str_ptr:=str_ptr; init_pool_ptr:=pool_ptr;@/
+max_str_ptr:=str_ptr; max_pool_ptr:=pool_ptr; fix_date_and_time;
+tini@/
+@z
+@x module 1204
+init_str_ptr:=str_ptr; init_pool_ptr:=pool_ptr;@/
+max_str_ptr:=str_ptr; max_pool_ptr:=pool_ptr;@/
+@y
+@z
+
+548. Major changes to allow 8-bit input, cf. TeX82 #359 (11 Sep 89).
+@x module 18
+@!ASCII_code=0..127; {seven-bit numbers}
+@y
+@!ASCII_code=0..255; {eight-bit numbers}
+@z
+@x module 19
+@d last_text_char=127 {ordinal number of the largest element of |text_char|}
+
+@<Local variables for init...@>=
+@!i:0..last_text_char;
+@y
+@d last_text_char=255 {ordinal number of the largest element of |text_char|}
+
+@<Local variables for init...@>=
+@!i:integer;
+@z
+@x module 21
+xchr[0]:=' '; xchr[@'177]:=' ';
+  {ASCII codes 0 and |@'177| do not appear in text}
+@y
+@z
+@x module 22
+for i:=1 to @'37 do xchr[i]:=' ';
+@y changing ' ' to chr(i) here will allow all 8-bit characters to get in
+for i:=0 to @'37 do xchr[i]:=' ';
+for i:=@'177 to @'377 do xchr[i]:=' ';
+@z
+@x module 23
+for i:=1 to @'176 do xord[xchr[i]]:=i;
+@y
+for i:=@'200 to @'377 do xord[xchr[i]]:=i;
+for i:=0 to @'176 do xord[xchr[i]]:=i;
+@z
+@x module 37
+@<Types...@>=
+@!pool_pointer = 0..pool_size; {for variables that point into |str_pool|}
+@!str_number = 0..max_strings; {for variables that point into |str_start|}
+
+@ @<Glob...@>=
+@!str_pool:packed array[pool_pointer] of ASCII_code; {the characters}
+@y [OK to make si(#)==#-128 and so(#)==#+128 (without parens) in change files]
+Some \PASCAL\ compilers won't pack integers into a single byte unless the
+integers lie in the range |-128..127|. To accommodate such systems
+we access the string pool only via macros that can easily be redefined.
+
+@d si(#) == # {convert from |ASCII_code| to |packed_ASCII_code|}
+@d so(#) == # {convert from |packed_ASCII_code| to |ASCII_code|}
+
+@<Types...@>=
+@!pool_pointer = 0..pool_size; {for variables that point into |str_pool|}
+@!str_number = 0..max_strings; {for variables that point into |str_start|}
+@!packed_ASCII_code = 0..255; {elements of |str_pool| array}
+
+@ @<Glob...@>=
+@!str_pool:packed array[pool_pointer] of packed_ASCII_code; {the characters}
+@z
+@x module 41
+begin str_pool[pool_ptr]:=#; incr(pool_ptr);
+@y
+begin str_pool[pool_ptr]:=si(#); incr(pool_ptr);
+@z
+@x module 45
+  begin if str_pool[j]<>buffer[k] then
+@y
+  begin if so(str_pool[j])<>buffer[k] then
+@z
+@x module 47
+var k,@!l:0..127; {small indices or counters}
+@y
+var k,@!l:0..255; {small indices or counters}
+@z
+@x module 47
+@<Make the first 128 strings@>;
+@y
+@<Make the first 256 strings@>;
+@z
+@x module 48
+@ @<Make the first 128...@>=
+for k:=0 to 127 do
+  begin if (@<Character |k| cannot be printed@>) then
+    begin append_char("^"); append_char("^");
+    if k<@'100 then append_char(k+@'100)
+    else append_char(k-@'100);
+@y
+@ @d app_lc_hex(#)==l:=#;
+  if l<10 then append_char(l+"0)@+else append_char(l-10+"a")
+
+@<Make the first 256...@>=
+for k:=0 to 255 do
+  begin if (@<Character |k| cannot be printed@>) then
+    begin append_char("^"); append_char("^");
+    if k<@'100 then append_char(k+@'100)
+    else if k<@'200 then append_char(k-@'100)
+    else begin app_lc_hex(k div 16); app_lc_hex(k mod 16);
+      end;
+@z
+@x module 59
+  begin print_char(str_pool[j]); incr(j);
+@y
+  begin print_char(so(str_pool[j])); incr(j);
+@z
+@x module 60
+  begin print(str_pool[j]); incr(j);
+@y
+  begin print(so(str_pool[j])); incr(j);
+@z
+@x module 85
+  begin if str_pool[j]<>"%" then print(str_pool[j])
+  else if j+1=str_start[err_help+1] then print_ln
+  else if str_pool[j+1]<>"%" then print_ln
+@y
+  begin if str_pool[j]<>si("%") then print(so(str_pool[j]))
+  else if j+1=str_start[err_help+1] then print_ln
+  else if str_pool[j+1]<>si("%") then print_ln
+@z
+@x module 199
+char_class[127]:=invalid_class;
+@y
+for k:=127 to 255 do char_class[k]:=invalid_class;
+@z
+@x module 200
+@d hash_is_full == (hash_used=1) {test if all positions are occupied}
+@d eq_type(#) == eqtb[#].lh {the current ``meaning'' of a symbolic token}
+@d equiv(#) == eqtb[#].rh {parametric part of a token's meaning}
+@d hash_base=129 {hashing actually starts here}
+@y [incidentally I fixed a bug re hash overflow here]
+@d eq_type(#) == eqtb[#].lh {the current ``meaning'' of a symbolic token}
+@d equiv(#) == eqtb[#].rh {parametric part of a token's meaning}
+@d hash_base=257 {hashing actually starts here}
+@d hash_is_full == (hash_used=hash_base) {are all positions occupied?}
+@z
+@x module 210
+for j:=0 to l-1 do buffer[j]:=str_pool[k+j];
+cur_sym:=id_lookup(0,l);@/
+if s>=128 then {we don't want to have the string twice}
+@y
+for j:=0 to l-1 do buffer[j]:=so(str_pool[k+j]);
+cur_sym:=id_lookup(0,l);@/
+if s>=256 then {we don't want to have the string twice}
+@z
+@x module 223
+begin c:=char_class[str_pool[str_start[r]]];
+@y
+begin c:=char_class[so(str_pool[str_start[r]])];
+@z
+@x module 717
+  begin buffer[first]:=str_pool[j]; incr(j); incr(first);
+@y
+  begin buffer[first]:=so(str_pool[j]); incr(j); incr(first);
+@z
+@x module 774
+for j:=str_start[a] to str_start[a+1]-1 do append_to_name(str_pool[j]);
+for j:=str_start[n] to str_start[n+1]-1 do append_to_name(str_pool[j]);
+for j:=str_start[e] to str_start[e+1]-1 do append_to_name(str_pool[j]);
+@y
+for j:=str_start[a] to str_start[a+1]-1 do append_to_name(so(str_pool[j]));
+for j:=str_start[n] to str_start[n+1]-1 do append_to_name(so(str_pool[j]));
+for j:=str_start[e] to str_start[e+1]-1 do append_to_name(so(str_pool[j]));
+@z
+@x module 912
+  else  begin cur_exp:=round_unscaled(cur_exp) mod 128; cur_type:=string_type;
+    if cur_exp<0 then cur_exp:=cur_exp+128;
+@y
+  else  begin cur_exp:=round_unscaled(cur_exp) mod 256; cur_type:=string_type;
+    if cur_exp<0 then cur_exp:=cur_exp+256;
+@z
+@x module 913
+  else n:=str_pool[str_start[cur_exp]]
+@y
+  else n:=so(str_pool[str_start[cur_exp]])
+@z
+@x ibid
+    begin m:=str_pool[k];
+@y
+    begin m:=so(str_pool[k]);
+@z
+@x module 976
+for k:=str_start[a] to str_start[a+1]-1 do append_char(str_pool[k]);
+for k:=str_start[b] to str_start[b+1]-1 do append_char(str_pool[k]);
+@y
+for k:=str_start[a] to str_start[a+1]-1 do append_char(so(str_pool[k]));
+for k:=str_start[b] to str_start[b+1]-1 do append_char(so(str_pool[k]));
+@z
+@x module 977
+  for k:=str_start[s]+b-1 downto str_start[s]+a do append_char(str_pool[k])
+else for k:=str_start[s]+a to str_start[s]+b-1 do append_char(str_pool[k]);
+@y
+  for k:=str_start[s]+b-1 downto str_start[s]+a do append_char(so(str_pool[k]))
+else for k:=str_start[s]+a to str_start[s]+b-1 do append_char(so(str_pool[k]));
+@z
+@x module 1103
+  begin c:=str_pool[str_start[cur_exp]]; goto found;
+@y
+  begin c:=so(str_pool[str_start[cur_exp]]); goto found;
+@z
+@x module 1160
+  for k:=str_start[s] to str_start[s+1]-1 do gf_out(str_pool[k]);
+  end;
+if t<>0 then for k:=str_start[t] to str_start[t+1]-1 do gf_out(str_pool[k]);
+@y
+  for k:=str_start[s] to str_start[s+1]-1 do gf_out(so(str_pool[k]));
+  end;
+if t<>0 then for k:=str_start[t] to str_start[t+1]-1 do gf_out(so(str_pool[k]));
+@z
+@x module 1192
+  w.b0:=str_pool[k]; w.b1:=str_pool[k+1];
+  w.b2:=str_pool[k+2]; w.b3:=str_pool[k+3];
+@y [often qi(so(x))=x, but not e.g. when "quarterwords" are two bytes]
+  w.b0:=qi(so(str_pool[k])); w.b1:=qi(so(str_pool[k+1]));
+  w.b2:=qi(so(str_pool[k+2])); w.b3:=qi(so(str_pool[k+3]));
+@z
+@x module 1193
+  str_pool[k]:=w.b0; str_pool[k+1]:=w.b1;
+  str_pool[k+2]:=w.b2; str_pool[k+3]:=w.b3
+@y
+  str_pool[k]:=si(qo(w.b0)); str_pool[k+1]:=si(qo(w.b1));
+  str_pool[k+2]:=si(qo(w.b2)); str_pool[k+3]:=si(qo(w.b3))
+@z
+
+549. Make ".base" more easily switchable (see TeX82 log #369).
+@x module 775 gets a new definition
+@y
+@d base_extension=".base" {the extension, as a \.{WEB} constant}
+@z now replace ".base" by base_extension in modules 784 and 1200.
+
+550. "This can't happen" happened because of nonmonotonic rounding
+ (bug found by Mark Eklof, fixed 7 Oct 89)
+@x module 411
+left_x(r):=x_coord(r);
+@y
+left_x(r):=x_coord(r);
+if right_x(p)>x_coord(r) then right_x(p):=x_coord(r);
+ {we always have |x_coord(p)<=right_x(p)|}
+@z
+@x ibid
+else if x_coord(r)>dest_x then x_coord(r):=dest_x;
+@y
+else begin if x_coord(r)>dest_x then
+    begin x_coord(r):=dest_x; left_x(r):=-x_coord(r); right_x(r):=x_coord(r);
+    end;
+  if left_x(q)>dest_x then left_x(q):=dest_x
+  else if left_x(q)<x_coord(r) then left_x(q):=x_coord(r);
+  end;
+@z
+@x module 412
+left_x(s):=x_coord(s);
+negate(x_coord(s)); right_x(s):=x_coord(s);
+negate(left_x(q));
+@y
+left_x(s):=x_coord(s); {now |x_coord(r)=right_x(r)<=left_x(s)|}
+if left_x(q)<dest_x then left_x(q):=-dest_x
+else if left_x(q)>x_coord(s) then left_x(q):=-x_coord(s)
+else negate(left_x(q));
+negate(x_coord(s)); right_x(s):=x_coord(s);
+@z
+@x module 415
+if x_coord(r)>dest_x then x_coord(r):=dest_x
+else if x_coord(r)<x_coord(pp) then x_coord(r):=x_coord(pp);
+if y_coord(r)<y_coord(pp) then y_coord(r):=y_coord(pp);
+left_y(r):=y_coord(r);
+@y
+if y_coord(r)<y_coord(pp) then y_coord(r):=y_coord(pp);
+left_y(r):=y_coord(r);
+if right_y(pp)>y_coord(r) then right_y(pp):=y_coord(r);
+ {we always have |y_coord(pp)<=right_y(pp)|}
+@z
+@x ibid
+else if y_coord(r)>dest_y then y_coord(r):=dest_y;
+@y
+else begin if y_coord(r)>dest_y then
+    begin y_coord(r):=dest_y; left_y(r):=-y_coord(r); right_y(r):=y_coord(r);
+    end;
+  if left_y(qq)>dest_y then left_y(qq):=dest_y
+  else if left_y(qq)<y_coord(r) then left_y(qq):=y_coord(r);
+  end;
+@z
+@x module 416
+if x_coord(s)>dest_x then x_coord(s):=dest_x
+else if x_coord(s)<x_coord(r) then x_coord(s):=x_coord(r);
+if y_coord(s)<dest_y then y_coord(s):=dest_y;
+if y_coord(s)<y_coord(r) then y_coord(s):=y_coord(r);
+right_type(s):=right_type(pp);
+left_y(s):=y_coord(s);
+negate(y_coord(s)); right_y(s):=y_coord(s);
+negate(left_y(qq));
+@y
+if y_coord(s)<dest_y then y_coord(s):=dest_y;
+if y_coord(s)<y_coord(r) then y_coord(s):=y_coord(r);
+right_type(s):=right_type(pp);
+left_y(s):=y_coord(s); {now |y_coord(r)=right_y(r)<=left_y(s)|}
+if left_y(qq)<dest_y then left_y(qq):=-dest_y
+else if left_y(qq)>y_coord(s) then left_y(qq):=-y_coord(s)
+else negate(left_y(qq));
+negate(y_coord(s)); right_y(s):=y_coord(s);
+@z
+@x module 424
+if y_coord(r)>dest_y then y_coord(r):=dest_y
+else if y_coord(r)<y_coord(p) then y_coord(r):=y_coord(p);
+if x_coord(r)<x_coord(p) then x_coord(r):=x_coord(p);
+left_x(r):=x_coord(r);@/
+y_coord(r):=y_coord(r)+x_coord(r); negate(x_coord(r));@/
+right_x(r):=x_coord(r); right_y(r):=right_y(r)-right_x(r);@/
+left_y(q):=left_y(q)+left_x(q); negate(left_x(q));@/
+dest_y:=dest_y+dest_x; negate(dest_x);
+@y
+if x_coord(p)+y_coord(r)>dest_x+dest_y then
+  begin y_coord(r):=dest_x+dest_y-x_coord(p);
+  if left_y(r)>y_coord(r) then
+    begin left_y(r):=y_coord(r);
+    if right_y(p)>y_coord(r) then right_y(p):=y_coord(r);
+    end;
+  end;
+if x_coord(r)<x_coord(p) then x_coord(r):=x_coord(p)
+else if x_coord(r)+y_coord(r)>dest_x+dest_y then
+  x_coord(r):=dest_x+dest_y-y_coord(r);
+left_x(r):=x_coord(r);
+if right_x(p)>x_coord(r) then right_x(p):=x_coord(r);
+ {we always have |x_coord(p)<=right_x(p)|}
+y_coord(r):=y_coord(r)+x_coord(r); right_y(r):=right_y(r)+x_coord(r);@/
+negate(x_coord(r)); right_x(r):=x_coord(r);@/
+left_y(q):=left_y(q)+left_x(q); negate(left_x(q));@/
+dest_y:=dest_y+dest_x; negate(dest_x);
+if right_y(r)>dest_y then right_y(r):=dest_y;
+if left_y(q)>dest_y then left_y(q):=dest_y
+else if left_y(q)<y_coord(r) then left_y(q):=y_coord(r);
+if right_y(r)>left_y(q) then right_y(r):=left_y(q);
+@z
+@x ibid
+else if x_coord(r)>dest_x then x_coord(r):=dest_x
+@y
+else begin if x_coord(r)>dest_x then
+    begin x_coord(r):=dest_x; left_x(r):=-x_coord(r); right_x(r):=x_coord(r);
+    end;
+  if left_x(q)>dest_x then left_x(q):=dest_x
+  else if left_x(q)<x_coord(r) then left_x(q):=x_coord(r);
+  end;
+@z
+@x module 425 is entirely replaced
+@y by the following code:
+@ @<Subdivide the cubic a second time with respect to $x'-y'$@>=
+begin split_cubic(r,t,dest_x,dest_y); s:=link(r);@/
+if x_coord(r)+y_coord(s)>dest_x+dest_y then
+  begin y_coord(s):=dest_x+dest_y-x_coord(r);
+  if left_y(s)>y_coord(s) then
+    begin left_y(s):=y_coord(s);
+    if right_y(r)>y_coord(s) then right_y(r):=y_coord(s);
+    end;
+  end;
+if x_coord(s)+y_coord(s)>dest_x+dest_y then x_coord(s):=dest_x+dest_y-y_coord(s)
+else begin if x_coord(s)<dest_x then x_coord(s):=dest_x;
+  if x_coord(s)<x_coord(r) then x_coord(s):=x_coord(r);
+  end;
+right_type(s):=right_type(p);
+left_x(s):=x_coord(s); {now |x_coord(r)=right_x(r)<=left_x(s)|}
+if left_x(q)<dest_x then
+  begin left_y(q):=left_y(q)+dest_x; left_x(q):=-dest_x;@+end
+else if left_x(q)>x_coord(s) then
+  begin left_y(q):=left_y(q)+x_coord(s); left_x(q):=-x_coord(s);@+end
+else begin left_y(q):=left_y(q)+left_x(q); negate(left_x(q));@+end;
+y_coord(s):=y_coord(s)+x_coord(s); right_y(s):=right_y(s)+x_coord(s);@/
+negate(x_coord(s)); right_x(s):=x_coord(s);@/
+dest_y:=dest_y+dest_x;
+if right_y(s)>dest_y then right_y(s):=dest_y;
+if left_y(q)>dest_y then left_y(q):=dest_y
+else if left_y(q)<y_coord(s) then left_y(q):=y_coord(s);
+if right_y(s)>left_y(q) then right_y(s):=left_y(q);
+end
+@z
+
+551. Major change for extended ligatures.
+@x module 11 (this may affect change files)
+@!lig_table_size=300; {maximum number of ligature/kern steps}
+@y
+@!lig_table_size=5000; {maximum number of ligature/kern steps, must be
+  at least 255 and at most 32510}
+@!max_kerns=500; {maximum number of distinct kern amounts}
+@z
+@x module 14 gets a new line of code
+@y
+if(lig_table_size<255)or(lig_table_size>32510)then bad:=7;
+@z
+@x module 186
+@d lig_kern_token=76 {the operators `\&{kern}' and `\.{=:}'}
+@d assignment=77 {the operator `\.{:=}'}
+@d colon=78 {the operator `\.:'}
+@#
+@d comma=79 {the operator `\.,'}
+@d end_of_statement==cur_cmd>comma
+@d semicolon=80 {the operator `\.;', must be |comma+1|}
+@d end_group=81 {end a group (\&{endgroup}), must be |semicolon+1|}
+@d stop=82 {end a job (\&{end}, \&{dump}), must be |end_group+1|}
+@y
+@d lig_kern_token=76
+  {the operators `\&{kern}' and `\.{=:}' and `\.{=:\char'174}, etc.}
+@d assignment=77 {the operator `\.{:=}'}
+@d skip_to=78 {the operation `\&{skipto}'}
+@d bchar_label=79 {the operator `\.{\char'174\char'174:}'}
+@d double_colon=80 {the operator `\.{::}'}
+@d colon=81 {the operator `\.:'}
+@#
+@d comma=82 {the operator `\.,', must be |colon+1|}
+@d end_of_statement==cur_cmd>comma
+@d semicolon=83 {the operator `\.;', must be |comma+1|}
+@d end_group=84 {end a group (\&{endgroup}), must be |semicolon+1|}
+@d stop=85 {end a job (\&{end}, \&{dump}), must be |end_group+1|}
+@z
+@x module 190
+@d max_given_internal=warning_check
+@y
+@d boundary_char=41 {the right boundary character for ligatures}
+@d max_given_internal=41
+@z
+@x module 192 gets two new lines of code
+@y
+primitive("boundarychar",internal_quantity,boundary_char);@/
+@!@:boundary_char_}{\&{boundarychar} primitive@>
+@z
+@x and module 193 gets one too
+@y
+int_name[boundary_char]:="boundarychar";
+@z
+@x and module 211 gets several
+@y (to be inserted in appropriate places)
+primitive("::",double_colon,0);
+@!@::: }{\.{::} primitive@>
+primitive("||:",bchar_label,0);
+@!@:::: }{\.{\char'174\char'174:} primitive@>
+primitive("skipto",skip_to,0);@/
+@!@:skip_to_}{\&{skipto} primitive@>
+@z
+@x as does module 212
+@y
+bchar_label:print("||:");
+double_colon:print("::");
+skip_to:print("skipto");
+@z
+@x module 1093 has new text (see TeX change 362 for module 545) and also this:
+@d stop_bit(#)==lig_kern[#].b0
+@d next_char(#)==lig_kern[#].b1
+@d op_bit(#)==lig_kern[#].b2
+@y
+@d skip_byte(#)==lig_kern[#].b0
+@d next_char(#)==lig_kern[#].b1
+@d op_byte(#)==lig_kern[#].b2
+@z
+@x module 1096 gets a new definition
+@y
+@d undefined_label==lig_table_size {an undefined local label}
+@z
+@x ...and some changed declarations
+@!char_remainder:array[eight_bits] of eight_bits; {the |remainder| byte}
+@!header_byte:array[1..header_size] of -1..255;
+  {bytes of the \.{TFM} header, or $-1$ if unset}
+@!lig_kern:array[0..lig_table_size] of four_quarters; {the ligature/kern table}
+@!nl:0..lig_table_size; {the number of ligature/kern steps so far}
+@!kern:array[eight_bits] of scaled; {distinct kerning amounts}
+@!nk:0..256; {the number of distinct kerns so far}
+@y
+@!char_remainder:array[eight_bits] of 0..lig_table_size; {the |remainder| byte}
+@!header_byte:array[1..header_size] of -1..255;
+  {bytes of the \.{TFM} header, or $-1$ if unset}
+@!lig_kern:array[0..lig_table_size] of four_quarters; {the ligature/kern table}
+@!nl:0..32767-256; {the number of ligature/kern steps so far}
+@!kern:array[0..max_kerns] of scaled; {distinct kerning amounts}
+@!nk:0..max_kerns; {the number of distinct kerns so far}
+@z
+@x ...and some new declarations
+@y
+@!skip_table:array[eight_bits] of 0..lig_table_size; {local label status}
+@!lk_started:boolean; {has there been a lig/kern step in this command yet?}
+@!bchar:integer; {right boundary character}
+@!bch_label:0..lig_table_size; {left boundary starting location}
+@!ll,@!lll:0..lig_table_size; {registers used for lig/kern processing}
+@!label_loc:array[0..256] of -1..lig_table_size; {lig/kern starting addresses}
+@!label_char:array[1..256] of eight_bits; {characters for |label_loc|}
+@!label_ptr:0..256; {highest position occupied in |label_loc|}
+@z
+@x module 1097
+  end;
+for k:=1 to header_size do header_byte[k]:=-1;
+bc:=255; ec:=0; nl:=0; nk:=0; ne:=0; np:=0;
+@y
+  skip_table[k]:=undefined_label;
+  end;
+for k:=1 to header_size do header_byte[k]:=-1;
+bc:=255; ec:=0; nl:=0; nk:=0; ne:=0; np:=0;@/
+internal[boundary_char]:=-unity;
+bch_label:=undefined_label;@/
+label_loc[0]:=-1; label_ptr:=0;
+@z
+@x module 1104
+procedure set_tag(@!c:eight_bits;@!t:small_number;@!r:eight_bits);
+begin if char_tag[c]=no_tag then
+  begin char_tag[c]:=t; char_remainder[c]:=r;
+@y
+procedure set_tag(@!c:halfword;@!t:small_number;@!r:halfword);
+begin if char_tag[c]=no_tag then
+  begin char_tag[c]:=t; char_remainder[c]:=r;
+  if t=lig_tag then
+    begin incr(label_ptr); label_loc[label_ptr]:=r; label_char[label_ptr]:=c;
+    end;
+@z
+@x module  1105
+if (c>" ")and(c<128) then print(c)
+@y
+if (c>" ")and(c<127) then print(c)
+else if c=256 then print("||")
+@z
+@x module 1106
+label continue;
+var @!c,@!cc:eight_bits; {character codes}
+@!k:0..256; {index into the |kern| array}
+@y
+label continue,done;
+var @!c,@!cc:0..256; {character codes}
+@!k:0..max_kerns; {index into the |kern| array}
+@z
+% also the previous code of module 1107 is inserted into 1106
+@x modules 1107--1111 are completely replaced
+@y by the following new code:
+@ @<Store a list of ligature/kern steps@>=
+begin lk_started:=false;
+continue: get_x_next;
+if(cur_cmd=skip_to)and lk_started then
+ @<Process a |skip_to| command and |goto done|@>;
+if cur_cmd=bchar_label then
+  begin c:=256; cur_cmd:=colon;@+end
+else begin back_input; c:=get_code;@+end;
+if(cur_cmd=colon)or(cur_cmd=double_colon)then
+  @<Record a label in a lig/kern subprogram and |goto continue|@>;
+if cur_cmd=lig_kern_token then @<Compile a ligature/kern command@>
+else  begin print_err("Illegal ligtable step");
+@.Illegal ligtable step@>
+  help1("I was looking for `=:' or `kern' here.");
+  back_error; next_char(nl):=qi(0); op_byte(nl):=qi(0); rem_byte(nl):=qi(0);@/
+  skip_byte(nl):=stop_flag+1; {this specifies an unconditional stop}
+  end;
+if nl=lig_table_size then overflow("ligtable size",lig_table_size);
+@:METAFONT capacity exceeded ligtable size}{\quad ligtable size@>
+incr(nl);
+if cur_cmd=comma then goto continue;
+if skip_byte(nl-1)<stop_flag then skip_byte(nl-1):=stop_flag;
+done:end
+
+@ @<Put each...@>=
+primitive("=:",lig_kern_token,0);
+@!@:=:_}{\.{=:} primitive@>
+primitive("=:|",lig_kern_token,1);
+@!@:=:/_}{\.{=:\char'174} primitive@>
+primitive("=:|>",lig_kern_token,5);
+@!@:=:/>_}{\.{=:\char'174>} primitive@>
+primitive("|=:",lig_kern_token,2);
+@!@:=:/_}{\.{\char'174=:} primitive@>
+primitive("|=:>",lig_kern_token,6);
+@!@:=:/>_}{\.{\char'174=:>} primitive@>
+primitive("|=:|",lig_kern_token,3);
+@!@:=:/_}{\.{\char'174=:\char'174} primitive@>
+primitive("|=:|>",lig_kern_token,7);
+@!@:=:/>_}{\.{\char'174=:\char'174>} primitive@>
+primitive("|=:|>>",lig_kern_token,11);
+@!@:=:/>_}{\.{\char'174=:\char'174>>} primitive@>
+primitive("kern",lig_kern_token,128);
+@!@:kern_}{\&{kern} primitive@>
+  
+@ @<Cases of |print_cmd...@>=
+lig_kern_token: case m of
+0:print("=:");
+1:print("=:|");
+2:print("|=:");
+3:print("|=:|");
+5:print("=:|>");
+6:print("|=:>");
+7:print("|=:|>");
+11:print("|=:|>>");
+othercases print("kern")
+endcases;
+  
+@ Local labels are implemented by maintaining the |skip_table| array,
+where |skip_table[c]| is either |undefined_label| or the address of the
+most recent lig/kern instruction that skips to local label~|c|. In the
+latter case, the |skip_byte| in that instruction will (temporarily)
+be zero if there were no prior skips to this label, or it will be the
+distance to the prior skip.
+
+We may need to cancel skips that span more than 127 lig/kern steps.
+
+@d cancel_skips(#)==ll:=#;
+  repeat lll:=qo(skip_byte(ll)); skip_byte(ll):=stop_flag; ll:=ll-lll;
+  until lll=0
+@d skip_error(#)==begin print_err("Too far to skip");
+@.Too far to skip@>
+  help1("At most 127 lig/kern steps can separate skipto1 from 1::.");
+  error; cancel_skips(#);
+  end
+
+@<Process a |skip_to| command and |goto done|@>=
+begin c:=get_code;
+if nl-skip_table[c]>128 then {|skip_table[c]<<nl<=undefined_label|}
+  begin skip_error(skip_table[c]); skip_table[c]:=undefined_label;
+  end;
+if skip_table[c]=undefined_label then skip_byte(nl-1):=qi(0)
+else skip_byte(nl-1):=qi(nl-skip_table[c]-1);
+skip_table[c]:=nl-1; goto done;
+end
+
+@ @<Record a label in a lig/kern subprogram and |goto continue|@>=
+begin if cur_cmd=colon then
+  if c=256 then bch_label:=nl
+  else set_tag(c,lig_tag,nl)
+else if skip_table[c]<undefined_label then
+  begin ll:=skip_table[c]; skip_table[c]:=undefined_label;
+  repeat lll:=qo(skip_byte(ll));
+  if nl-ll>128 then
+    begin skip_error(ll); goto continue;
+    end;
+  skip_byte(ll):=qi(nl-ll-1); ll:=ll-lll;
+  until lll=0;
+  end;
+goto continue;
+end
+@x module 1112
+next_char(nl):=qi(c); op_bit(nl):=qi(cur_mod); stop_bit(nl):=qi(0);
+if cur_mod=0 then rem_byte(nl):=qi(get_code)
+@y
+begin next_char(nl):=qi(c); skip_byte(nl):=qi(0);
+if cur_mod<128 then {ligature op}
+  begin op_byte(nl):=qi(cur_mod); rem_byte(nl):=qi(get_code);
+  end
+@z
+@x ibid
+    begin if nk=256 then overflow("kern",256);
+@:METAFONT capacity exceeded kern}{\quad kern@>
+    incr(nk);
+    end;
+  rem_byte(nl):=qi(k);
+  end
+@y
+    begin if nk=max_kerns then overflow("kern",max_kerns);
+@:METAFONT capacity exceeded kern}{\quad kern@>
+    incr(nk);
+    end;
+  op_byte(nl):=kern_flag+(k div 256);
+  rem_byte(nl):=qi((k mod 256));
+  end;
+lk_started:=true;
+end
+@z
+@x module 1135
+tfm_two(6+lh+(ec-bc+1)+nw+nh+nd+ni+nl+nk+ne+np);
+  {this is the total number of file words that will be output}
+tfm_two(lh); tfm_two(bc); tfm_two(ec); tfm_two(nw); tfm_two(nh);
+tfm_two(nd); tfm_two(ni); tfm_two(nl); tfm_two(nk); tfm_two(ne); tfm_two(np);
+@y
+@<Compute the ligature/kern program offset and implant the
+  left boundary label@>;
+tfm_two(6+lh+(ec-bc+1)+nw+nh+nd+ni+nl+lk_offset+nk+ne+np);
+  {this is the total number of file words that will be output}
+tfm_two(lh); tfm_two(bc); tfm_two(ec); tfm_two(nw); tfm_two(nh);
+tfm_two(nd); tfm_two(ni); tfm_two(nl+lk_offset); tfm_two(nk); tfm_two(ne);
+tfm_two(np);
+@z
+% modules 1137&1138 are combined into a single module
+% and so are modules 1140--1141, to make room for two new modules.
+@x module 1136 is moved to after old module 1141
+@y and changed to the following code:
+@ @<Log the subfile sizes of the \.{TFM} file@>=
+if bch_label<undefined_label then decr(nl);
+wlog_ln('(You used ',nw:1,'w,',@| nh:1,'h,',@| nd:1,'d,',@| ni:1,'i,',@|
+ nl:1,'l,',@| nk:1,'k,',@| ne:1,'e,',@|
+ np:1,'p metric file positions');
+wlog_ln('  out of ',@| '256w,16h,16d,64i,',@|
+ lig_table_size:1,'l,',max_kerns:1,'k,256e,',@|
+ max_font_dimen:1,'p)');
+end
+@z
+@x module 1139 is completely replaced
+@y by the following three modules:
+@ We need to output special instructions at the beginning of the
+|lig_kern| array in order to specify the right boundary character
+and/or to handle starting addresses that exceed 255. The |label_loc|
+and |label_char| arrays have been set up to record all the
+starting addesses; we have $-1=|label_loc|[0]<|label_loc|[1]\le\cdots
+\le|label_loc|[|label_ptr]|$.
+
+@<Compute the ligature/kern program offset...@>=
+bchar:=round_unscaled(internal[boundary_char]);
+if(bchar<0)or(bchar>255)then
+  begin bchar:=-1; lk_started:=false; lk_offset:=0;@+end
+else begin lk_started:=true; lk_offset:=1;@+end;
+@<Find the minimum |lk_offset| and adjust all remainders@>;
+if bch_label<undefined_label then
+  begin skip_byte(nl):=qi(255); next_char(nl):=qi(0);
+  op_byte(nl):=qi(((bch_label+lk_offset)div 256));
+  rem_byte(nl):=qi(((bch_label+lk_offset)mod 256));
+  incr(nl); {possibly |nl=lig_table_size+1|}
+  end
+
+@ @<Find the minimum |lk_offset|...@>=
+k:=label_ptr; {pointer to the largest unallocated label}
+if label_loc[k]+lk_offset>255 then
+  begin lk_offset:=0; lk_started:=false; {location 0 can do double duty}
+  repeat char_remainder[label_char[k]]:=lk_offset;
+  while label_loc[k-1]=label_loc[k] do
+    begin decr(k); char_remainder[label_char[k]]:=lk_offset;
+    end;
+  incr(lk_offset); decr(k);
+  until lk_offset+label_loc[k]<256;
+    {N.B.: |lk_offset=256| satisfies this when |k=0|}
+  end;
+if lk_offset>0 then
+  while k>0 do
+    begin char_remainder[label_char[k]]
+     :=char_remainder[label_char[k]]+lk_offset;
+    decr(k);
+    end
+
+@ @<Output the ligature/kern program@>=
+for k:=0 to 255 do if skip_table[k]<undefined_label then
+  begin print_nl("(local label "); print_int(k); print(":: was missing)");
+@.local label l:: was missing@>
+  cancel_skips(skip_table[k]);
+  end;
+if lk_started then {|lk_offset=1| for the special |bchar|}
+  begin tfm_out(255); tfm_out(bchar); tfm_two(0);
+  end
+else for k:=1 to lk_offset do {output the redirection specs}
+  begin ll:=label_loc[label_ptr];
+  if bchar<0 then
+    begin tfm_out(254); tfm_out(0);
+    end
+  else begin tfm_out(255); tfm_out(bchar);
+    end;
+  tfm_two(ll+lk_offset);
+  repeat decr(label_ptr);
+  until label_loc[label_ptr]<ll;
+  end;
+for k:=0 to nl-1 do tfm_qqqq(lig_kern[k]);
+for k:=0 to nk-1 do tfm_four(dimen_out(kern[k]))
+@z
+@x module 1205 gets a new declaration
+@y
+@!lk_offset:0..256; {extra words inserted at beginning of |lig_kern| array}
+@z
+
+552. Improved the covering/shortening routines. (18 Dec 89)
+@x module 1119 gets a new global variable
+@y
+@!excess:integer; {the list is this much too long}
+@z
+@x module 1120 gives it a value
+begin if min_cover(0)<=m then threshold:=0
+@y
+begin excess:=min_cover(0)-m;
+if excess<=0 then threshold:=0
+@z
+@x and module 1122 uses it
+begin repeat p:=link(p); info(p):=m;
+@y
+begin repeat p:=link(p); info(p):=m;
+decr(excess);@+if excess=0 then d:=0;
+@z
+@x and module 1122 also avoids overflow/ambiguous halving
+v:=half(l+value(p));
+@y
+v:=l+half(value(p)-l);
+@z
+
+553. Global variable used prematurely in do_add_to (Alan Jeffrey, 9 Feb 90)
+@x module 403
+@!cur_path_type:double_path_code..also_code; {likewise}
+@y
+@!cur_path_type:double_path_code..contour_code; {likewise}
+@z
+@x module 1059
+begin get_x_next; var_flag:=thing_to_add; scan_primary;
+if cur_type<>token_list then
+  @<Abandon edges command because there's no variable@>
+else  begin lhs:=cur_exp; cur_path_type:=cur_mod;@/
+  cur_type:=vacuous; get_x_next; scan_expression;
+  if cur_path_type=also_code then @<Augment some edges by others@>
+@y
+@!add_to_type:double_path_code..also_code; {modifier of \&{addto}}
+begin get_x_next; var_flag:=thing_to_add; scan_primary;
+if cur_type<>token_list then
+  @<Abandon edges command because there's no variable@>
+else  begin lhs:=cur_exp; add_to_type:=cur_mod;@/
+  cur_type:=vacuous; get_x_next; scan_expression;
+  if add_to_type=also_code then @<Augment some edges by others@>
+@z
+@x module 1064
+else  begin lhs:=null;
+@y
+else  begin lhs:=null; cur_path_type:=add_to_type;
+@z
+
+554. Balance the parens showing on the terminal (for Lispers).
+@x module 631
+@!in_open : 0..max_in_open; {the number of lines in the buffer, less one}
+@y
+@!in_open : 0..max_in_open; {the number of lines in the buffer, less one}
+@!open_parens : 0..max_in_open; {the number of open text files}
+@z
+@x module 657
+in_open:=0; max_buf_stack:=0;
+@y
+in_open:=0; open_parens:=0; max_buf_stack:=0;
+@z
+@x module 681
+  begin print_char(")"); force_eof:=false;
+  update_terminal; {show user that file has been read}
+@y
+  begin print_char(")"); decr(open_parens);
+  update_terminal; {show user that file has been read}
+  force_eof:=false;
+@z
+@x module 793
+print_char("("); print(name); update_terminal;
+@y
+print_char("("); incr(open_parens); print(name); update_terminal;
+@z
+@x module 1209
+if job_name=0 then open_log_file;
+@y
+if job_name=0 then open_log_file;
+while open_parens>0 do
+  begin print(" )"); decr(open_parens);
+  end;
+@z
+
+-----------Here I draw the line with respect to further changes
+
+555. Don't try system area if an area was given (see tex82.bug number 312;
+found by Jonathan Kew, May 1990)
+@x module 793
+  pack_file_name(cur_name,MF_area,cur_ext);
+  if a_open_in(cur_file) then goto done;
+@y
+  if cur_area="" then
+    begin pack_file_name(cur_name,MF_area,cur_ext);
+    if a_open_in(cur_file) then goto done;
+    end;
+@z
+
+556. Report correct line number when buffer overflows (CET, Jul 90).
+@x module 794
+begin if not input_ln(cur_file,false) then do_nothing;
+firm_up_the_line;
+buffer[limit]:="%"; first:=limit+1; loc:=start; line:=1;
+@y
+begin line:=1;
+if input_ln(cur_file,false) then do_nothing;
+firm_up_the_line;
+buffer[limit]:="%"; first:=limit+1; loc:=start;
+@z
+
+557. TeX82 bug 308, corrected in 1985, is also in MF! (Lutz Birkhahn, May91)
+@x module 176
+var_used:=lo_mem_stat_max+1-mem_min; dyn_used:=mem_top+1-hi_mem_stat_min;
+@y
+var_used:=lo_mem_stat_max+1-mem_min; dyn_used:=mem_top+1-hi_mem_min;
+@z
+
+558. Allow unprintable file names, as in TeX change 396 (19 Sep 91)
+(Much of this is redundant except for people who make nonportable
+versions that allow other 8-bit codes to be in variable names---and for
+those people only if they allow input of more codes than they can print!
+Still, it seems best to make the programs for TeX and MF as alike as possible.)
+@x module 59
+j:=str_start[s];
+while j<str_start[s+1] do
+  begin print_char(so(str_pool[j])); incr(j);
+  end;
+@y
+if (s<256)and(selector>pseudo) then print_char(s)
+else begin j:=str_start[s];
+  while j<str_start[s+1] do
+    begin print_char(so(str_pool[j])); incr(j);
+    end;
+  end;
+@z
+@x module 60
+j:=str_start[s];
+while j<str_start[s+1] do
+  begin print(so(str_pool[j])); incr(j);
+  end;
+@y
+if (s<256)and(selector>pseudo) then print_char(s)
+else begin j:=str_start[s];
+  while j<str_start[s+1] do
+    begin print(so(str_pool[j])); incr(j);
+    end;
+  end;
+@z
+@x module 61
+else  begin print(base_ident); print_ln;
+@y
+else  begin slow_print(base_ident); print_ln;
+@z
+@x module 79
+  print(input_stack[file_ptr].name_field);
+@y
+  slow_print(input_stack[file_ptr].name_field);
+@z
+@x module 223
+print(r);
+@y
+slow_print(r);
+@z
+@x module 254
+      print(int_name[q-(hash_end)]); print_char("=");
+@y
+      slow_print(int_name[q-(hash_end)]); print_char("=");
+@z
+@x module 254 again
+      print(text(q)); print_char("}");
+@y
+      slow_print(text(q)); print_char("}");
+@z
+@x module 638
+  if name<>null then print(text(name))
+@y
+  if name<>null then slow_print(text(name))
+@z
+@x module 664
+  if scanner_status=op_defining then print(text(warning_info))
+@y
+  if scanner_status=op_defining then slow_print(text(warning_info))
+@z
+@x module 664 again
+loop_defining: begin print("the text of a "); print(text(warning_info));
+@y
+loop_defining: begin print("the text of a "); slow_print(text(warning_info));
+@z
+@x module 722
+begin if n<>null then print(text(n))
+@y
+begin if n<>null then slow_print(text(n))
+@z
+@x module 722 again
+  if p=null then print(text(info(info(link(a)))))
+@y
+  if p=null then slow_print(text(info(info(link(a)))))
+@z
+@x module 725
+  print_nl("  Missing `"); print(text(r_delim));
+@y
+  print_nl("  Missing `"); slow_print(text(r_delim));
+@z
+@x module 773
+begin print(a); print(n); print(e);
+@y
+begin slow_print(a); slow_print(n); slow_print(e);
+@z
+@x module 790
+print(base_ident); print("  ");
+@y
+slow_print(base_ident); print("  ");
+@z
+@x module 793
+print_char("("); incr(open_parens); print(name); update_terminal;
+@y
+print_char("("); incr(open_parens); slow_print(name); update_terminal;
+@z
+@x module 998
+if info(lhs)>hash_end then print(int_name[info(lhs)-(hash_end)])
+@y
+if info(lhs)>hash_end then slow_print(int_name[info(lhs)-(hash_end)])
+@z
+@x module 999
+  print(int_name[info(lhs)-(hash_end)]);
+@y
+  slow_print(int_name[info(lhs)-(hash_end)]);
+@z
+@x module 1032
+else  begin print_err("The token `"); print(text(r_delim));
+@y
+else  begin print_err("The token `"); slow_print(text(r_delim));
+@z
+@x module 1034
+  else print(text(cur_sym));
+@y
+  else slow_print(text(cur_sym));
+@z
+@x module 1041
+else  begin print(text(cur_sym)); print_char("=");
+@y
+else  begin slow_print(text(cur_sym)); print_char("=");
+@z
+@x module 1042
+else  begin print_char(""""); print(cur_mod); print_char("""");
+@y
+else  begin print_char(""""); slow_print(cur_mod); print_char("""");
+@z
+@x module 1043
+  print("t delimiter that matches "); print(text(m));
+@y
+  print("t delimiter that matches "); slow_print(text(m));
+@z
+@x module 1043 again
+internal_quantity:print(int_name[m]);
+@y
+internal_quantity:slow_print(int_name[m]);
+@z
+@x module 1134
+print_nl("Font metrics written on "); print(metric_file_name); print_char(".");
+@y
+print_nl("Font metrics written on "); slow_print(metric_file_name);
+print_char(".");
+@z
+@x module 1182
+print_nl("Output written on "); print(output_file_name);
+@y
+print_nl("Output written on "); slow_print(output_file_name);
+@z
+@x module 1200
+print(w_make_name_string(base_file)); flush_string(str_ptr-1);
+print_nl(base_ident)
+@y
+slow_print(w_make_name_string(base_file)); flush_string(str_ptr-1);
+print_nl(""); slow_print(base_ident)
+@z
+@x module 1205
+    print(log_name); print_char(".");
+@y
+    slow_print(log_name); print_char(".");
+@z
+@x module 1213
+10: print(n);
+@y
+10: slow_print(n);
+@z
+
+------ The third printing of Volume D (October 1991) incorporated the above.
+
+559. Debugging routine never used since change 528; needed update then (JDH).
+@x module 617
+  p:=dep_list(p); r:=hi_mem_min;
+  repeat if info(p)>=r then
+@y
+  p:=dep_list(p); r:=inf_val;
+  repeat if value(info(p))>=value(r) then
+@z
+
+560. Corrections to blunders in change 550 (noted by B Jackowski, Jul 91).
+@x module 415 can use more paranoia even though no problems have occurred yet
+negate(left_y(qq)); negate(dest_y);@/
+@y
+negate(left_y(qq)); negate(dest_y);@/
+if x_coord(r)<x_coord(pp) then x_coord(r):=x_coord(pp)
+else if x_coord(r)>dest_x then x_coord(r):=dest_x;
+if left_x(r)>x_coord(r) then
+  begin left_x(r):=x_coord(r);
+  if right_x(pp)>x_coord(r) then right_x(pp):=x_coord(r);
+  end;
+if right_x(r)<x_coord(r) then
+  begin right_x(r):=x_coord(r);
+  if left_x(qq)<x_coord(r) then left_x(qq):=x_coord(r);
+  end;
+@z
+@x module 416 similarly
+negate(y_coord(s)); right_y(s):=y_coord(s);
+@y
+negate(y_coord(s)); right_y(s):=y_coord(s);
+if x_coord(s)<x_coord(r) then x_coord(s):=x_coord(r)
+else if x_coord(s)>dest_x then x_coord(s):=dest_x;
+if left_x(s)>x_coord(s) then
+  begin left_x(s):=x_coord(s);
+  if right_x(r)>x_coord(s) then right_x(r):=x_coord(s);
+  end;
+if right_x(s)<x_coord(s) then
+  begin right_x(s):=x_coord(s);
+  if left_x(qq)<x_coord(s) then left_x(qq):=x_coord(s);
+  end;
+@z
+@x module 424 similarly
+if x_coord(p)+y_coord(r)>dest_x+dest_y then
+  begin y_coord(r):=dest_x+dest_y-x_coord(p);
+  if left_y(r)>y_coord(r) then
+    begin left_y(r):=y_coord(r);
+    if right_y(p)>y_coord(r) then right_y(p):=y_coord(r);
+    end;
+  end;
+@y
+if y_coord(r)<y_coord(p) then y_coord(r):=y_coord(p)
+else if y_coord(r)>dest_y then y_coord(r):=dest_y;
+if x_coord(p)+y_coord(r)>dest_x+dest_y then
+  y_coord(r):=dest_x+dest_y-x_coord(p);
+if left_y(r)>y_coord(r) then
+  begin left_y(r):=y_coord(r);
+  if right_y(p)>y_coord(r) then right_y(p):=y_coord(r);
+  end;
+if right_y(r)<y_coord(r) then
+  begin right_y(r):=y_coord(r);
+  if left_y(q)<y_coord(r) then left_y(q):=y_coord(r);
+  end;
+@z
+@x in module 424, here's the serious bug introduced in change #550.
+if right_y(r)>dest_y then right_y(r):=dest_y;
+if left_y(q)>dest_y then left_y(q):=dest_y
+else if left_y(q)<y_coord(r) then left_y(q):=y_coord(r);
+if right_y(r)>left_y(q) then right_y(r):=left_y(q);
+@y
+if right_y(r)<y_coord(r) then
+  begin right_y(r):=y_coord(r);
+  if left_y(q)<y_coord(r) then left_y(q):=y_coord(r);
+  end;
+@z
+@x module 425 is analogous
+if x_coord(r)+y_coord(s)>dest_x+dest_y then
+  begin y_coord(s):=dest_x+dest_y-x_coord(r);
+  if left_y(s)>y_coord(s) then
+    begin left_y(s):=y_coord(s);
+    if right_y(r)>y_coord(s) then right_y(r):=y_coord(s);
+    end;
+  end;
+@y
+if y_coord(s)<y_coord(r) then y_coord(s):=y_coord(r)
+else if y_coord(s)>dest_y then y_coord(s):=dest_y;
+if x_coord(r)+y_coord(s)>dest_x+dest_y then
+  y_coord(s):=dest_x+dest_y-x_coord(r);
+if left_y(s)>y_coord(s) then
+  begin left_y(s):=y_coord(s);
+  if right_y(r)>y_coord(s) then right_y(r):=y_coord(s);
+  end;
+if right_y(s)<y_coord(s) then
+  begin right_y(s):=y_coord(s);
+  if left_y(q)<y_coord(s) then left_y(q):=y_coord(s);
+  end;
+@z
+@x module 425, the analogous bug
+dest_y:=dest_y+dest_x;
+if right_y(s)>dest_y then right_y(s):=dest_y;
+if left_y(q)>dest_y then left_y(q):=dest_y
+else if left_y(q)<y_coord(s) then left_y(q):=y_coord(s);
+if right_y(s)>left_y(q) then right_y(s):=left_y(q);
+@y
+if right_y(s)<y_coord(s) then
+  begin right_y(s):=y_coord(s);
+  if left_y(q)<y_coord(s) then left_y(q):=y_coord(s);
+  end;
+@z
+
+561. serious longstanding bug caused overflows and bad rounding (1 Mar 95)
+@x module 815
+begin if (max_c[dependent]>=fraction_one)or@|
+ (max_c[dependent] div @'10000 >= max_c[proto_dependent]) then
+@y
+begin if (max_c[dependent] div @'10000 >=
+          max_c[proto_dependent]) then
+@z
+
+562. final cleanup should not retain spurious reference counts (20 Mar 95)
+@x module 1209
+while open_parens>0 do
+@y
+while input_ptr>0 do
+  if token_state then end_token_list@+else end_file_reading;
+while loop_ptr<>null do stop_iteration;
+while open_parens>0 do
+@z
+@x module 1209
+  cur_if:=name_type(cond_ptr); cond_ptr:=link(cond_ptr);
+@y
+  cur_if:=name_type(cond_ptr); loop_ptr:=cond_ptr;
+  cond_ptr:=link(cond_ptr); free_node(loop_ptr,if_node_size);
+@z
+
+563. unprintable strings of length 1 need to be truly length 1 (27 Nov 95,
+pointed out by Ulrik Vieth)
+@x module 671
+  if loc=k+1 then cur_mod:=buffer[k]
+@y
+  if (loc=k+1) and (length(buffer[k])=1) then cur_mod:=buffer[k]
+@z
+
+564. minor improvement to pythagorean addition (22 Jan 97)
+@x module 124
+if a>0 then
+@y
+if b>0 then
+@z
+
+565. we need not raise hackles about two-digit years (23 Nov 98)
+@x module 1200
+print_int(round_unscaled(internal[year]) mod 100); print_char(".");
+@y
+print_int(round_unscaled(internal[year])); print_char(".");
+@z
+
+566. "this can't happen" can happen if coordinates are half vast
+ (Julian Gilbey, January 2001)
+@x module 402
+@!chopped:boolean; {have we truncated any of the data?}
+@y
+@!chopped:integer; {positive if data truncated,
+          negative if data dangerously large}
+@z
+@x module 402
+if internal[autorounding]>0 then xy_round;
+octant_subdivide; {complete the subdivision}
+if internal[autorounding]>unity then diag_round;
+@<Remove dead cubics@>;
+@<Insert octant boundaries and compute the turning number@>;
+while left_type(cur_spec)<>endpoint do cur_spec:=link(cur_spec);
+if tracing>0 then
+  if internal[autorounding]<=0 then print_spec(", after subdivision")
+@y
+if (internal[autorounding]>0)and(chopped=0) then xy_round;
+octant_subdivide; {complete the subdivision}
+if (internal[autorounding]>unity)and(chopped=0) then diag_round;
+@<Remove dead cubics@>;
+@<Insert octant boundaries and compute the turning number@>;
+while left_type(cur_spec)<>endpoint do cur_spec:=link(cur_spec);
+if tracing>0 then
+  if (internal[autorounding]<=0)or(chopped<>0) then
+    print_spec(", after subdivision")
+@z
+@x module 404
+@d procrustes(#)==if abs(#)>max_allowed then
+    begin chopped:=true;
+    if #>0 then #:=max_allowed@+else #:=-max_allowed;
+    end
+
+@<Truncate the values of all coordinates that exceed...@>=
+p:=cur_spec; k:=1; chopped:=false;
+@y
+@d procrustes(#)==if abs(#)>=dmax then
+  if abs(#)>max_allowed then
+    begin chopped:=1;
+    if #>0 then #:=max_allowed@+else #:=-max_allowed;
+    end
+  else if chopped=0 then chopped:=-1
+
+@<Truncate the values of all coordinates that exceed...@>=
+p:=cur_spec; k:=1; chopped:=0; dmax:=half(max_allowed);
+@z
+@x module 404
+if chopped then
+@y
+if chopped>0 then
+@z
+
+567. I forgot to update curtype in e.g. boolean b[]; b1=true=b2;
+ (Thorsten Dahlheimer, June 2004)
+@x 1003
+    begin nonlinear_eq(v,cur_exp,false); goto done;
+@y
+    begin nonlinear_eq(v,cur_exp,false); unstash_cur_exp(cur_exp); goto done;
+@z
+
+568. Wrong handling of extreme TFM values (T. Dahlheimer, June 2004)
+@x 1128
+max_tfm_dimen:=16*internal[design_size]-internal[design_size] div @'10000000;
+@y
+max_tfm_dimen:=16*internal[design_size]-1-internal[design_size] div @'10000000;
+@z
+@x 1129
+  if x>0 then x:=three_bytes-1@+else x:=1-three_bytes;
+  end
+else x:=make_scaled(x*16,internal[design_size]);
+@y
+  if x>0 then x:=max_tfm_param@+else x:=-max_tfm_param;
+  end;
+x:=make_scaled(x*16,internal[design_size]);
+@z
+
+569. Bug in make_ellipse when theta=180 (T. Dahlheimer, June 2004)
+@x 530
+  else  begin beta:=minor_axis; gamma:=major_axis;
+@y
+  else  begin beta:=minor_axis; gamma:=major_axis; theta:=0;
+@z
+
+570. Forgot outer_tag in scan_declared variable (T. Dahlheimer, June 2004)
+@x 1011
+done: if eq_type(x)<>tag_token then clear_symbol(x,false);
+@y
+done: if eq_type(x) mod outer_tag<>tag_token then clear_symbol(x,false);
+@z
+
+571. Apparent bug if init_gf called at incredibly unlikely time (T. Dahlheimer,
+June 2004); not REALLY a bug, because str_ptr cannot equal max_strings here
+(because this was checked by end_name, and area_delimiter=0 there because
+cur_area="" in the output file name); but anyway I'll make a patch to be clean
+@x 1163
+str_start[str_ptr+1]:=pool_ptr; gf_string(0,str_ptr);
+@y
+gf_string(0,make_string); decr(str_ptr);
+@z
+
+572. Memory leak in make_ellipse on symmetric pens that don't have
+a point on the x-axis (Eberhard Mattes, 03 June 2008)
+@x module 536
+done1: link(p):=s; beta:=-y_coord(h);
+@y
+done1: if (link(p)<>null) then free_node(link(p),knot_node_size);
+link(p):=s; beta:=-y_coord(h);
+@z
+
+573. Don't restrict the length of the banner line, leave it system-dependent code
+(Udo Wermuth, 02 April 2017)
+@x module 61
+incorrect, but the discrepancy is not serious since we assume that the banner
+and base identifier together will occupy at most |max_print_line|
+character positions.
+@y
+incorrect, but the discrepancy is not serious since we assume that this
+part of the program is system dependent.
+@^system dependencies@>
+@z
+
+574. Defeat interactions during batch mode (Xiaosa Zhang, 27 June 2020)
+@x module 78
+@ @<Get user's advice...@>=
+loop@+begin continue: clear_for_error_prompt; prompt_input("? ");
+@y
+@ @<Get user's advice...@>=
+loop@+begin continue: if interaction<>error_stop_mode then return;
+  clear_for_error_prompt; prompt_input("? ");
+@z
+
+575. Don't exit to editor if no input file is at the bottom line
+(Xiaosa Zhang, 03 July 2020)
+@x module 79
+"E": if file_ptr>0 then
+@y
+"E": if file_ptr>0 then if input_stack[file_ptr].name_field>=256 then
+@z
+@x module 80
+if file_ptr>0 then print("E to edit your file,");
+@y
+if file_ptr>0 then if input_stack[file_ptr].name_field>=256 then
+  print("E to edit your file,");
+@z
+
+576. Keep date and time in system variables, use them in opening banner
+(Udo Wermuth, 11 December 2020)
+@x module 194
+Since standard \PASCAL\ cannot provide such information, something special
+is needed. The program here simply specifies July 4, 1776, at noon; but
+users probably want a better approximation to the truth.
+
+Note that the values are |scaled| integers. Hence \MF\ can no longer
+be used after the year 32767.
+
+@p procedure fix_date_and_time;
+begin internal[time]:=12*60*unity; {minutes since midnight}
+internal[day]:=4*unity; {fourth day of the month}
+internal[month]:=7*unity; {seventh month of the year}
+internal[year]:=1776*unity; {Anno Domini}
+end;
+@y
+Since standard \PASCAL\ cannot provide such information, something special
+is needed. The program here simply assumes that suitable values appear in
+the global variables \\{sys\_time}, \\{sys\_day}, \\{sys\_month}, and
+\\{sys\_year} (which are initialized to noon on 4 July 1776,
+in case the implementor is careless).
+
+Note that the values are |scaled| integers. Hence \MF\ can no longer
+be used after the year 32767.
+
+@p procedure fix_date_and_time;
+begin sys_time:=12*60;
+sys_day:=4; sys_month:=7; sys_year:=1776;  {self-evident truths}
+internal[time]:=sys_time*unity; {minutes since midnight}
+internal[day]:=sys_day*unity; {day of the month}
+internal[month]:=sys_month*unity; {month of the year}
+internal[year]:=sys_year*unity; {Anno Domini}
+end;
+@z
+@x module 196
+@ Of course we had better declare another global variable, if the previous
+routines are going to work.
+
+@<Glob...@>=
+@!old_setting:0..max_selector;
+@y  
+@ Of course we had better declare a few more global variables, if the previous
+routines are going to work.
+
+@<Glob...@>=
+@!old_setting:0..max_selector;
+@!sys_time,@!sys_day,@!sys_month,@!sys_year:integer;
+    {date and time supplied by external system}
+@z
+@x module 790
+print_int(round_unscaled(internal[day])); print_char(" ");
+months:='JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC';
+m:=round_unscaled(internal[month]);
+for k:=3*m-2 to 3*m do wlog(months[k]);
+print_char(" "); print_int(round_unscaled(internal[year])); print_char(" ");
+m:=round_unscaled(internal[time]);
+print_dd(m div 60); print_char(":"); print_dd(m mod 60);
+@y
+print_int(sys_day); print_char(" ");
+months:='JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC';
+for k:=3*sys_month-2 to 3*sys_month do wlog(months[k]);
+print_char(" "); print_int(sys_year); print_char(" ");
+print_dd(sys_time div 60); print_char(":"); print_dd(sys_time mod 60);
+@z
+@x module 1211
+fix_date_and_time; init_randoms((internal[time] div unity)+internal[day]);@/
+@y
+fix_date_and_time; init_randoms(sys_time+sys_day*unity);@/
+@z
+
+-------------
+999. The absolutely final change (to be made after my death)
+@x module 2
+@d banner=='This is METAFONT, Version 2.71828182' {printed when \MF\ starts}
+@y
+@d banner=='This is METAFONT, Version $e$' {printed when \MF\ starts}
+@z
+When this change is made, the corresponding line should be changed in
+Volume D, and also on page 31 of The METAFONTbook.
+My last will and testament for METAFONT is that no further changes be made
+under any circumstances. Improved systems should not be called simply
+`METAFONT'; that name, unqualified, should refer only to the program for which
+I have taken personal responsibility.  -- Don Knuth
diff --git a/Master/texmf-dist/doc/generic/knuth-errata/tex82.bug b/Master/texmf-dist/doc/generic/knuth-errata/tex82.bug
new file mode 100644
index 00000000000..12de105bae8
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/knuth-errata/tex82.bug
@@ -0,0 +1,9279 @@
+This file has been updated periodically ever since TeX82 was born;
+it has been summarized in "The errors of TeX," Software Practice &
+Experience, July 1989. Entries are in chronological order;
+thus the most recent news (including all bugfixes made since
+that article was published) appears at the bottom of the file.
+
+[Add 519 to these entry numbers to get the corresponding number in
+the published article. The article also translates all module
+numbers to their final form; what you are about to read is
+"authentic source material" from the early days before TeX converged.]
+
+-------------------------------------------------------------------------------
+
+First updates to the TeX82 listing published in September, 1982.
+(These changes were included in the original Version 0 of TeX, but they
+were discovered after the listing went to press.)
+
+1. Module 943, line 6 (bug discovered 9/28)
+change "if cur_cmd=char_num then" to
+        if (cur_cmd=letter) or (cur_cmd=other_char) then r:=qi(cur_chr)
+        else if cur_cmd=char_num then
+
+2. "pause" changed to "pausing" and "pause_code" to "pausing code", throughout.
+
+3. Module 719, lines 8 and 11 (bug discovered 9/28)
+insert "rule_save:=overfull_rule; overfull_rule:=0;" after "save_ptr-2;"
+insert "overfull_rule:=rule_save;" before "q:=p+list_offset;"
+and insert a declaration of "overfull_rule: scaled" in module 716.
+
+4. Module 1128, lines 6 and following (bug discovered 9/28)
+change "while n<>0 do" to "loop"
+change "goto done" to
+        begin scan_left_brace; new_save_level(false_group);
+        goto done;
+        end
+change "... return 1130>;" to
+                ... return 1130>
+        else if n=0 then
+                begin new_save_level(case_group); goto done;
+                end;
+and change "done: ... (false_group);" to "done:".
+
+5. Module 182, line 10 (suggestion by DRF on 9/30)
+change "0.0" to "?.?"
+
+6. Module 682, new definition of math_spacing (decision of 10/2)
+"0234000122*4000133**3**344*0400400*000000234000111*4111112341011"
+
+7. Module 684, new code for case "4" (decision of 10/2)
+"4": if cur_style<script_style then x:=thick_mu_skip_code else x:=0;
+[Also in module 682 line 7, say "...a conditional thick space (\nonscript..."]
+
+8. Module 11, trie_size changed from 7000 to 8000 because of new
+improved (but longer) hyphenation patterns (10/4)
+
+9. Module 453, forgot to change this when 454 changed (noted by DRF 10/6)
+format_default_length=20 (not 22)
+format_area_length=11 (not 13)
+
+Changes to TEX.WEB made after Version 0 was released in October, 1982.
+
+Since copies of TEX.WEB are not supposed to be edited, there are
+two ways to make your version of TeX bug-free:
+        1. Get a new copy of TEX.WEB.
+        2. Put the corrections into your change file(s).
+Some people will find (1) easier than (2), except the main TeX sources at
+SCORE won't be updated quite as fast as the sources at SAIL (which have to
+be translated into ascii before they are sent to the outside world).
+Actually (2) will be quite easy, unless the list of changes becomes quite
+long, so it is the recommended procedure. In case (2) it would be useful
+to include a comment like "this is fix number xx" (using the numbering
+scheme in this file), so that the change could readily be deleted at some
+future time.
+
+10. Module 857 line -5 (bug discovered 10/8/82 by HWT)
+change it to: if h>0 then decr(h) else h:=trie_op_hash_size;
+
+11. Module 457 line 3 (typo discovered 10/9/82)
+change `\.!' to `\.\&'
+
+12. Module 1245 line 8 (bug fixed 10/9/82, discovered by MMD)
+insert the following between "begin" and "if":
+if format_ident<>0 then initialize; {erase preloaded format}
+
+** Version 0.1 incorporates the above changes.
+
+13. This is an extension to the language, put in to satisfy people who
+objected to the fact that \write (and \openout and \closeout) only
+caused action after being deferred to the next \shipout. Some applications
+call for immediate output, hence a new feature: \immediate followed by
+\openout or \write or \closeout causes the output action to take place
+without delay. For example, \immediate\write{x} is equivalent to
+\shipout\vbox{\write{x}} except that the latter also puts an empty
+page into the DVI file.
+
+The extension requires the following new code:
+13a. Insert `\immediate' after `\closeout' in module 1248.
+13b. Define immediate_code=4 and include the following in module 1252:
+        primitive("immediate",extension,immediate_code);
+13c. Include the following in module 1254:
+        immediate_code:print_esc("immediate");
+13d. And, in module 1256:
+        immediate_code:@<Implement \.{\\immediate}@>;
+13e. Finally, there's a new module inserted after old module 1280.
+Here is the WEB coding for this module:
+
+@ The presence of `\.{\\immediate}' causes the |do_extension| procedure
+to descend to one level of recursion. Nothing happens unless \.{\\immediate}
+is followed by `\.{\\openout}', `\.{\\write}', or `\.{\\closeout}'.
+@^recursion@>
+
+@<Implement \.{\\immediate}@>=
+begin get_nc_token;
+if (cur_cmd=extension)and(cur_chr<=close_node) then
+        begin p:=tail; do_extension; {append a whatsit node}
+        out_what(tail); {do the action immediately}
+        flush_node_list(tail); tail:=p; link(p):=null;
+        end
+else back_input;
+end;
+
+** Version 0.2 incorporates the above changes.
+
+14. Like change 11, this one doesn't affect the program, it just improves
+the documentation: Insert the following definitions in module 106:
+define set_glue_ratio_zero(#) == #:=0.0 {assign representation of zero ratio}
+define set_glue_ratio_one(#) == #:=1.0 {assign representation of unit ratio}
+
+These macros are now introduced in a dozen or so future modules, thereby
+eliminating most of the system-dependent changes needed elsewhere for ratios.
+(Note: I also changed 0 to 0.0 in two places of module 182, where a glue_ratio
+comparision was being made.)
+
+15. Change of module 576 (discovered by HWT, 10/14/82)
+"hd:quarterword" should be "hd:eight_bits".
+(The same error occurs in module 522, but in that module the remedy is
+simply to delete the declaration of hd, since this variable is no longer used.)
+
+16. A most embarrassing bug (discovered by DRF, 10/14/82)
+Replace module 531 by:
+
+@ A mild optimization of the output is performed by the |dvi_pop|
+routine, which issues a |pop| unless it is possible to cancel a
+`|push| |pop|' pair. The parameter to |dvi_pop| is the byte address
+following the old |push| that matches the new |pop|.
+
+@p procedure dvi_pop(@!l:integer);
+begin if (l=dvi_offset+dvi_ptr)and(dvi_ptr>0) then decr(dvi_ptr)
+else dvi_out(pop);
+end;
+
+Now we need to make a few changes to subsequent modules:
+16a. In 549, after "incr(cur_s)", insert
+        if cur_s>0 then dvi_out(push);
+and before "decr(cur_s)", insert
+        if cur_s>0 then dvi_pop(save_loc);
+
+16b. Delete "dvi_out(push);" and "dvi_pop;" from modules 553, 558, 562, 567.
+
+16c. Change module 559 just as in 16a.
+
+17. Module 605, line 6 (discovered 10/15/82)
+The test should be "prev_depth>ignore_depth"
+
+** Version 0.3 incorporates the above changes.
+
+18. Module 11 (noticed by WLS, 10/16/82)
+Delete the definition of align_size (it's harmless but never used)
+
+19. (This change and the next cause major changes to the TRIP output;
+file TRIP.LOG and its relatives are being kept up to date on area [tug,dek].)
+The change avoids error messages when vpackage is called during output.
+Such messages can occur when there was no error, because the page is being
+boxed without the \skip glue from its insertions; so they should be omitted.
+The user who really wants such messages can still get them by saying
+"\setbox255=\vbox to 1ht255{\unbox255}".
+In module 903, insert the followng before the declaration of "wait":
+        save_vbadness:integer; {saved value of |vbadness|}
+        save_vfuzz: scaled; {saved value of |vfuzz|}
+Then in module 924, insert
+        save_vbadness:=vbadness; vbadness:=inf_bad;
+        save_vfuzz:=vfuzz; vfuzz:=max_dimen; {inhibit error messages}
+before the call on vpackage, and
+        vbadness:=save_vbadness; vfuzz:=save_vfuzz;
+after.
+
+20. Module 917 computes |page_size| improperly. (Noticed 10/21/82)
+Delete the statement "page_so_far[1]:=page_so_far[1]+width(q);"
+and change the preceding statement to:
+        page_size:=page_size-h-width(q);
+(The comment about page_so_far in the first paragraph of module 895 is
+correct; I mistakenly introduced a bug in module 917 some months after
+writing the first draft of the code, believing that I was making the
+algorithm more elegant or something.)
+
+** Version 0.4 incorporates the above changes.
+
+21. Since TeX82 applied to (the "woven" documentation) TEX.TEX uses
+about 11500 words of variable-size memory, I'm increasing hi_mem_size
+(in module 12) from 12000 to 13000. Actually, I recommend using considerably
+larger values for mem_max and hi_mem_size, whenever possible.
+
+22. Addition of the \boxmaxdepth parameter (10/22/82):
+This involves renumbering hfuzz_code through dimen_pars, in module 234,
+to numbers 9 through 18; inserting the lines
+        @d box_max_depth_code=8 {maximum depth of explicit vboxes}
+        @d box_max_depth==dimen_par(box_max_depth_code)
+        box_max_depth_code:print_esc("boxmaxdepth");
+to module 234 and
+        primitive("boxmaxdepth",assign_dimen,box_max_depth_code);
+to module 235; and changing the call on vpack in module 996 to
+        vpackage(link(head),saved(2),saved(1),box_max_depth);
+
+** Version 0.5 incorporates the above changes.
+
+23. Module 1224, line 4 (bug found by GMK/HWT on 10/26/82)
+change "(k+x>eqtb_size)" to "(k+x>eqtb_size+1)"
+
+24. Module 247, line 13 (bug found 10/26/82)
+(bug was reflected in TRIP.LOG but not noticed)
+change "ch_code(p)" to "ch_code(p-single_base)"
+
+25. Module 670, line 18 (bug found 10/27/82)
+interchange the statements "fetch(...)" and "math_type(...):=..."
+(since the fetch routine sometimes has a side-effect of changing math_type)
+A major change (Version 0.6) made on October 28:
+The following list of changes counts as "number 26" on the list.
+Fonts now have identifiers instead of code numbers; the "\:" primitive
+has disappeared; and there are associated new features for "\the".
+
+a. In module 11, delete bad_font_code.
+b. In modules 170 and 172, delete print_esc(":"), and change
+        `print_int(font_code' to `sprint_cs(font_ident'.
+c. In module 205, the comment for set_font is revised.
+d. In module 217, there are now five locations for control sequences
+        that are perpetually defined; undefined_control_sequence
+        is therefore defined to be frozen_control_sequence+5.
+e. In module 248, sprint_cs is now included among <Basic printing procedures>.
+f. Delete the primitive ":" in modules 250 and 251.
+g. Add to module 376: <Declare procedures that scan font-related stuff>
+h. In module 377, seven levels are now distinguished; we define
+        font_val=4, ident_val=5, tok_val=6.
+i. In module 380, delete the previous cases for def_family and set_font,
+        and the following takes the place of case assign_toks:
+          assign_toks,def_family,set_font,def_font: <Fetch a token list or
+                font number or font identifier, provided that level=tok_val>;
+j. Module 382 (which now has a new name) has this new ending:
+        else if cur_cmd=assign_toks then scanned_result(equiv(m))(tok_val)
+        else <Fetch a font number or a font identifier>
+k. Module 389 becomes
+        <Fetch a font number or a font identifier>=
+        if cur_cmd=set_font then scanned_result(cur_chr)(font_val)
+        else if cur_cmd=def_font then
+                scanned_result(font_ident[cur_font])(ident_val)
+        else    begin scan_four_bit_int;
+                scanned_result(font_ident[equiv(m+cur_val)])(ident_val);
+                end
+l. In module 393, the relation `<>tok_val' becomes `<=mu_val'.
+m. In module 426, the relation `=tok_val' becomes '>=ident_val'.
+        Also add a new case to the case statement:
+          font_val: begin print(font_name[cur_val]);
+                if font_size[cur_val]<>font_dsize[cur_val] then
+                        begin print(" at "); print_scaled(font_size[cur_val]);
+                        print("pt");
+                        end;
+                end;
+n. The body of module 427 becomes:
+        begin p:=temp_head; link(p):=null;
+        if cur_val_level=ident_val then store_new_token(cs_token_flag+cur_val)
+        else if cur_val<>null then
+                begin r:=link(cur_val); {do not copy the reference count}
+                while r<>null do
+                        begin store_new_token(info(r)); r:=link(r);
+                        end;
+                end;
+        the_toks:=p;
+        end
+o. In module 480, delete user_font_code; there's a new comment:
+        When the user defines \font\f, say, TeX assigns an internal number
+        to the user's font \f. For example, if this internal number is 13,
+        we will have font_ident[13]=p and equiv(p)=13, where p is the eqtb
+        location of the control sequence \f.
+p. In module 481, delete the declaration of font_number, and
+        replace the declaration of font_code by
+          font_ident:array[internal_font_number] of pointer;
+q. New stuff in module 483 (also delete references to font_number, font_code):
+        define bad_font_ident=frozen_control_sequence+4 {denotes a null font}
+        font_name[undefined_font]:="nullfont";
+        font_ident[undefined_font]:=bad_font_ident;
+        text(bad_font_ident):="nullfont"; eq_level(bad_font_ident):=level_one;
+        eq_type(bad_font_ident):=set_font;
+        equiv(bad_font_ident):=undefined_font;
+r. In module 490, parameter u is new of type pointer, and the
+        read_font_info subroutine is changed to a function that
+        returns an internal_font_number. There's a new local variable
+          g:internal_font_namber; {the number to return}
+        and we set g:=undefined_font immediately upon entering read_font_info.
+        Also set read_font_info:=g just before exiting.
+s. In module 491, print_int(u) becomes sprint_cs(u).
+t. Delete the statements involving font_code and font_number in module 506,
+        and set g:=f at the end of that module.
+u. The body of module 507 becomes:
+        <Declare procedures that scan font-related stuff>=
+        procedure scan_font_ident;
+        var f:internal_font_number;
+        begin <Get the next non-blank non-call...>;
+        if cur_cmd=set_font then f:=cur_chr
+        else    begin print_nl("! Missing font identifier");
+                help2("I was looking for a control sequence whose")
+                ("current meaning has been defined by \font.");
+                back_error; f:=undefined_font;
+                end;
+        end;
+v. New beginning of module 508:
+        The following routine is used to implement `\texinfo f n'.
+        The boolean parameter writing is set true if the calling program
+        intends to change the parameter value.
+        <Declare procedures that scan font-related stuff>=
+and "scan_font_number" is changed to "scan_font_ident".
+w. In module 509, "print_int(font_code" becomes "sprint_cs(font_ident".
+        Also "font code is defined" becomes "\font is loaded" in the help.
+x. In module 940, the first line of help is changed to
+        "You have to specify a font identifier,"
+y. The set_font case in module 1138 reduces to
+        set_font: define(cur_font_loc,data,cur_chr);
+z. In module 1153, delete all the complicated stuff starting with "scan_int"
+        and substitute simply this:
+                scan_font_ident; define(p,data,cur_val);
+                end;
+aa. Change new_font to new_font(a) in module 1169, and add parameter
+          (a:small_number)
+        in module 1170. Also add the label common_ending, and declare
+        variable u to have type pointer. The code beginning with "scan_int"
+        is changed to the following:
+          get_token;
+          if cs_ptr=0 then
+                 <Complain about the missing control sequence and return>;
+          u:=cs_ptr; scan_optional_equals; scan_file_name;
+          <Scan the ``at'' size specification>;
+          <If this font has already been loaded, set f to the internal
+                font number and goto common_ending>;
+          f:=read_font_info(u,cur_name,cur_area,s);
+          common_ending: define(u,set_font,f); font_ident[f]:=u;
+          exit:end;
+bb. New module 1172:
+        When the user gives a new identifier to a font that was previously
+        loaded, the new value becomes the font_ident of record.
+        Font names `xyz' and `XYZ' are considered to be different.
+        <If this font has already been loaded...>=
+        for f:=font_base+1 to font_ptr do
+                if [the test previously in module 1174] then goto common_ending
+cc. New module 1173:
+        <Complain about the missing control sequence and return>=
+        begin print_nl("! A font identifier must be a control sequence");
+        help2("You should say, e.g., `\font\f=fontfilename'.")
+        ("(I'm going to ignore the \font command you just gave.)");
+        back_error; return;
+        end
+dd. New module 1174:
+        <Cases of print_cmd_chr...>=
+        set_font:begin print("select font "); print(font_name[chr_code]);
+                if font_size[chr_code]<>font_dsize[chr_code] then
+                        begin print(" at "); print_scaled(font_size[chr_code]);
+                        print("pt");
+                        end;
+                end;
+ee. Delete the comment at the beginning of module 1227, and delete the
+        loop for k:=0 to bad_font_code-1, and delete dump_int(undefined_font).
+ff. Delete the repeat loop in module 1228.
+gg. Change font_code to font_ident in module 1229, and change
+        print_int(font_code to sprint_int(font_ident.
+hh. In module 1230,
+        begin undump(single_base)(undefined_control_sequence)(font_ident[k]);
+        undump_qqqq(font_check[k]); [and continue as before]
+
+The changes above have been incorporated into Version 0.6.
+The ill-fated Version 0.7
+
+27. (Here's a change that I retracted shortly after making it, since I
+discovered that the source was flaky after all; and I also found a reliable
+source [NBS Circular 570] confirming my original information. I include
+the note here only for historical purposes...)
+
+"After years of searching, I've finally found a definitive definition of
+the printer's point; and (unfortunately) my previous conjecture was wrong.
+The truth is that 83pc=35cm, exactly; so I am changing TeX to conform.
+This means some changes in the comments of modules 101 and 517, and the
+following changes to the program:
+
+"27a. In modules 547 and 571, the appropriate DVI numbers are now:
+        dvi_four(109375); dvi_four(2039808); {conversion ratio for sp}
+"27b. The guts of module 418 become:
+        if scan_keyword("in") then set_conversion(63246)(875)
+        else if scan_keyword("pc") then set_conversion(12)(1)
+        else if scan_keyword("cm") then set_conversion(996)(35)
+        else if scan_keyword("mm") then set_conversion(498)(175)
+        else if scan_keyword("bp") then set_conversion(10541)(10500)
+        else if scan_keyword("dd") then set_conversion(996)(931)
+        else if scan_keyword("cc") then set_conversion(11952)(931)
+        else..."
+
+*** Version 0.7 of TeX incorporated the changes above (82/10/30);
+this version was withdrawn on 82/11/2.
+Changes subsequent to Version 0.6
+
+28. The experience with #27 did lead me to one improvement, thanks
+to Chuck Bigelow, with respect to Didot points. (11/4/82)
+Add the following comment to module 418:
+        According to the definitions here, $\rm2660\,dd\approx1000.33297\,mm$;
+        this agrees well with the value $\rm1000.333/,mm$ cited by Bosshard
+        in {\sl Technische Grundlagen zur Satzherstellung\/} (Bern, 1980).
+And change two lines of the code there as follows:
+        else if scan_keyword("dd") then set_conversion(1238)(1157)
+        else if scan_keyword("cc") then set_conversion(14856)(1157)
+
+29. The new font material is made more robust by ensuring that \the\font
+always returns a pointer to a control sequence whose command code is
+set_font. (Change 11/4/82)
+
+29a. The code changed in 26aa is changed again, to the following:
+        <If the next token isn't a control sequence, issue a complaint and
+                return; otherwise set u:=cs_ptr, and set hash_used to the
+                location of a ``frozen'' copy of the new font identifier>;
+        define(u,set_font,undefined_font);
+        scan_optional_equals; scan_file_name;
+        <Scan the ``at'' size specification>;
+        <If this font has already been loaded, set f to the internal
+                font number and goto common_ending>;
+        f:=read_font_info(u,cur_name,cur_area,s);
+        common_ending: equiv(u):=f; geq_define(hash_used,set_font,f);
+        font_ident[f]:=hash_used;
+        exit:end;
+29b. Instead of 26cc, here's the new module 1173:
+        We reserve a special control sequence for the font identifier;
+        this one cannot be redefined by the user, so it is safe to
+        return it as a value of \the\font.
+        <If the next token isn't a control sequence...>=
+        get_token;
+        if cs_ptr<hash_base then
+            begin print_nl(
+             "! A font identifier must be a multiletter control sequence");
+            help2("You should say, e.g., `\font\ffn=fontfilename'.")
+            ("(I'm going to ignore the \font command you just gave.)");
+            back_error; return;
+            end;
+        repeat if hash_is_full then overflow("hash size",hash_size);
+        decr(hash_used);
+        until text(hash_used)=0; {search for an empty location in hash}
+        u:=cs_ptr; text(hash_used):=text(u); {copy the name}
+        stat incr(cs_count); tats
+
+30. Module 993, replace lines 5 to 7 (11/5/82):
+else    begin if k=vmode then new_save_level(vbox_group)
+        else    begin new_save_level(vtop_group); k:=vmode;
+                end;
+        if looseness<>0 then eq_word_define(int_base+looseness_code,0);
+        if hanging_indent<>0 then
+                eq_word_define(dimen_base+hanging_indent_code,0);
+        if par_shape_ptr<>null then eq_define(par_shape_loc,shape_ref,null);
+        end;
+
+31. Module 403, replace line 5 (11/6/82):
+if cur_tok<cs_token_flag then
+        begin cur_val:=cur_chr;
+        if cur_cmd<=right_brace then
+                if cur_cmd=right_brace then incr(align_state)
+                else decr(align_state);
+        end
+
+32. Improvements to error recovery for bad alignments (11/6/82):
+In module 1039, replace "begin align_error; goto reswitch; end" by "align_error"
+In module 1040, delete "cur_cmd:=left_brace;" and "cur_cmd:=right_brace;"
+        and change "error" to "back_error"
+In module 1041, delete "cur_cmd:=relax;"
+
+33. More power to \let (11/8/82):
+33a. Module 1141 becomes:
+        <Assignments>+=
+        let:    begin get_token;
+                if cs_ptr<>0 then <Carry out the \let operation>
+                else    begin print_nl
+                         ("! You can use \let only with control sequences");
+                        help2("I'm not \let-ting anything change here,")
+                                ("since I can only do things like `\let\a=b'.");
+                        back_error;
+                        end;
+                end;
+33b. Module 1142 becomes:
+        <Carry out the \let...>=
+        begin p:=cs_ptr;
+        repeat get_token;
+        until cur_cmd<>spacer;
+        if cur_tok=other_token+"=" then
+                begin get_token;
+                if cur_cmd=spacer then get_token;
+                end;
+        if cur_cmd>=call then add_token_ref(cur_chr);
+        define(p,cur_cmd,cur_chr);
+        end
+
+34. This change helps you see an undefined control sequence
+in certain unusual cases (discovered by JDH, 11/8/82):
+Add the clause "(base_ptr=input_ptr) or" to module 294, line 2.
+
+35. Here's an improvement in the formula for demerits; previously
+more weight was given to minimizing bad spacing on lines with penalties,
+so that (slightly loose hyphenated line)(OK line) was considered worse
+than (OK hyphenated line)(quite loose line). (fixed 11/8/82)
+Change lines 2--7 of module 772 to the following:
+        d:=line_penalty+b; d:=d*d;
+        if pi<>0 then
+                if pi>0 then d:=d+pi*pi
+                else if pi>eject_penalty then d:=d-pi*pi;
+
+36. Minor change to save buffer space in non-INITEX (11/10/82):
+Enclose the declaration of pool_file in module 50 by init...tini.
+
+37. Minor improvement in format for the context of error messages (11/13/82):
+37a. Module 289, type "inserted" split into "backed_up=3", "inserted=4"
+and the other type numbers increase: "macro=5", etc.
+37b. In module 296, backed_up: if loc=null then print_nl("<recently read>")
+                        else print_nl("<to be read again> ");
+                inserted: print_nl("<inserted text> ");
+37c. Minor changes to comments in modules 289 and 293.
+37d. Change "inserted" to "backed_up" in module 294.
+37e. Add definition "back_list(#)==begin_token_list(#,backed_up)" in module 305.
+37f. In module 306, first test should be ">=backed_up", second "<=inserted".
+37g. Change ins_list to back_list in modules 307, 318, 375, 1195.
+37h. Add definition to module 308:
+        ins_error==begin back_error; token_type:=inserted; end
+37i. Change back_error to ins_error in modules 362, 1040, 1046.
+37j. Change "<to be read again>" to "<inserted text>" in module 973 help.
+
+38. Module 407, the error message is changed (11/11/82) to:
+"! Missing number, treated as zero".
+
+39. Fix anomaly when hbadness or vbadness is small (11/11/82):
+Module 593, line 2, "if (-x-total_shrink[normal]>hfuzz) or (hbadness<100)"
+Module 603, line 2, "if (-x-total_shrink[normal]>vfuzz) or (vbadness<100)"
+
+40. Added the \tokens primitive (11/13/82):
+In module 223, defined tokens_loc and tokens (analogous to every_par).
+In module 225, defined the primitive.
+In module 1146, changed the comment to include tokens_loc as a possibility.
+
+41. Change get_nc_token to get_token in module 374 (11/13/82).
+(In particular \def\foo{...}\foo won't say "undefined c.s." now!)
+(This change later retracted during debugging; it was found that
+"endv" aborts the job, so this cure was worse than the disease. Then
+it was re-established as part of the major change to conditionals,
+because endv needed to be more robust anyway.)
+
+42. In module 699, we make \span expand in a preamble (11/13/82).
+Change lines -7 through -3 to:
+        begin get_nc_token; goto reswitch;
+        end;
+
+43. Modules 321 and 322 have been altered for better efficiency (11/12/82)
+and better exposition; the three conditions of module 322 are now
+in separate if tests.
+
+44. Frozen control sequences are now unredefinable. (11/16/82)
+A new procedure get_r_token has been introduced to give uniform error
+messages for \def, \let, \read, \font, \mathchardef, and to make them
+incapable of changing the frozen equivalents.
+
+Incidentally, get_nc_token is changed to get_x_token; and ch_code
+becomes cat_code.
+A major change (Version 0.8) made on November 14--16:
+Conditional statements are taken from semantics to syntax.
+
+This change, which counts as number 45 on the list, made it necessary
+to renumber the modules. And it was such a drastic change, the
+differences can only be sketched here, using the old module numbers
+for reference. A variety of other things were cleaned up because this
+change made it more natural for them to be handled differently.
+
+45a. Module 158, inserted a permanently empty token list called null_list.
+45b. Module 204, deleted if_test, case_branch, else_code, convert;
+        inserted end_cs_name.
+45c. Module 206, inserted if_test, fi_or_else, cs_name, convert, and
+        end_template (the latter comes after long_outer_call).
+45d. Module 217, there are now nine frozen control sequences; also null_cs.
+45e. Modules 247 and 248, must be able to print a null control sequence.
+45f. Module 268 (leave_transparent_group) disappears; comments in the
+        previous modules also are appropriately simplified.
+45g. Module 273, delete endv_token.
+45h. Modules 277 and 278, delete references to endv (it no longer appears).
+45i. After module 281, a procedure show_cur_cmd_chr takes the
+        code for tracing commands from module 937.
+45j. Module 317 now forbids \outer control sequences when skipping,
+        and inserts \fi in front of them, for error recovery.
+45k. Module 334 now uses null_cs if carriage-return is an escape.
+45l. Module 343 no longer has endv test.
+45m. Module 344, major extensions to expand_calls make it several modules
+        longer. It saves global variables like cur_val. It changes
+        end_template to endv. It processes cs_name and convert.
+        It processes if_test by calling the "conditional" procedure.
+        It processes fi_or_else by checking their legality, and (if legal)
+        updating the if stack.
+45n. Module 373 (pass_block) disappears.
+45o. After module 400, radix and cur_val and cur_val_level are initialized.
+45p. Module 428 changes so that conv_toks is a procedure rather than a
+        function; this procedure is invoked by expand_calls.
+45q. Modules 436 and 1032, delete reference to conv_toks.
+45r. After module 443, the entire part 48 moves to this part of the program,
+        and the parts are renumbered accordingly. \case is changed to
+        \ifcase, and it resides under the if_test command.
+        New routines are inserted to maintain a linked stack that records
+        the current state of conditionals. There's a procedure
+        pass_text that skips text while looking for \fi or \else or \or
+        on level zero with respect to \if...\fi nesting. The previous
+        routines for skip control via handle_right_brace are eliminated,
+        and the new ones are somewhat simpler. The new \ifcat is mostly
+        combined with the old \if; they no longer ignore spaces.
+        The scanner_status is set to normal while processing \ifx.
+        \ifx will consider \a to equal 0 after \let\a=0.
+45s. Modules 701, 707: endv_token is replaced by a token for a frozen
+        control sequence whose command code end_template makes it behave
+        like an outer_call. After expand_calls, it is converted to another
+        frozen control sequence, whose command code is endv. This two-step
+        facilitates error recovery, instead of giving a fatal error stop.
+45t. Module 874, remove "pass_block(1); goto done".
+45u. After module 1047, routine for end_cs_name prints an error message.
+45v. Module 1049, get_nc_token becomes get_token. (else $\ifmmode fails)
+45w. Module 1202 gets another case (end_template).
+45x. Module 1243, new warning is printed if the if stack isn't empty.
+Changes after version 0.8
+
+46. Declare c : ascii_code in module 825 (noted by DRF, 11/21/82)
+
+47. Module 776 lines 4-6 (suggested by DRF, 11/21/82)
+threshold:=pretolerance;
+if threshold>=0 then
+        begin stat if tracing_stats>2 then
+                begin begin_diagnostic; print_nl("@@firstpass");
+                end; tats
+        second_pass:=false;
+        end
+else    begin threshold:=tolerance; second_pass:=true;
+        end;
+
+48. Protection for DVI files (added 11/16/82)
+Replace lines 2 and 3 of module 570 by:
+        <Update the values of max_h and max_v; but if the page is too large,
+                goto done>;
+Move the statement "dead_cycles:=0" from module 570 to module 568.
+Declare "label done;" in module 568.
+And add the following new module after 570:
+
+@ Sometimes the user will generate a huge page because other error messages
+are being ignored. Such pages are not output to the \.{dvi} file, since they
+may confuse the printing software.
+
+@<Update the values of |max_h| and |max_v|; but if the page is too large...@>=
+if (height(p)>max_dimen)or(depth(p)>max_dimen)or(width(p)>max_dimen) then
+        begin print_nl("! Huge page cannot be shipped out");
+        help2("The page just created is more than 18 feet tall or")@/
+         ("more than 18 feet wide, so I suspect something went wrong.");
+        error;
+        if tracing_output=0 then
+                begin begin_diagnostic;
+                print_nl("The following box has been deleted:");
+                show_box(p);
+                end_diagnostic(true);
+                end;
+        goto done;
+        end;
+if height(p)+depth(p)>max_v then max_v:=height(p)+depth(p);
+if width(p)>max_h then max_h:=width(p)
+
+49. New features \everymath and \everydisplay (12/2/82).
+Make changes analogous to those for "\tokens" (see change 40).
+Put the following just before the end of module 1050:
+  if every_math<>null then begin_token_list(every_math,every_math_text);
+And put the following just before the end of module 1056:
+  if every_display<>null then
+        begin_token_list(every_display,every_display_text);
+
+50. New feature \futurelet (12/2/82):
+Module 1141 changes again. (Also, "let" and "futurelet" share cmd code "let".)
+let:    begin n:=cur_chr;
+        get_r_token; p:=cs_ptr;
+        if n=normal then
+                begin repeat get_token;
+                until cur_cmd<>spacer;
+                if cur_tok=other_token+"=" then
+                        begin get_token;
+                        if cur_cmd=spacer then get_token;
+                        end;
+                end
+        else    begin get_token; q:=cur_tok; get_token; back_input;
+                cur_tok:=q; back_input; {look ahead, then back up}
+                end; {|back_input| doesn't affect |cur_cmd|, |cur_chr|}
+and continue with "if cur_cmd>=call", as before.
+
+*** The changes above have been incorporated into version 0.9 of TeX.
+Changes after version 0.9
+
+51. new \endinput primitive (suggested by FY, 12/7/82):
+\input and \endinput both use the same command code. The cases in module
+955 are deleted and replaced by those in module 965 (which disappears),
+because \input is now allowed in any mode. The code for any_mode(input)
+is "if cur_chr=0 then start_input else force_eof:=true", and it moves from
+module 952 to just before module 1197. The global variable force_eof
+is initially false, and module 340 becomes (after first:=start;)
+        if not force_eof then
+                begin if input_ln.... else force_eof:=true;
+                end;
+        if force_eof then begin print_char(")"); force_eof:=false;...
+
+52. Module 1005, line 4 (12/8/82)
+change "if align_state<0" to "if (mode<0)or(align_state<0)"
+(This avoids embarrassing case where TeX says "type a command or say \end"
+but when you type \end it says "You can't use \end in restricted horiz mode".)
+
+53. Patch to the new code for \csname (12/21/82)
+After eq_type(cs_ptr):=relax, also say equiv(cs_ptr):=256.
+(This corrects a bug that would appear only if \csname occurs right
+after a file name.)
+
+54. Change 47 introduced a bug when tracingonline=0 (12/20/82)
+when omitting firstpass, also do "if tracing_stats>2 then begin_diagnostic;"
+
+55. \hskip -1pt plus 2pt was parsed as \hskip -(1pt plus 2pt)! (12/20/82)
+In module 421, before line -4, insert the following:
+        if negative then
+                begin cur_val:=-cur_val; negative:=false;
+                end;
+But then realize that "negative" is always false on line -2; simplify.
+
+56. Cosmetic change to paragraph statistics (12/23/82)
+tight_fit..very_loose_fit codes have been renumbered very_loose_fit..tight_fit.
+
+57. Module 729 changes to make TeX language more consistent (12/23/82):
+else if type(tail)<>glue_node then tail_append(new_penalty(inf_penalty))
+else    begin type(tail):=penalty_node; delete_glue_ref(glue_ptr(tail));
+        flush_node_list(leader_ptr(tail)); penalty(tail):=inf_penalty;
+
+58. Commas are allowed as alternates to radix points. (12/23/82)
+define continental_point_token=other_token+"," {decimal point, Eurostyle}
+in module 400, and insert the following twice in 409:
+        if cur_tok=continental_point_token then cur_tok:=point_token;
+
+59. \hangindent becomes a normal parameter. (12/23/82)
+This simplifies the code in obvious ways; for example, module 1148 disappears.
+The command code hang_indent goes away too; what was previously called
+hanging_indent is then renamed hang_indent.
+
+60. \prevgraf becomes accessible. (12/23/82)
+This involves renaming the "after" field "pg_field" in the nest array;
+making a new command code set_prev_graf;
+including the following loop into scan_the:
+        nest[nest_ptr]:=cur_list; p:=nest_ptr;
+        while abs(nest[p].mode_field)<>vmode do decr(p);
+        scanned_result(nest[p].pg_field)(int_val);
+and including the following active procedure for any_mode(set_prev_graf):
+        procedure change_prev_graf;
+        var p:0..nest_size; {index into |nest|}
+        begin nest[nest_ptr]:=cur_list; p:=nest_ptr;
+        while abs(nest[p].mode_field)<>vmode do decr(p);
+        scan_optional_equals; scan_int;
+        if cur_val<0 then
+                begin print_nl("! Bad \prevgraf");
+                help1("I allow only nonnegative values here.");
+                int_error(cur_val);
+                end
+        else    begin nest[p].pg_field:=cur_val; cur_list:=nest[nest_ptr];
+                end;
+        end;
+
+61. \clubpenalty is split off from \widowpenalty. (12/23/82)
+
+62. Bad bug in module 1005 (12/24/82)
+(must not go to reswitch if \par is a macro!)
+Instead of setting cur_cmd and cur_chr and goto reswitch, just back_input
+and set token_type:=inserted.
+
+63. \openin not to prompt if file not present (12/25/82)
+Change lines -4 and -3 of module 1183 to:
+        if a_open_in(read_file[n]) then read_open[n]:=just_open
+        else read_open[n]:=closed;
+
+64. New \jobname primitive (12/25/82)
+It is added to the "convert" command in the obvious way.
+In conv_toks, the relevant code is
+        if job_name=0 then open_log_file
+before "selector" is changed and
+        print(job_name)
+after.
+
+65. Better error recovery for math-only things (12/25/82):
+In module 952, don't goto reswitch after insert_dollar_sign.
+In module 954, first back_input, then set cur_tok, and
+don't bother to set cur_chr or cur_cmd; ins_error instead of back_error.
+
+66. Module 1163, line 3, insert "scan_optional_equals" (12/25/82).
+Also make \the\parshape allowed.
+
+67. The location where an \if begins is stacked (12/26/82)
+so that a better error message can be given for \end while \if is incomplete.
+This means two-word nodes instead of one-word nodes in the if stack.
+
+68. Change 30 is extended to \insert, \vadjust, \valign, \output (12/26/82)
+The one-time-only paragraph parameters are now cleared by a
+subroutine called normal_paragraph; hang_after is also set to 1.
+The essential change being made now is to call normal_paragraph in modules
+704, 932, 1009, and 1076.
+
+69. \pagetotal and \pagegoal are added (12/27/82)
+The changes are analogous to, but simpler than, those for \prevgraf.
+
+70. Tracing of page-optimization calculations (12/27/82)
+A bunch of print commands are added to modules 897, 914, and 918,
+activated if tracing_pages>0. Also, \tracingparagraphs is separated
+from \tracingstats.
+
+**** The changes above have been incorporated into version 0.91 of TeX
+
+71. The build_page procedure is broken in two parts (Dec 31, 1982)
+by making module 919 into a procedure called fire_up.
+
+72. \ifeven1\else is made legal by introducing if_code (Dec 31, 1982)
+This improves part of the code in change 45; if_limit has a specific
+value that recovers automatically from a former syntax error.
+
+73. Improvement to alignments when columns don't occur (Dec 31, 1982)
+Delete module 711; and where it was used in module 708, say this:
+        begin fin_col:=true; return;
+        end;
+Also, in module 717, replace the statement "width(q):=0" by
+"<Nullify width(q) and the tabskip glue following the current column>"
+where that new module has the following code:
+        begin width(q):=0; r:=link(q); s:=glue_ptr(r);
+        if s<>zero_glue then
+                begin add_glue_rel(zero_glue); delete_glue_ref(s);
+                glue_ptr(r):=zero_glue;
+                end;
+        end
+
+74. Better error message in overfull alignment (Dec 31, 1982)
+In module 717, don't set both height and width; set the height zero.
+Then in module 719, switch width to height if necessary.  (People didn't
+understand the previous error messages, and I couldn't blame them.)
+
+*** The changes above have been incorporated into version 0.92 of TeX82
+*** (which was the last version of 1982, completed 11:59pm on December 31)
+The first changes after 1982
+
+75. Modules 961 and 962 should be one module. (Jan 3, 1983)
+Also, the absolute constant 100 is replaced, and the test becomes
+        if ((page_head=page_tail)and(head=tail)and(dead_cycles=0))or
+                 (dead_cycles>max_dead_cycles) then
+
+76. Surprise bug: module 1010. (Jan 3, 1983)
+The case "if head<>tail" needs an else clause: else pop_nest.
+Also remove the "<Scan an optional space>" in that module.
+
+77. Improvement to change 22 (Jan 4, 1983)
+In module 996, use box_max_depth from inside the \vbox:
+        @!d:scaled; {maximum depth}
+        begin d:=box_max_depth; unsave;... vpackage(...,d);
+
+78. \groupbegin and \groupend changed to \begingroup and \endgroup (Jan 4, 83)
+
+79. \deadcycles made accessible (Jan 4, 83)
+
+80. New calculations for split insertions (Jan 4, 83)
+In module 918, we now work with natural width, and add in the page depth too:
+The line "else w:=x_over_n..." is changed to
+        else    begin w:=page_goal-page_total-page_depth;
+                if count(n)<>1000 then w:=x_over_n(w,count(n))*1000;
+                end;
+(Note that cur_page_height and cur_page_depth and page_size have been
+renamed page_total, page_depth, and page_goal, in accordance with new syntax.)
+
+*** The changes above have been incorporated into Version 0.93
+
+81. Old bug finally unearthed by PHY (Jan 6, 1983)
+insert "incompleat_node:=null;" after "push_nest;" in module 1097.
+
+82. Extension of change 69: \pageshrink, etc. added (Jan 6, 1983)
+
+83. \floatingpenalty and \insertpenalties added (Jan 6, 1983)
+Also, the insertion nodes now have a new format, so that the values of
+\floatingpenalty, \splittopskip, and \splitmaxdepth can be stored with
+each insertion; this requires the obvious changes in several places:
+a) Module 136, ins_node has fields float,depth,height,ins_ptr,split_top_ptr
+b) Module 184, these fields are displayed
+c) Module 198, ins_node case, also delete_glue_ref(split_top_ptr(p))
+d) Module 202, ins_node case, also add_glue_ref(split_top_ptr(p))
+e) Modules 226-228, new integer parameter \floatingpenalty
+f) Module 883, add parameter d to vert_break subroutine
+g) Module 885, use d instead of split_max_depth
+h) Module 890, argument split_max_depth to call of vert_break
+i) Module 894, change width to height (better name)
+j) Module 900, initialize insert_penalties here, not in 901
+k) Module 914, cost to be awful_bad if insert_penalties>=10000
+l) Module 916, add float(p) to insert_penalties if type(r)<>inserting
+m) Module 916, subtract page_depth from delta
+n) Module 918, subtract page_shrink from delta
+o) Module 918, argument depth(p) to call of vert_break
+p) Module 921, insert_penalties:=0, save split_top_skip before calling 925
+q) Module 921, restore split_top_skip before calling 924
+r) Module 928, set split_top_skip:=split_top_ptr(p) before prune_page_top
+s) Module 929, after q:=p, incr(insert_penalties)
+t) Module 929, before free_node, delete_glue_ref(split_top_ptr(p))
+u) Module 933, clear insert_penalties before calling 934
+v) Module 978, more local variables needed
+w) Module 1010, build the newfangled ins_node
+
+84. Scanner goes to new_line when <return> is category 13 (Jan 7, 1983)
+Insert state:=new_line in module 323 just before the reference to module 339;
+and delete "state:=new_line;" from modules 328 and 330 (and their names).
+
+85. Distinguish between user \kern and font \kern (Jan 9, 1983)
+The nontrivial parts of this are to change "type(s)<>kern_node" to
+"(type(s)<>kern_node)or(subtype(s)<>normal)" in modules 809 and 810;
+and to say "kern_node: if subtype(s)=explicit then goto done4" in module 812.
+The \kern primitive now has "explicit" instead of "normal" in 967.
+
+86. "ignorespace" becomes "ignorespaces" (Jan 9, 1983)
+
+87. Don't omit a blank space after \def, \message, \mark, etc. (Jan 9, 1983)
+<Scan an optional space> is removed from modules 431, 848, 874.
+"info(r):=space_token;" and "link(r):=get_avail; r:=link(r);" removed from 1278.
+
+*** The above changes appear in Version 0.94.
+Version 0.95
+
+88. New active characters in math mode (Jan 12, 1983)
+In module 1062, add a label "restart" and change lines -3 and -2 as follows:
+fam(p):=(c div 256) mod 16;
+if c>=var_code then
+  if fam(p)<8 then fam(p):=cur_fam
+  else begin <Convert c to an active character whose equivalent is
+                        ready to be scanned next>; goto restart;
+        end;
+In module 1064, the body of the procedure becomes
+begin if c>='4000 then <Convert c ...> else <the former body>; end
+And there's a new module:
+<Convert c...>=
+begin cs_ptr:=(c mod 128)+active_base;
+cur_cmd:=eq_type(cs_ptr); cur_chr:=equiv(cs_ptr); x_token; back_input;
+end
+
+89. Surprise bug: $1-$ treated the - as binary (Jan 15, 1983)
+New module <Convert a final bin_noad to an ord_noad>=
+        if r_type=bin_noad then type(r):=ord_noad
+is called in module 649 before the call of 678, and in module 651
+in the place where that code already appears.
+
+90. Another oversight (Jan 15, 1983)
+Add "space_factor:=1000;" after "push_nest" in modules 1027, 1029
+
+91. And a more embarrassing one (Jan 16, 1983)
+I forgot "spotless:=false;" at the beginning of the procedure in module 80.
+But while fixing this, I decided to make it more general since IBMers want
+a return code at the end of the job. So there's a history variable that has
+four values: spotless, warning_issued, error_message_issued, fatal_error_stop.
+a) module 75: declare history, define spotless etc.
+b) module 76: initialize history:=spotless
+c) module 80: if history<error_mess... then history:=error_mess...
+d) 80 and 90: history:=fatal_error_stop before jump_out
+e) 92: if history<error_message_issued then
+f) 232: if history=spotless then history:=warning_issued
+g) 1243: if history=warning_issued then print_nl("(see the log...)")
+
+92. "This can't happen" could happen, so there's new error recovery (Jan 16, 83)
+In module 933, replace the call on confusion by a call of the following module:
+        @ @<Recover from an unbalanced output routine@>=
+        begin print_nl("! Unbalanced \output routine");
+        help2("Your sneaky output routine has fewer real {'s than }'s.")@/
+        ("I can't handle that very well; good luck."); error;
+        repeat get_token;
+        until loc=null;
+        end
+In module 1278, replace the call on confusion by a call of:
+        @ @<Recover from an unbalanced write command@>=
+        begin print_nl("! Unbalanced \write command");
+        help2("On this page there's a \write with fewer real {'s than }'s.")@/
+        ("I can't handle that very well; good luck."); error;
+        repeat get_token;
+        until cur_tok=end_write_token;
+        end
+
+93. String overflow clobbered the log file (Jan 18, 1983)
+Also, "confusion" before log file open would cause problems.  Also start_input
+calling open_log_file calling prompt_file_name calling fatal_error!
+To fix these anomalies, open_log_file no longer calls prompt_file_name,
+if interaction<scrollmode; instead, it terminates after printing what went
+wrong. Also, the fatal_error and overflow and confusion procedures call
+the following new subroutine:
+procedure normalize_selector;
+begin if job_name>0 then selector:=term_and_log else selector:=term_only;
+if interaction=batch_mode then decr(selector);
+if job_name=0 then open_log_file;
+end;
+
+94. \ifeof\fi loops infinitely (Jan 18, discovered by Lamport)
+Change 72 converted such a \fi to <space>\fi. Now it is converted to \relax\fi.
+
+95. \limitswitch changed to \displaylimits et al. (Jan 18, 1983)
+[Incidentally, this fixes a bug in the former positioning of \int\limitswitch]
+a) module 608: subtype of Op can be normal, limits, or no_limits.
+b) 620: display the subtype if not normal
+c) 667: new logic decides limits before looking at the operand (and the operand
+ is now called the nucleus); the italic correction is removed only if
+ it should not be put back
+d) 1069: subtype(tail):=cur_chr
+
+96. Minor changes to math in unusual cases (Jan 19, 1983)
+a:delete "if height(y)<=0 then height(y):=default_rule_thickness" in module 658
+b:move "if thickness(q)=default..." from module 664 to module 661
+c:delete module 1081, that error message isn't worth the bother
+d:in module 1062, char_num case, c:=math_code(cur_val) (if cur_val<128)
+e:in module 1064, a similar change
+
+97. Bad spacing from change 6 is corrected (Jan 19, 1983)
+underline, overline, radical, vcenter, and accent noads now revert to type
+Ord instead of type Inner.
+{...} produces type Ord also.
+There's a new primitive \mathinner.
+The new_noad function now produces an ord_noad (change its calls accordingly).
+And the default is changed in module 679 to t:=ord_noad; the fraction_noad
+case sets t:=inner_noad, and the (inner_noad,ord_noad) cases swap places.
+
+98. New \mathchoice primitive (Jan 19, 1983)
+a) module 204: new command
+b) 254: math_choice_group
+c) 614: style node three words long, so a choice node can be converted to it
+d) 614a: choice node has four subfields: display_mlist, text_mlits, etc.
+e) 1081a: routines to build a choice_node like 1027-1029 build discretionaries
+
+99. \input moves to syntax from semantics (Jan 19, 1983)
+a) 204, 206: renumber commands
+b) When input is to be expanded, if name_in_progress then insert_relax
+c) 459,464: name_in_pr:=true; begin_name;...end_name; name_in_pr:=false;
+d) 406,461: declare name_in_progress, a global boolean initially false
+
+100. \chardef joins \mathchardef (Jan 19, 1983)
+a) 204: math_only becomes math_given; add new command char_given
+b) 205: new command char_def
+c) 250,251: new primitive char_def
+d) 380: char_given,math_given yield integer after \the
+e) 401: char_given,math_given yield integer in context of integer
+f) 936,943: char_given treated like other_char
+g) 1062,1064: same, if cur_chr<128, else assume math_code(x)=x
+h) 1143,1144: char_def is analogous to math_char_def
+
+101. \unbox becomes \unhbox,\unvbox; also add \unhcopy (Jan 19, 1983)
+Module 1020 changes in the obvious way.
+
+102. \spacefactor, \pagetotal, etc. move to prefixed_command (Jan 20, 1983)
+
+103. \hrule in horizontal mode, \vrule in vertical mode: switch modes (Jan 20)
+
+104. \globaldefs parameter, affects prefixed_command (Jan 20, 1983)
+
+105. After looking at frequency counts, some optimizations made (Jan 21, 1983)
+a) "fast_get_avail" and "fast_store_new_token" introduced to speed up the loops
+in modules 360 and 431.
+b) some procedure call overhead eliminated in begin_token_list, end_token_list,
+back_input, and flush_node_list.
+c) a few if tests changed from "if a and b then" to "if a then if b then".
+
+106. Changes for space efficiency in math constructions (Jan 22, 1983)
+a) In module 1102, mlist_penalties:=(mode>0)
+b) The following code is inserted before "free_node" in module 639 (rebox):
+        if (is_char_node(p))and(link(p)=null) then
+                begin f:=font(p); v:=char_width(f)(char_info(f)(character(p)));
+                if v<>width(b) then link(p):=new_kern(width(b)-v);
+                end;
+c) A new module is called just before clean_box exits:
+<Simplify a trivial box>=
+q:=list_ptr(x);
+if is_char_node(q) then
+        begin r:=link(q);
+        if r<>null then if link(r)=null then if type(r)=kern_node then
+                begin free_node(r,small_node_size); link(q):=null;
+                end;
+        end
+
+107. Oversight in rebox routine (module 639) corrected (Jan 22, 1983)
+if type(b)=vlist_node then b:=hpack(b,natural);
+
+108. Module 217 clobbers eqtb[bad_font_ident] set in change 26q (Jan 22, 1983)
+Decided to fix this by making \nullfont a primitive.
+This means the procedure missing_font can be deleted, and the test for
+undefined font can be removed from the inner loop.
+(This reflects a rather dramatic change from TeX80, where
+a missing font was a fatal "Whoa" error!)
+Note: I thought I could delete module 646, but realized that it still provides
+a useful error message. The dump/undump routines (cf. change 26ee) now
+dump the null_font information too, as its parameters can be changed.
+
+109. End of program now lists all incomplete \ifs (Jan 24, 1983)
+
+110. Alignment preamble setup to allow \halign\lb (Jan 29, 1983)
+The statement "align_state:=-1000000;" is inserted near the beginning
+of module 695 (and the comment about align_state=-999999 is deleted).
+The constant -999999 is changed to -1000000 in modules 700 and 701.
+
+111. Forgot to test is_char_node(r) (Jan 30, 1983)
+in the <Simplify a trivial box> code of change 106c.
+By coincidence, this was caught since somebody used font number 11
+in the second character of a list of length 2!
+
+112. Improved format for stats at end of run (suggested by DRF, Jan 30, 1983)
+Module 1242 changes; nothing subtle.
+
+**** The changes above have been incorporated into version 0.95
+Version 0.96
+
+113. space after one-symbol control sequences NOT to be ignored unless
+the catcode of that symbol is letter or spacer. (Jan 30, 1983)
+The name of module 334 changes slightly; the state is set based
+on cat_code(cur_chr), shortly after label start_cs.
+A new variable cat is introduced and set to cat_code(cur_chr) in modules
+334 and 336.
+
+114. trailing spaces removed on all lines of input (Jan 30, 1983)
+last_nonblank is added to input_ln routine (module 31)
+
+115. mmode+accent gives error but assumes math_accent (Feb 3, 1983)
+This goes into math_ac procedure (module 1075); module 1035 is eliminated.
+
+116. \iftrue and \iffalse (Feb 5, 1983)
+Simple addition of two new conditions.
+
+117. Bad calculation of size for \left and \right (Feb 6, 1983)
+In module 680, the first assignment to delta should be
+        delta:=(delta1 div 500)*delimiter_factor.
+
+118. \delimitershortfall (new name) replaces \delimiterlimit. (Feb 12)
+
+119. \abovewithdelims.. to be equivalent to \above (Feb 12)
+Module 1089 revised so that the delimiters are scanned before the dimension.
+
+120. Remove the kludgy math codes introduced in change 88 (Feb 12)
+\fam becomes a normal integer parameter
+and \mathcode stored with min_halfword added
+and \mathcode allowed to be 32768
+and current family is substituted only when it's in range.
+Also the initialization of mathcode for letters now specifies family 1.
+(This implies a dozen or so obvious revisions.)
+
+121. Bug in module 1152: max spacefactor is 32767 (Feb 12)
+also module 1013 gets a restricted range
+
+122. Octal output to be replaced by hexadecimal. (Feb 14)
+
+123. Forgot to include char_given in module 1037, re change 100 (Feb 14)
+
+124. vmode+valign,hmode+halign made legal transitions (Feb 17)
+
+125. \tracingrestores (Feb 18)
+This involves a lot of new, rather tedious code that's interspersed with the
+eqtb definitions (the body of a procedure called show_eqtb).
+
+126. New error message for hmode+hrule in -hmode. (Feb 25)
+head_for_vmode now suggests \leaders in this case. [improves change 103]
+
+127. under/overfull boxes in alignment: Better message. (Feb 27)
+par_begin_line becomes pack_begin_line, and it is set (negative) in
+module 719, read in modules 590 and 601.
+
+128. New \xcr feature. (suggested by Lamport comments, Mar 4)
+align_peek (module 702) ignores it, otherwise it acts like ordinary \cr.
+
+129. In stats, subtract out TeX's own string requirements (Mar 4)
+(cf. change 112)
+init_pool_ptr and init_str_ptr variables added in obvious way
+(declared in module 39, set in module 1240, used in module 1242)
+
+130. \everyhbox and \everyvbox. (Mar 6)
+The modifications are obvious; for example, module 1076 gets the statement
+        if every_vbox<>null then begin_token_list(every_vbox,every_vbox_text);
+and a similar pair of statements goes into module 993.
+
+131. Precaution in module 1105 error recovery (March 9, 1983)
+Change the first test to "if (a=null)or danger", in order to
+avoid accessing math_quad when the symbol fonts aren't known to be present.
+
+132. Installed float and unfloat to aid portability (suggested by HWT, 3/7/83)
+
+133. \dispskip becomes \abovedisplayskip and \belowdisplayskip (3/9/83)
+Also \dispaskip becomes \abovedisplayshortskip; \dispbskip similar.
+
+134. \romannumeral separated from \number (suggested by FY, March 10)
+Obvious changes; print_roman_int now accepts negative input but gives
+no output in such cases (the test in module 68 becomes "if n<=0 then return").
+
+135. scan_keyword to ignore leading spaces (Mar 12)
+In module 375, change "else begin" to
+"else if (cur_cmd<>spacer)or(p<>backup_head) then begin".
+
+136. Update to change 112 (Mar 14)
+Module 1242 now uses write and write_ln directly (saves space and time).
+
+137. Another change to page-break cost (suggested by Lamport, March 16)
+Cf. change 83k above; the relevant lines of module 914 now read
+        if b<awful_bad then
+                if pi<=eject_penalty then c:=pi
+                else    if b<inf_bad then c:=b+pi+insert_penalties
+                        else c:=deplorable
+        else c:=b;
+        if insert_penalties>=10000 then c:=awful_bad;
+and a similar change (but without insert_penalties) occurs in module 887.
+
+**** The changes above have been incorporated into version 0.96 (March 16, 1983)
+Version 0.97
+
+138. \everyjob (suggested by FY, March 18)
+Module 936: main_control inserts every_job as its first action.
+
+139. Improved printout of macro definitions (March 19)
+In module 278, simply treat left_brace like right_brace.
+(This corresponds to the way the manual describes parameter matching.)
+
+140. Omit blanks as non-delimited parameters (March 19)
+In module 360, replace
+        else store_new_token(cur_tok);
+by
+        else @<Store the current token, but |goto continue| if it is
+                 a blank space that would become an undelimited parameter@>;
+Then define @<Store the current token...@> to be:
+begin if cur_tok=space_token then
+        if info(r)<=end_match_token then
+                if info(r)>=match_token then goto continue;
+store_new_token(cur_tok);
+end
+
+141. Minor patch in module 386, catches mu_glue (March 21)
+begin cur_val:=zero_glue; cur_val_level:=glue_val;
+if not is_char_node(tail)and(mode<>0) then
+        begin if type(tail)=glue_node then
+                begin cur_val:=glue_ptr(tail);
+                if subtype(tail)=mu_glue then cur_val_level:=mu_val;
+                end;
+        end
+else if (mode=vmode)and(tail=head)and(last_page_glue<>max_halfword) then
+        cur_val:=last_page_glue;
+end
+
+142. Patch in module 699, \span expands only one level (March 21)
+(See previous change #42.) The "get_x_token" in the code
+while (cur_chr=span_code)and(cur_cmd=tab_mark) do get_x_token;
+should be replaced by:
+        begin get_token;
+        if cur_cmd>max_command then
+                begin expand_calls; get_token;
+                end;
+        end
+
+143. Single # in \tokens, \message, etc. (March 22)
+(The previous rule was really bad in connection with \uppercase,
+or with \write when #'s had to be given four times!)
+Module 437 should be prefaced with "if macro_def then".
+And get_token should become get_x_token there, if xpand is true.
+
+144. Keyword "to" required in \read. (March 22)
+This will avoid the common error of a missing space before the \cs.
+Also the stream number can be out of range, for terminal input.
+The stream number in a \write can be out of range too, for terminal output.
+Modules 1145 and 1258 and 1280, etc., change in the obvious ways.
+
+145. \ifeven<countnumber> replaced by \ifodd<number> (March 26)
+This makes the language more consistent.
+
+146. Big surprise bug relating to \if\if aabc\fi (March 26)
+(related to change 45; the possibility that cur_if might not be the
+correct one when the conditional is evaluated was discovered today)
+The main change is to add the change_if_limit procedure, and to add
+the variable save_cond_ptr and the code that now depends on it.
+
+147. \if and \ifcat should tolerate primitives (March 28)
+
+148. "absent" becomes "void", a better word (March 28)
+
+149. Module 990: \lastbox to clear the shift_amount (March 28)
+since I don't want to figure out what it means in all cases (\vsplit, etc)
+
+150. print_err("...") takes the place of print_nl("! ...") (DRF, March 29)
+And wake_up_terminal is introduced in module 34, and used in modules
+37, 70, 341, 441, 457, 463, 1210, 1240, 1246.
+
+151. \halign extended to periodic preambles (April 1)
+Modules 688--690: cur_loop introduced, stacked/unstacked
+Module 695: cur_loop initialized
+Module 700: cur_loop set up
+Module 708--709: cur_loop used and advanced
+
+152. \leaders to align by the smallest enclosing box. (April 1)
+Module 549: new local variable left_edge, initialized to cur_h
+Module 557: cur_h:=left_edge+leader_wd*((cur_h-left_edge) div leader_wd)
+Module 559: new local variable top_edge, initialized to cur_v-height(this_box)
+Module 566: analogous to 557
+
+153. hyphenation after whatsits is OK (April 1)
+In module 809, skip past whatsits
+
+154. \par in vertical mode should build_page (April 2)
+vmode+par_end moves from 952 to 1005
+
+155. Clear aux to zero in module 703 (April 2)
+
+156. Digits will switch families (April 4)
+(initialize their math codes differently in module 225)
+
+157. Refinement to correction 83m (April 7)
+the test for not splitting should be
+        if ((h<=0)or(h<=delta))and(height(p)+height(r)<=dimen(n)) then
+
+158. (re 128) \xcr renamed to \crcr, at Lamport's request. (April 8)
+
+159. Better error recovery in runaway preamble (April 11)
+Module 319, aligning: set align_state:=-1000000
+
+160. \read to get balanced braces (April 12)
+Module 440 changed to look more like 431.
+Module 443 gives error message if the \read goes off end of file.
+Module 319 removes \outer from forbidden control sequence that is \read.
+
+161. Bug found by Jim Sterken (April 14)
+Module 798 can make q a char_node, so module 794 needs this patch:
+        if not is_char_node(q) then
+to be inserted just before "if (type(q)=math_node)..."
+
+162. \uppercase and \lowercase to apply to all characters (April 15)
+module 1196 changes; also I put active_base before single_base in eqtb
+
+**** The changes above have been incorporated into version 0.97 (April 16, 1983)
+**** except the part of 144 about \read-1 was forgotten and put in 0.98 later
+Version 0.98
+
+163. change small_number to 0..65 in module 814 (found by DRF, April 17)
+
+164. improved error recovery in module 1166 (suggested by DRF, April 17)
+after error: repeat get_token; until cur_cmd=right_brace; {flush the patterns}
+
+165. improved \read from terminal (suggested by Todd Allen at Yale, May 1)
+I had forgotten to implement the extended stream numbers in change 144.
+Also, the prompt is now omitted if n<0.
+
+166. \write n writes only to the log file, if n<0. (May 18)
+
+167. Unified syntax for parameters and registers. (May 18)
+a) Command code changes: def_font moved to before prefix;
+   register eliminated; set_register renamed register and
+   moved (with adv_register...div_register) to before prefix;
+   min_internal and max_internal defined.
+b) scan_the renamed scan_something_internal, and it acts on cur_tok.
+c) scan_int, scan_dimen, scan_glue simplified accordingly; instead of
+   testing for cur_cmd=the or cur_cmd=register, they now test
+   cur_cmd versus min_internal and max_internal.
+d) ins_the is removed.
+e) \minusthe is removed. Consequently "the_toks" needs no parameter.
+
+168. new parameters \hoffset, \voffset (May 18)
+
+169. \everycr (suggested by Spivak, installed May 24)
+
+170. \countdef, \dimendef, etc. (suggested by DRF long ago, installed May 25)
+Straightforward change to internal representation of assign_int and similar
+commands, so that the chr part is now a pointer to the eqtb location.
+
+171. \advance, \multiply, \divide (suggested by FY, installed May 25)
+
+172. \hyphenchar (May 25)
+A new command assign_font_int is introduced, and incorporated into
+scan_something_internal and prefixed_command in the usual way.
+The hyphen_char array entries are initialized in modules 483 and 506,
+allocated in 482, used in modules 809 [is hyphenation to be suppressed?],
+828 [insert the hyphen character], 946 [insert discretionary node
+following hyphen], 1027 [implementation of \-].
+hyphen_char[k] is dumped and undumped in modules 1229 and 1230.
+
+173. \skewchar (May 25)
+Loaded and fetched with the same command code as \hyphenchar.
+Module 659 gets a dozen more lines of program, to compute the skew.
+
+174. \noexpand (May 25)
+This involves: introduction of no_expand and dont_expand command codes;
+frozen_dont_expand as an internal marker; small change to get_next
+when that marker is sensed; change to processing of \if and \ifcat;
+implementation of no_expand in the expand_calls subroutine.
+I also changed the name of expand_calls to "expand".
+
+175. \meaning (May 25)
+This adds one case to the "convert" command.
+print_meaning is a new subroutine, using code that was in show_whatever.
+
+176. "dm" and "vu" are out, ".5\hsize" is in (May 25)
+Straightforward changes to module 416.
+
+177. \texinfo f n becomes \fontdimen n f (May 25)
+
+178. \afterassignment (suggested by ARK, May 27)
+
+179. \chardef\xx=5\xx shouldn't say that \xx is undefined (May 27)
+
+180. \relax to be ignored like spaces in math mode (May 28)
+and in a few other places: <Get next non-blank non-relax non-call token>
+is now used in modules 379, 988, 994, 1062, 1070, 1134, 1179
+(i.e., scan_left_brace, scan_box, scan_math, scan_delimiter, prefixed_command,
+do_assignments, and just after \leaders).
+
+181. improve \mathaccent wrt sub/superscripts (sugg by HWT, May 30)
+
+182. its_all_over: remove dead_cycles>max_dead_cycles (May 30)
+Modules 961 and 962 are combined and simplified.
+
+*** The changes above were installed into version 0.98 on May 31, 1983 ***
+Version 0.99
+
+183. \mark and \insert and \vadjust allowed in restricted hmode (Jun 3)
+also in math; this is a comparatively big change
+[at present, \mark in a display causes TeX to crash with "can't happen"!]
+modules 652 and 679: mark_node,ins_node,adjust_node now permitted
+modules 576 and 578: t becomes a global variable adjust_tail
+modules 802 and 1110: new calling sequence to get the adjustments
+modules 254, 986, 993, 995, 996: adjusted_hbox_group for the new kind of hbox
+modules 698--690: cur_head and cur_tail added to alignment stack
+modules 703, 712, 715: adjustments gathered and appended during \halign
+
+184. \ht, \wd, and \dp (Jun 6)
+
+185. When displaying noads, use ^ and _ instead of ( and [ (Jun 6)
+
+186. A..F in hex constants could be otherchar as well as letter (Jun 6)
+
+187. Remove <scan optional space> from module 417 (Jun 7)
+(it was redundant code)
+
+188. \mkern .5\thinmuskip and \mkern\thinmuskip should be legal (Jun 7)
+
+189. 2.5\space\space\dimen0 should work (Jun 7)
+previously it worked after "plus" or "minus" only!
+
+190. <font identifier> to allow also \font for current font (Jun 7)
+"if cur_cmd=def_font then f:=cur_font else" added to module 507
+
+191. \gdef not to be global when \globaldefs<0 (Jun 7)
+"and (global_defs>=0)" added to module 1139
+
+192. \advance\spaceskip by-\spaceskip should yield zero_glue (Jun 7)
+the procedure trap_zero_glue is culled from module 1147
+
+193. \show should work with any token (Jun 7)
+
+194. \tokens to become 256 registers (Jun 8)
+\toks and \toksdef added in the straightforward way
+(this affects mainly eqtb, scan_something_internal, prefixed_command)
+
+195. allow \indent in math mode (Jun 8)
+also, \valign in math mode to give missing $ error
+modules 1001 and 1043 disappear; 1004 is generalized slightly.
+
+196. remove redundant code (Jun 8)
+In module 1044, there's no need to check cur_group and call off_save.
+Similarly in module 1053.
+
+197. new_write_whatsit shouldn't allow \openout-1, \closeout-1 (Jun 8)
+(simple change to module 1258)
+
+198. \lastbox should give error in math mode (Jun 8)
+(simple change to module 990)
+
+199. \leaders not followed by proper glue should be back_error (Jun 9)
+[I made the change; TRIP should test this error message!]
+
+200. Module 702, correction to beginning of \noalign (Jun 9)
+if mode=-vmode then normal_paragraph;
+
+201. After alphabetic constant, expand the optional space (Jun 10)
+
+202. Set space_factor:=1000 after rule or constructing an accent (Jun 12)
+That's in modules 964 and 1036.
+
+203. blunder in module 783 (caught by Jim Sterken, fixed Jun 14)
+disc_width:=0 needs to be set before testing if s=null
+(A real bug that existed since the beginning! It showed up on page 37
+  of the September 1982 TRIP manual; my hand-checking was incomplete...)
+
+204. Change to optional spaces after <dimen> (Jun 14)
+The optional space will now be analogous to that after <number>.
+
+205. Fix conflict between \output and \everydisplay (Jun 14)
+In change 49, I should have inserted every_display before calling build_page.
+
+206. Overflow errors to be consistent with statistics reporting (Jun 17)
+(See change 129.)
+
+207. \tracing switches to be all positive vs nonpositive (Jun 17)
+
+*** The changes above were installed into version 0.99 on June 19, 1983 ***
+Version 0.999
+
+208. \catcode`\%=14 to be done by INITEX (Jun 20)
+
+209. \par in vmode to clear parshape etc. (Jun 21)
+Module 1005, which contains vmode+par_end, now calls normal_paragraph.
+
+210. Improvement to change 39 (Jun 21)
+Module 593, overfull_rule not appended if solely due to hbadness
+
+211. Alignment bug allows glue_set to be less than -1! (Jun 21)
+Modules 723 and 724 need to be patched.
+
+212. Correction to change 134 (found by Debby Clark, Jun 22)
+Module 68: n to be declared integer, not nonnegative_integer.
+
+213. "by" to be optional (suggested by Lamport, Jun 22)
+Module 1158 disappears
+
+214. Module 1235, slight change in format_ident message (Jun 24)
+
+215. New measures needed to thwart trickery (Jun 25)
+Glue set values computed by \span could have been brought into
+TeX's registers via, e.g., \valign and \vsplit; so the
+"kern" idea of module 722 is insufficient and should be abandoned.
+Extra boxes and glue are added; this has additional virtue
+of perfect accuracy in alignment of vertical rules.
+The main change is to introduce a new module after 722, in which s and t
+are updated for spans, and to eliminate the "equivalent kern" code from 719
+(the corresponding glue calculations are now done in the new module).
+
+216. leaders to affect height/width of their boxes (Jun 25)
+Module 583 splits into two parts (one for hpack, one for vpack).
+
+217. \unskip permitted a little more often (Jun 28)
+Module 1018 reports error only if last_page_glue<max_halfword.
+
+218. {\bf A} in math: not to make a box (Jul 1)
+Module 1093 changes as follows: info(saved(0)):=fin_mlist(null) becomes
+p:=fin_mlist(null); info(saved(0)):=p; if <simple case> then <simplify>.
+
+219. "scaled" feature added to \font input.
+
+220. \mathaccent still not working right? (Jul 2)
+Change 181, I forgot to correct delta when box x changed.
+
+221. Remove confusion possible on file of length 1 (found by Lamport)
+Correction suggested by DRF, July 2: introduce bypass_eoln
+
+222. Allow things like ^^b. (July 4)
+This simplifies modules 332 and 335; also affects 48 and 49.
+And (surprise) 58.
+
+223. \escapechar \defaulthyphenchar \defaultskewchar \endlinechar (July 4)
+to make TeX less dependent on the character set
+A lot of error messages are now broken up so that they use print_esc
+
+224. erstat added for file opening/closing (by DRF, July 7)
+That's module 27.
+
+225. \tracingpages output to show total glue too (July 11)
+Added a procedure called print_page_totals, used also by show_activities.
+Broke modules 214 and 896 into two modules each.
+
+226. Guard against insertion into an hbox (July 11)
+A new procedure ensure_vbox is called in modules 917 and 925.
+
+227. <tokenvar>=<tokenvar> allowed (July 11)
+
+228. \errhelp parameter added (July 11)
+
+229. get_preamble_token should look at global_defs (July 11)
+Module 699 is patched.
+
+*** The above changes installed in preliminary version 0.999 on July 12, 1983,
+but I decided later in the day to do a few more things:
+
+230. \string, \noexpand, \meaning to allow \outer (Todd Allen, July 12)
+
+231. \the to be an expandable control sequence (July 12)
+Several things in the language are cleaned up:
+a) \the\tenrm replaced by \fontname\tenrm [\fontname<font>]
+b) when expanding edef, etc., result of \the still expanded only one level
+c) expansion after \def not inhibited, since \noexpand is now present
+d) \the\the disallowed.
+
+232. \unhbox and \unhcopy allowed in math mode if the box is void (July 12)
+Module 1020 is extended to handle this case.
+
+233. Value of default_rule was incorrectly rounded (July 16)
+Module 424: default_rule=26214 {.39999 pt}
+
+234. \mathaccent still not right! (July 16)
+I need to make the final height the max of (height of accented letter w/o
+superscript, height of unaccented letter w superscript).
+
+235. \newlinechar parameter (July 16)
+simple change to print subroutine
+
+236. boxes and rules to be allowed in discretionaries (sugg by HP man, July 16)
+in fact this simply requires omitting of the prohibition (in module 1031)
+and a few more cases equivalent to kern_node in modules 754, 755, 784.
+
+237. \tracingcommands to show all expandable tokens (July 16)
+
+238. \char to be allowed in \hyphenation list (July 16)
+Module 848 changes in the obvious way.
+
+239. \aftergroup (July 16)
+A new save_type.
+
+240. Curtail running dimensions inside alignments (sugg by ARK, July 16)
+Module 720.
+
+241. Strange pattern data could cause PASCAL error (found July 17)
+Put "if hc[1]=127 then hyf[0]:=0;" at beginning of module 878.
+
+242. hc codes for hyphenation are one lower (July 17)
+e.g., hc[...]:=lc_code(...)-1. This makes code 127 impossible to match.
+
+243. whatsits also allowed after hyphenatable words (July 17)
+Module 812.
+
+244. \/ makes an explicit kern (July 17)
+"subtype(tail):=explicit" in module 1023.
+
+*** Version 0.999 installed July 17, 1983.
+But later in the day I decided to do a few more things:
+
+245. Lowercase letters allowed in file names (July 18)
+In module 452, omit the conversion to uppercase.
+
+246. "No output file" becomes "No pages of output." (July 18)
+Module 571.
+
+247. QRS on error leads to confirmation message (sugg by ARK, July 18)
+Module 84.
+
+*** The real version 0.999 finally installed July 18.
+* Version 1.0
+
+(Changes made after the Version 0.999 listing of TeX82)
+(Henceforth the "final" module numbers are used)
+
+248. Module 1215, allow space in \read n to \cs (by FY, July 25, 1983)
+@x patch in get_r_token routine
+begin restart: get_token;
+@y
+begin restart: repeat get_token;
+until cur_tok<>space_token;
+@z
+
+249. Module 498, we must stack the current if type (FY, July 27)
+@x patch in conditional routine
+begin @<Push the condition stack@>;@+save_cond_ptr:=cond_ptr;@/
+@y
+@!this_if:small_number; {type of this conditional}
+begin @<Push the condition stack@>;@+save_cond_ptr:=cond_ptr;this_if:=cur_chr;@/
+@z
+Also replace cur_if by this_if in modules 501, 503, 506. The following
+patches do only what is necessary to make things work:
+@x
+  print_cmd_chr(if_test,cur_if);
+@y
+  print_cmd_chr(if_test,this_if);
+@z
+@x
+if cur_if=if_int_code then scan_int@+else scan_normal_dimen;
+@y
+if this_if=if_int_code then scan_int@+else scan_normal_dimen;
+@z
+@x
+if cur_if=if_char_code then b:=(n=cur_chr)@+else b:=(m=cur_cmd);
+@y
+if this_if=if_char_code then b:=(n=cur_chr)@+else b:=(m=cur_cmd);
+@z
+
+250. Module 507, \ifx need not put a control sequence in hash table (July 29)
+@x
+get_token; n:=cs_ptr; p:=cur_cmd; q:=cur_chr;
+get_token; if cur_cmd<>p then b:=false
+@y
+get_next; n:=cs_ptr; p:=cur_cmd; q:=cur_chr;
+get_next; if cur_cmd<>p then b:=false
+@z
+
+251. Module 86, message is lost (noticed by HWT, July 31)
+@x
+print("..."); print_ln; return;
+@y
+print("..."); print_ln; update_terminal; return;
+@z
+
+252. Don't put empty at end of \input file! (Aug 1)
+[This simplifies the rules and the program, and also gets around a bug
+that occurred at the end of files with \endlinechar<0.]
+@x Module 362:
+@ An empty line is inserted at the end of the file, if the last line
+wasn't already empty, because |input_ln| sets |last:=first| when
+it discovers an |eof|.
+@^empty line at end of file@>
+
+@<Read next line of file into |buffer|, or
+  |goto restart| if the file has ended@>=
+begin incr(line); first:=start;
+if not force_eof then
+  begin if input_ln(cur_file,true) then {not end of file}
+    firm_up_the_line {this sets |limit|}
+  else if limit<>start then firm_up_the_line
+    {if |pausing|, the user can add more lines}
+  else force_eof:=true;
+@y
+@ @<Read next line of file into |buffer|, or
+  |goto restart| if the file has ended@>=
+begin incr(line); first:=start;
+if not force_eof then
+  begin if input_ln(cur_file,true) then {not end of file}
+    firm_up_the_line {this sets |limit|}
+  else force_eof:=true;
+@z
+
+*** The changes above went into Version 0.9999, which was widely distributed
+
+253. Ridiculous blunder made in change 146 (found by FY, August 16)
+@x Correction to module 497
+else loop@+begin q:=cond_ptr;
+  if link(q)=p then
+    begin type(p):=l; return;
+    end;
+  if q=null then confusion("if");
+@:this can't happen if}{\quad if@>
+  q:=link(q);
+@y
+else  begin q:=cond_ptr;
+  loop@+  begin if q=null then confusion("if");
+@:this can't happen if}{\quad if@>
+    if link(q)=p then
+      begin type(q):=l; return;
+      end;
+    q:=link(q);
+    end;
+@z
+
+254. Minor amendment to stat(s) printing (cf. change 129) (August 16)
+@x in module 1334
+  wlog_ln(' ',str_ptr-init_str_ptr:1,' strings out of ',
+    max_strings-init_str_ptr:1);@/
+@y
+  wlog(' ',str_ptr-init_str_ptr:1,' string');
+  if str_ptr<>init_str_ptr+1 then wlog('s');
+  wlog_ln(' out of ',
+@z
+
+255. Bug in \xleader computations (found by FY, August 18)
+@x in module 592
+@!lq,@!lr:integer; {quantities used in calculations for leaders}
+@y
+@!lq,@!lr,@!lx:integer; {quantities used in calculations for leaders}
+@z
+@x in module 626
+  begin edge:=cur_h+rule_wd;
+  @<Let |cur_h| be the position of the first box, and set |leader_wd|
+    to the spacing between corresponding parts of boxes@>;
+  while cur_h+leader_wd<=edge do
+    @<Output a leader box at |cur_h|,
+      then advance |cur_h| by |leader_wd|@>;
+@y
+  begin edge:=cur_h+rule_wd; lx:=0;
+  @<Let |cur_h| be the position of the first box, and set |leader_wd+lx|
+    to the spacing between corresponding parts of boxes@>;
+  while cur_h+leader_wd<=edge do
+    @<Output a leader box at |cur_h|,
+      then advance |cur_h| by |leader_wd+lx|@>;
+@z
+@x in module 627
+    leader_wd:=leader_wd+lx;
+@y
+@z
+@x in module 628
+cur_h:=save_h+leader_wd;
+@y
+cur_h:=save_h+leader_wd+lx;
+@z
+@x in module 635
+  begin edge:=cur_v+rule_ht;
+  @<Let |cur_v| be the position of the first box, and set |leader_ht|
+    to the spacing between corresponding parts of boxes@>;
+  while cur_v+leader_ht<=edge do
+    @<Output a leader box at |cur_v|,
+      then advance |cur_v| by |leader_ht|@>;
+@y
+  begin edge:=cur_v+rule_ht; lx:=0;
+  @<Let |cur_v| be the position of the first box, and set |leader_ht+lx|
+    to the spacing between corresponding parts of boxes@>;
+  while cur_v+leader_ht<=edge do
+    @<Output a leader box at |cur_v|,
+      then advance |cur_v| by |leader_ht+lx|@>;
+@z
+@x in module 636
+    leader_ht:=leader_ht+lx;
+@y
+@z
+@x in module 637
+cur_v:=save_v-height(leader_box)+leader_ht;
+@y
+cur_v:=save_v-height(leader_box)+leader_ht+lx;
+@z
+Also insert the following in modules 619 and 629:
+@!lx:scaled; {extra space between leader boxes}
+
+256. \/ should apply to ligatures! (August 20)
+@x in module 1113
+var f:internal_font_number; {the font in the |char_node|}
+begin if is_char_node(tail)and(tail<>head) then
+  begin f:=font(tail);
+  tail_append(new_kern(char_italic(f)(char_info(f)(character(tail)))));
+@y
+label exit;
+var p:pointer; {|char_node| at the tail of the current list}
+@!f:internal_font_number; {the font in the |char_node|}
+begin if tail<>head then
+  begin if is_char_node(tail) then p:=tail
+  else if type(tail)=ligature_node then p:=lig_char(tail)
+  else return;
+  f:=font(p);
+  tail_append(new_kern(char_italic(f)(char_info(f)(character(p)))));
+@z
+@x later in that same module
+end;
+@y
+exit: end;
+@z
+
+257. Another debugging hack. (August 27)
+@x module 1339
+15: begin font_in_short_display:=null_font; short_display(n);
+  end;
+@y
+15: begin font_in_short_display:=null_font; short_display(n);
+  end;
+16: panicking:=not panicking;
+@z
+
+258. Redundant code eliminated (August 27)
+Module 531 needn't set and reset name_in_progress [but it's harmless].
+
+259. Bug: \input shouldn't occur during font size spec (Spivak; fixed August 27)
+@x module 1258
+@ @<Scan the font size specification@>=
+@y
+@ @<Scan the font size specification@>=
+name_in_progress:=true; {this keeps |cur_name| from being changed}
+@z
+@x module 1258
+else s:=-1000
+@y
+else s:=-1000;
+name_in_progress:=false
+@z
+
+260. \ifhbox and \ifvbox introduced. (August 27)
+@x module 487
+@d ifx_code=10 { `\.{\\ifx}' }
+@d if_eof_code=11 { `\.{\\ifeof}' }
+@d if_true_code=12 { `\.{\\iftrue}' }
+@d if_false_code=13 { `\.{\\iffalse}' }
+@d if_case_code=14 { `\.{\\ifcase}' }
+@y
+@d if_hbox_code=10 { `\.{\\ifhbox}' }
+@d if_vbox_code=11 { `\.{\\ifvbox}' }
+@d ifx_code=12 { `\.{\\ifx}' }
+@d if_eof_code=13 { `\.{\\ifeof}' }
+@d if_true_code=14 { `\.{\\iftrue}' }
+@d if_false_code=15 { `\.{\\iffalse}' }
+@d if_case_code=16 { `\.{\\ifcase}' }
+@z
+@x
+primitive("ifx",if_test,ifx_code);
+@y
+primitive("ifhbox",if_test,if_hbox_code);
+@!@:if_hbox_}{\.{\\ifhbox} primitive@>
+primitive("ifvbox",if_test,if_vbox_code);
+@!@:if_vbox_}{\.{\\ifvbox} primitive@>
+primitive("ifx",if_test,ifx_code);
+@z
+@x module 488
+  ifx_code:print_esc("ifx");
+@y
+  if_hbox_code:print_esc("ifhbox");
+  if_vbox_code:print_esc("ifvbox");
+  ifx_code:print_esc("ifx");
+@z
+@x module 501
+if_void_code: @<Test if a box is void@>;
+@y
+if_void_code, if_hbox_code, if_vbox_code: @<Test box register status@>;
+@z
+@x module 505
+@ @<Test if a box is void@>=
+begin scan_eight_bit_int; b:=(box(cur_val)=null);
+end
+@y
+@ @<Test box register status@>=
+begin scan_eight_bit_int; p:=box(cur_val);
+if this_if=if_void_code then b:=(p=null)
+else if p=null then b:=false
+else if this_if=if_hbox_code then b:=(type(p)=hlist_node)
+else b:=(type(p)=vlist_node);
+end
+
+261. Serious data structure error (found by Todd Allen, August 29)
+@x module 478 (an error introduced in change 231)
+  q:=the_toks; link(p):=link(temp_head); p:=q;
+@y
+  q:=the_toks;
+  if link(temp_head)<>null then
+    begin link(p):=link(temp_head); p:=q;
+    end;
+@z
+
+262. Minor patch for efficiency (August 29)
+@x module 466
+    begin store_new_token(info(r)); r:=link(r);
+@y
+    begin fast_store_new_token(info(r)); r:=link(r);
+@z
+
+263. Minor patch to error message (August 29)
+@module 579
+  print(" has "); print_int(font_params[f]);
+  print(" fontdimen parameters");
+@.Font x has n fontdimen...@>
+@y
+  print(" has only "); print_int(font_params[f]);
+  print(" fontdimen parameters");
+@.Font x has only...@>
+@z
+
+*** The changes above comprise version 0.99999, used only at SAIL (August 29)
+
+264. funny blank spaces are showable (August 30)
+@x module 298
+spacer: print("blank space");
+@y
+spacer: chr_cmd("blank space ");
+@z
+
+265. \newlinechar [change 235] should affect print_char too (August 31)
+@x module 58
+procedure print_char(@!c:ascii_code); {prints a single character}
+begin case selector of
+term_and_log: begin wterm(xchr[c]); write(log_file,xchr[c]);
+  incr(term_offset); incr(file_offset);
+  if term_offset=max_print_line then
+    begin wterm_cr; term_offset:=0;
+    end;
+  if file_offset=max_print_line then
+    begin wlog_cr; file_offset:=0;
+    end;
+  end;
+log_only: begin write(log_file,xchr[c]); incr(file_offset);
+  if file_offset=max_print_line then print_ln;
+  end;
+term_only: begin wterm(xchr[c]); incr(term_offset);
+  if term_offset=max_print_line then print_ln;
+  end;
+no_print: do_nothing;
+pseudo: if tally<trick_count then trick_buf[tally mod error_line]:=c;
+new_string: begin if pool_ptr<pool_size then append_char(c);
+  end; {drop characters if the string space is full}
+othercases write(write_file[selector],xchr[c])
+endcases;@/
+incr(tally);
+end;
+@y
+procedure print_char(@!s:ascii_code); {prints a single character}
+label exit;
+begin if @<Character |s| is the current new-line character@> then
+ if selector<pseudo then
+  begin print_ln; return;
+  end;
+case selector of
+term_and_log: begin wterm(xchr[s]); wlog(xchr[s]);
+  incr(term_offset); incr(file_offset);
+  if term_offset=max_print_line then
+    begin wterm_cr; term_offset:=0;
+    end;
+  if file_offset=max_print_line then
+    begin wlog_cr; file_offset:=0;
+    end;
+  end;
+log_only: begin wlog(xchr[s]); incr(file_offset);
+  if file_offset=max_print_line then print_ln;
+  end;
+term_only: begin wterm(xchr[s]); incr(term_offset);
+  if term_offset=max_print_line then print_ln;
+  end;
+no_print: do_nothing;
+pseudo: if tally<trick_count then trick_buf[tally mod error_line]:=s;
+new_string: begin if pool_ptr<pool_size then append_char(s);
+  end; {drop characters if the string space is full}
+othercases write(write_file[selector],xchr[s])
+endcases;@/
+incr(tally);
+exit:end;
+
+266. \lastkern,\lastpenalty,\unkern,\unpenalty (September 4)
+@x module 208
+@d unskip=25 {nullify glue ( \.{\\unskip} )}
+@y
+@d remove_item=25 {nullify last item ( \.{\\unpenalty},
+  \.{\\unkern}, \.{\\unskip} )}
+@z
+@x module 208
+@d last_skip=69 {most recent glue ( \.{\\lastskip} )}
+@y
+@d last_item=69 {most recent item ( \.{\\lastpenalty},
+  \.{\\lastkern}, \.{\\lastskip} )}
+@z
+@x module 265
+primitive("lastskip",last_skip,0);@/
+@!@:last_skip_}{\.{\\lastskip} primitive@>
+@y
+@z
+@x module 265
+primitive("the",the,0);
+@!@:the_}{\.{\\the} primitive@>
+primitive("toks",toks_register,0);
+@!@:toks_}{\.{\\toks} primitive@>
+primitive("unskip",unskip,0);@/
+@!@:unskip_}{\.{\\unskip} primitive@>
+@y
+primitive("the",the,0);@/
+@!@:the_}{\.{\\the} primitive@>
+primitive("toks",toks_register,0);@/
+@!@:toks_}{\.{\\toks} primitive@>
+@z
+@x module 266
+last_skip: print_esc("lastskip");
+@y
+@z
+@x module 266
+unskip: print_esc("unskip");
+@y
+@z
+@x module 413
+last_skip: @<Fetch the glue in the current node, if any@>;
+@y
+last_item: @<Fetch an item in the current node, if appropriate@>;
+@z
+@x module 416 [I also changed the comment]
+primitive("dp",set_box_dimen,depth_offset);
+@!@:dp_}{\.{\\dp} primitive@>
+@y
+primitive("dp",set_box_dimen,depth_offset);
+@!@:dp_}{\.{\\dp} primitive@>
+primitive("lastpenalty",last_item,int_val);
+@!@:last_penalty_}{\.{\\lastpenalty} primitive@>
+primitive("lastkern",last_item,dimen_val);
+@!@:last_kern_}{\.{\\lastkern} primitive@>
+primitive("lastskip",last_item,glue_val);
+@!@:last_skip_}{\.{\\lastskip} primitive@>
+@z
+@x module 417
+else print_esc("dp");
+@y
+else print_esc("dp");
+last_item: if chr_code=int_val then print_esc("lastpenalty")
+else if chr_code=dimen_val then print_esc("lastkern")
+else print_esc("lastskip");
+@z
+@x module 424
+@ Here is where \.{\\lastskip} is implemented. The reference count will be
+updated later.
+@:last_skip_}{\.{\\lastskip} primitive@>
+
+@<Fetch the glue in the current node, if any@>=
+begin cur_val:=zero_glue; cur_val_level:=glue_val;
+if not is_char_node(tail)and(mode<>0) then
+  begin if type(tail)=glue_node then
+    begin cur_val:=glue_ptr(tail);
+    if subtype(tail)=mu_glue then cur_val_level:=mu_val;
+    end;
+  end
+else if (mode=vmode)and(tail=head)and(last_page_glue<>max_halfword) then
+  cur_val:=last_page_glue;
+end
+@y
+@ Here is where \.{\\lastpenalty}, \.{\\lastkern}, and \.{\\lastskip} are
+implemented. The reference count for \.{\\lastskip} will be updated later.
+
+@<Fetch an item in the current node...@>=
+begin if cur_chr=glue_val then cur_val:=zero_glue@+else cur_val:=0;
+cur_val_level:=cur_chr;
+if not is_char_node(tail)and(mode<>0) then
+  case cur_chr of
+  int_val: if type(tail)=penalty_node then cur_val:=penalty(tail);
+  dimen_val: if type(tail)=kern_node then cur_val:=width(tail);
+  glue_val: if type(tail)=glue_node then
+    begin cur_val:=glue_ptr(tail);
+    if subtype(tail)=mu_glue then cur_val_level:=mu_val;
+    end;
+  end {there are no other cases}
+else if (mode=vmode)and(tail=head) then
+  case cur_chr of
+  int_val: cur_val:=last_penalty;
+  dimen_val: cur_val:=last_kern;
+  glue_val: if last_glue<>max_halfword then cur_val:=last_glue;
+  end; {there are no other cases}
+end
+@z
+@x module 982 [also the comment changes]
+@!last_page_glue:pointer; {used to implement \.{\\lastskip}}
+@y
+@!last_glue:pointer; {used to implement \.{\\lastskip}}
+@!last_penalty:integer; {used to implement \.{\\lastpenalty}}
+@!last_kern:scaled; {used to implement \.{\\lastkern}}
+@z
+@x module 991
+last_page_glue:=max_halfword;
+@y
+last_glue:=max_halfword; last_penalty:=0; last_kern:=0;
+@z
+@x module 994
+@<Update the value of |last_page_glue|@>;
+@y
+@<Update the values of |last_glue|, |last_penalty|, and |last_kern|@>;
+@z
+@x module 996
+@ @<Update the value of |last_page_glue|@>=
+if last_page_glue<>max_halfword then delete_glue_ref(last_page_glue);
+if type(p)=glue_node then
+  begin last_page_glue:=glue_ptr(p); add_glue_ref(last_page_glue);
+  end
+else last_page_glue:=max_halfword
+@y
+@ @<Update the values of |last_glue|...@>=
+if last_glue<>max_halfword then delete_glue_ref(last_glue);
+last_penalty:=0; last_kern:=0;
+if type(p)=glue_node then
+  begin last_glue:=glue_ptr(p); add_glue_ref(last_glue);
+  end
+else  begin last_glue:=max_halfword;
+  if type(p)=penalty_node then last_penalty:=penalty(p)
+  else if type(p)=kern_node then last_kern:=width(p);
+  end
+@z
+@x module 1017
+if last_page_glue<>max_halfword then delete_glue_ref(last_page_glue);
+@<Start a new current page@>; {this sets |last_page_glue:=max_halfword|}
+@y
+if last_glue<>max_halfword then delete_glue_ref(last_glue);
+@<Start a new current page@>; {this sets |last_glue:=max_halfword|}
+@z
+@x module 1048
+vmode+vmove,hmode+hmove,mmode+hmove,any_mode(last_skip),
+@y
+vmode+vmove,hmode+hmove,mmode+hmove,any_mode(last_item),
+@z
+@x module 1104
+any_mode(unskip): delete_skip;
+@y
+any_mode(remove_item): delete_last;
+@z
+@x module 1105
+procedure delete_skip;
+var p:pointer; {runs through the current list}
+begin if (mode=vmode)and(tail=head) then
+  @<Apologize for inability to do \.{\\unskip} now,
+    unless the previous node was not glue@>
+else  begin if not is_char_node(tail) then if type(tail)=glue_node then
+@y
+procedure delete_last;
+var p:pointer; {runs through the current list}
+begin if (mode=vmode)and(tail=head) then
+  @<Apologize for inability to do the operation now,
+    unless \.{\\unskip} follows non-glue@>
+else  begin if not is_char_node(tail) then if type(tail)=cur_chr then
+@z
+@x module 1106
+@ @<Apologize for inability to do \.{\\unskip}...@>=
+begin if last_page_glue<>max_halfword then
+  begin you_cant;
+  help2("Sorry...I'm usually unable to take things from the current")@/
+    ("page. Try `I\vskip-\lastskip' instead."); error;
+@y
+@ @<Apologize for inability to do the operation...@>=
+begin if (cur_chr<>glue_node)or(last_glue<>max_halfword) then
+  begin you_cant;
+  help2("Sorry...I'm usually unable to take things from the current")@/
+    ("page. Try `I\vskip-\lastskip' instead.");
+  if cur_chr=kern_node then help_line[0]:=
+    ("page. Try `I\kern-\lastkern' instead.")
+  else if cur_chr<>glue_node then help_line[0]:=@|
+    ("page. Perhaps you can make the output routine do it.");
+  error;
+@z
+@x module 1107
+primitive("unhbox",un_hbox,box_code);@/
+@y
+primitive("unpenalty",remove_item,penalty_node);@/
+@!@:un_penalty_}{\.{\\unpenalty} primitive@>
+primitive("unkern",remove_item,kern_node);@/
+@!@:un_kern_}{\.{\\unkern} primitive@>
+primitive("unskip",remove_item,glue_node);@/
+@!@:un_skip_}{\.{\\unskip} primitive@>
+primitive("unhbox",un_hbox,box_code);@/
+@z
+@x module 1108
+un_hbox: if chr_code=copy_code then print_esc("unhcopy")
+@y
+remove_item: if chr_code=glue_node then print_esc("unskip")
+  else if chr_code=kern_node then print_esc("unkern")
+  else print_esc("unpenalty");
+un_hbox: if chr_code=copy_code then print_esc("unhcopy")
+@z
+
+*** The above changes installed in version 0.999999 (September 5, 1983)
+
+267. Undo change 29: it was overkill and not needed (Sep 17)
+@x module 1257
+label exit, common_ending;
+var u:pointer; {user's font identifier}
+@!s:scaled; {stated ``at'' size, or negative of scaled magnification}
+@!f:internal_font_number; {runs through existing fonts}
+begin if job_name=0 then open_log_file;
+  {avoid confusing \.{texput} with the font name}
+@<If the next token isn't a suitable control sequence, issue a complaint
+  and |return|; otherwise set |u:=cs_ptr|, and set |hash_used| to the
+  location of a ``frozen'' copy of the new font identifier@>;
+define(u,set_font,null_font); scan_optional_equals; scan_file_name;
+@<Scan the font size specification@>;
+@<If this font has already been loaded, set |f| to the internal
+  font number and |goto common_ending|@>;
+f:=read_font_info(u,cur_name,cur_area,s);
+common_ending: equiv(u):=f; geq_define(hash_used,set_font,f);
+font_ident[f]:=hash_used;
+exit:end;
+@y
+label common_ending;
+var u:pointer; {user's font identifier}
+@!s:scaled; {stated ``at'' size, or negative of scaled magnification}
+@!f:internal_font_number; {runs through existing fonts}
+begin if job_name=0 then open_log_file;
+  {avoid confusing \.{texput} with the font name}
+get_r_token; u:=cs_ptr;
+define(u,set_font,null_font); scan_optional_equals; scan_file_name;
+@<Scan the font size specification@>;
+@<If this font has already been loaded, set |f| to the internal
+  font number and |goto common_ending|@>;
+f:=read_font_info(u,cur_name,cur_area,s);
+common_ending: equiv(u):=f; font_ident[f]:=u;
+end;
+@z
+@x module 1260
+@ We reserve a special control sequence for the font identifier; this one
+cannot be redefined by the user, so it is safe to return it as a value of
+\.{\\the\\font}.
+
+@<If the next token isn't a suitable control sequence...@>=
+get_r_token;
+if cs_ptr<hash_base then
+  begin print_err("A font identifier must be a multiletter control sequence");
+@.A font identifier...@>
+  help2("You should say, e.g., `\font\ffn=fontfilename'.")@/
+  ("(I'm going to ignore the \font command you just gave.)");
+  back_error; return;
+  end;
+repeat if hash_is_full then overflow("hash size",hash_size);
+@:TeX capacity exceeded hash size}{\quad hash size@>
+decr(hash_used);
+until text(hash_used)=0; {search for an empty location in |hash|}
+u:=cs_ptr; text(hash_used):=text(u); {copy the name}
+@!stat incr(cs_count);@+tats@;@/
+@y
+@z
+Note: Since module 1260 has disappeared, module 1258 has been split into two.
+
+268. Minor change to diagnostic output format (September 18)
+@x module 211 [print_mode]
+  2:print("displayed math");
+@y
+  2:print("display math");
+@z
+
+269. Kerns inserted for accents must be explicit (September 20)
+@x module 1123
+@!p,@!q: pointer; {character and box nodes}
+@y
+@!p,@!q,@!r:pointer; {character, box, and kern nodes}
+@z
+@x module 1125
+link(tail):=new_kern(delta); link(link(tail)):=p;
+link(p):=new_kern(-a-delta); tail:=link(p); p:=q;
+@y
+r:=new_kern(delta); subtype(r):=explicit; link(tail):=r; link(r):=p;
+tail:=new_kern(-a-delta); subtype(tail):=explicit; link(p):=tail; p:=q;
+@z
+
+270. "log" changed to "transcript" in a few output messages (Sep 26)
+@x module 535
+prompt_file_name("log file name",".log");
+@y
+prompt_file_name("transcript file name",".log");
+@z
+@x module 1293
+      ("lists on your terminal as well as on the log file.");
+@y
+      ("lists on your terminal as well as in the transcript file.");
+@z
+@x module 1335
+  print_nl("(see the log file for additional information)");
+@.see the log file...@>
+@y
+  print_nl("(see the transcript file for additional information)");
+@.see the transcript file...@>
+@z
+
+271. Uninitialized variable bug (found by Bernd Schulze, 1 Oct 83)
+@x module 944
+    begin if trie_op_ptr>=max_quarterword-1 then {overflow}
+      begin trie_op_ptr:=max_quarterword;
+      new_trie_op:=min_quarterword; return;
+@y we allow one more trie op (OK since trie_op_hash_size is big enough)
+    begin if trie_op_ptr=max_quarterword then {overflow}
+      begin new_trie_op:=min_quarterword; return;
+@z
+
+272. Spaces at end of lines ignored also in TEX.POOL (by DRF, 14 Oct 83)
+@x module 52
+    begin if eoln(pool_file) then bad_pool('! TEX.POOL line too short.');
+@.TEX.POOL line too short@>
+    read(pool_file,m); append_char(xord[m]);
+@y
+    begin if eoln(pool_file) then m:=' '@+else read(pool_file,m);
+    append_char(xord[m]);
+@z
+
+273. |history| updates (by DRF, 14 Oct 83)
+@x module 77
+deletions_allowed:=true; history:=spotless; error_count:=0;
+@y
+deletions_allowed:=true; error_count:=0; {|history| is initialized elsewhere}
+@z
+@x module 1332
+@p begin {@!|start_here|}
+@y
+@p begin {@!|start_here|}
+history:=fatal_error_stop; {in case we quit during initialization}
+@z
+@x ibid.
+main_control; {come to life}
+@y
+history:=spotless; {ready to go!}
+main_control; {come to life}
+@z
+
+274. improved "runaway" messages (suggested by FY, October 18)
+@x module 305 (the introductory comment is changed too)
+@d aligning=4 {|scanner_status| when reading an alignment preamble}
+
+@<Glob...@>=
+@!scanner_status : normal..aligning; {can a subfile end now?}
+@y
+@d aligning=4 {|scanner_status| when reading an alignment preamble}
+@d absorbing=5 {|scanner_status| when reading a balanced text}
+
+@<Glob...@>=
+@!scanner_status : normal..absorbing; {can a subfile end now?}
+@z
+@x module 306 (string space is also now conserved slightly)
+  defining: begin print("definition?"); p:=def_ref;
+    end;
+  matching: begin print("argument?"); p:=temp_head;
+    end;
+  aligning: begin print("preamble?"); p:=hold_head;
+    end;
+  end; {there are no other cases}
+  print_ln; show_token_list(link(p),null,error_line-10);
+@y
+  defining: begin print("definition"); p:=def_ref;
+    end;
+  matching: begin print("argument"); p:=temp_head;
+    end;
+  aligning: begin print("preamble"); p:=hold_head;
+    end;
+  absorbing: begin print("text"); p:=def_ref;
+    end;
+  end; {there are no other cases}
+  print_char("?");print_ln; show_token_list(link(p),null,error_line-10);
+@x module 339 (I also changed the module name)
+end; {there are no other cases}
+@y
+absorbing:begin print("text"); info(p):=right_brace_token+"}";
+  end;
+end; {there are no other cases}
+@z
+@x module 473
+begin scanner_status:=defining; warning_index:=cs_ptr;
+def_ref:=get_avail; info(def_ref):=null;
+@y
+begin if macro_def then scanner_status:=defining
+@+else scanner_status:=absorbing;
+warning_index:=cs_ptr; def_ref:=get_avail; info(def_ref):=null;
+@z
+
+275. similar, but this corrects a real bug (found by FY, October 18)
+@x module 1226
+  cs_ptr:=q;
+  @<Get the next non-blank non-relax non-call token@>;
+  if cur_cmd<>left_brace then @<If the righthand side is a token parameter
+      or token register, finish the assignment and |goto done|@>;
+  back_input; q:=scan_toks(false,false);
+@y
+  @<Get the next non-blank non-relax non-call token@>;
+  if cur_cmd<>left_brace then @<If the righthand side is a token parameter
+      or token register, finish the assignment and |goto done|@>;
+  back_input; cs_ptr:=q; q:=scan_toks(false,false);
+@z
+
+276. Change #119 should have changed module 1090 too (by Barry Smith, Oct 24)
+@x module 1183 [which was module 1090 at the time of change 119]
+begin if c mod delimited_code=above_code then scan_normal_dimen;
+if c>=delimited_code then
+  begin scan_delimiter(garbage,false); scan_delimiter(garbage,false);
+  end;
+@y
+begin if c>=delimited_code then
+  begin scan_delimiter(garbage,false); scan_delimiter(garbage,false);
+  end;
+if c mod delimited_code=above_code then scan_normal_dimen;
+@z
+
+277. Changes for efficiency, based on empirical frequency data (Nov 9)
+@x module 45 [since the result is true almost always]
+begin j:=str_start[s]; result:=false;
+while j<str_start[s+1] do
+  begin if str_pool[j]<>buffer[k] then goto not_found;
+@y
+begin j:=str_start[s];
+while j<str_start[s+1] do
+  begin if str_pool[j]<>buffer[k] then
+    begin result:=false; goto not_found;
+    end;
+@z
+@x module 380 [many compilers don't handle "while true do" very well]
+label done;
+begin loop begin get_next;
+@^inner loop@>
+  if cur_cmd<=max_command then goto done;
+  if cur_cmd>=call then
+    if cur_cmd<end_template then macro_call
+    else  begin cs_ptr:=frozen_endv; cur_cmd:=endv;
+      goto done; {|cur_chr=null_list|}
+      end
+  else expand;
+  end;
+@y
+label restart,done;
+begin restart: get_next;
+@^inner loop@>
+if cur_cmd<=max_command then goto done;
+if cur_cmd>=call then
+  if cur_cmd<end_template then macro_call
+  else  begin cs_ptr:=frozen_endv; cur_cmd:=endv;
+    goto done; {|cur_chr=null_list|}
+    end
+else expand;
+goto restart;
+@z
+@x module 829 [preparation for change to module 852]
+label exit,done,continue,deactivate;
+@y
+label exit,done,done1,continue,deactivate;
+@z
+@x module 830 [ditto]
+@!save_link:pointer; {temporarily holds value of |link(cur_p)|}
+@y
+@!save_link:pointer; {temporarily holds value of |link(cur_p)|}
+@!shortfall:scaled; {used in badness calculations}
+@z
+@x modue 851 [ditto]
+if cur_active_width[1]<line_width then
+@y
+shortfall:=line_width-cur_active_width[1]; {we're this much too short}
+if shortfall>0 then
+@z
+@x module 852 [avoid calling |badness| in most common case]
+else  begin b:=badness(line_width-cur_active_width[1],cur_active_width[2]);
+@y
+else  begin if shortfall>7230584 then if cur_active_width[2]<1663497 then
+    begin b:=inf_bad; fit_class:=very_loose_fit; goto done1;
+    end;
+  b:=badness(shortfall,cur_active_width[2]);
+@z
+@x module 852, continued
+  else fit_class:=decent_fit;
+@y
+  else fit_class:=decent_fit;
+  done1:
+@z
+@x module 853 [using |shortfall|, since we now have it]
+begin if cur_active_width[1]-line_width>cur_active_width[6] then
+  b:=inf_bad+1
+else b:=badness(cur_active_width[1]-line_width,cur_active_width[6]);
+@y
+begin if -shortfall>cur_active_width[6] then b:=inf_bad+1
+else b:=badness(-shortfall,cur_active_width[6]);
+@z
+
+278. Forgotten |error| call (noticed by Gabi Kuper, December 3, 1983)
+@x module 500
+    help1("I'm ignoring this; it doesn't match any \if.");
+@y
+    help1("I'm ignoring this; it doesn't match any \if.");
+    error;
+@z
+
+*** Version 1.0 released on December 3, 1983 incorporates all of the above.
+Version 1.1
+
+279. Problem with change 267 (found by Mike Urban, received 2 Feb 84)
+(I had overlooked many problems, e.g. `{\font\a=x \global\a}\the\font'
+and `\font\a=x \font\b=x \let\b=\undefined \the\a', etc.
+The remedy involves removal of the font_ident array, so there's a
+sprinkling of corrections in lots of modules. But basically the change
+is quite conservative, so it shouldn't spawn any new bugs (it says here).)
+
+@x module 174 (removing a reference to |font_ident|)
+        else sprint_cs(font_ident[font(p)]);
+@y
+        else @<Print the font identifier for |font(p)|@>;
+@z
+@x module 176 (removing a reference to |font_ident|)
+  else sprint_cs(font_ident[font(p)]);
+@y
+  else @<Print the font identifier for |font(p)|@>;
+@z
+@x module 222 (redefining and expanding the `frozen' area)
+@d frozen_null_font=frozen_control_sequence+9 {permanent `\.{\\nullfont}'}
+@d frozen_dont_expand=frozen_control_sequence+10
+  {permanent `\.{\\notexpanded:}'}
+@d undefined_control_sequence=frozen_control_sequence+11 {dummy location}
+@y
+@d frozen_dont_expand=frozen_control_sequence+9
+  {permanent `\.{\\notexpanded:}'}
+@d frozen_null_font=frozen_control_sequence+10
+  {permanent `\.{\\nullfont}'}
+@d font_id_base=frozen_null_font-font_base
+  {begins table of 257 permanent font identifiers}
+@d undefined_control_sequence=frozen_null_font+257 {dummy location}
+@z
+@x module 234 (removing a reference to |font_ident|, awkwardly)
+print_char("="); sprint_cs(font_ident[equiv(n)]);
+@y
+print_char("=");@/
+print_esc(hash[font_id_base+equiv(n)].rh);
+  {that's |text(font_id_base+equiv(n))|}
+@z
+@x module 256 (adding a new macro, font_id_text)
+@d hash_is_full == (hash_used=hash_base) {test if all positions are occupied}
+@y
+@d hash_is_full == (hash_used=hash_base) {test if all positions are occupied}
+@d font_id_text(#) == text(font_id_base+#) {a frozen font identifier's name}
+@z
+@x module 262 (relaxing a former restriction)
+else if (text(p)<128)or(text(p)>=str_ptr) then print_esc("NONEXISTENT.")
+@y
+else if (text(p)<0)or(text(p)>=str_ptr) then print_esc("NONEXISTENT.")
+@z
+@x module 267 (pick up the changes from 174 and 176)
+@!@^Single-character primitives@>
+@y
+@!@^Single-character primitives@>
+
+Meanwhile, this is a convenient place to catch up on something we were unable
+to do before the hash table was defined:
+
+@<Print the font identifier for |font(p)|@>=
+print_esc(font_id_text(font(p)))
+@z
+@x module 415 (removing another reference to font_ident)
+  scanned_result(font_ident[cur_val])(ident_val);
+@y
+  scanned_result(font_id_base+cur_val)(ident_val);
+@z
+@x module 548 (change to the comment only)
+to the user's font~\.{\\f}. For example, if this internal number is 13,
+we will have |font_ident[13]=p| and |equiv(p)=13|, where |p| is the |eqtb|
+location of the control sequence~\.{\\f}.
+@y
+to the user's font~\.{\\f}. Adding this number to |font_id_base| gives the
+|eqtb| location of a ``frozen'' control sequence that will always select
+the font.
+@z
+@x module 549 (deleting the declaration of font_ident)
+@!font_ident:array[internal_font_number] of pointer; {the most recent user
+  font identifier corresponding to an internal font number}
+@y
+@z
+@x module 552 (deleting an unnecessary initialization of font_ident)
+font_ident[null_font]:=frozen_null_font;
+@y
+@z
+@x module 579 (removing another reference to font_ident)
+  begin print_err("Font "); sprint_cs(font_ident[f]);
+@y
+  begin print_err("Font "); print_esc(font_id_text(f));
+@z
+@x module 1257 (this is the real change!)
+begin if job_name=0 then open_log_file;
+  {avoid confusing \.{texput} with the font name}
+get_r_token; u:=cs_ptr;
+define(u,set_font,null_font); scan_optional_equals; scan_file_name;
+@<Scan the font size specification@>;
+@<If this font has already been loaded, set |f| to the internal
+  font number and |goto common_ending|@>;
+f:=read_font_info(u,cur_name,cur_area,s);
+common_ending: equiv(u):=f; font_ident[f]:=u;
+@y
+@!t:str_number; {name for the frozen font identifier}
+@!old_setting:0..max_selector; {holds |selector| setting}
+begin if job_name=0 then open_log_file;
+  {avoid confusing \.{texput} with the font name}
+get_r_token; u:=cs_ptr;
+if u>=hash_base then t:=text(u)
+else if u>=single_base then
+  if u=null_cs then t:="FONT"@+else t:=u-single_base
+else  begin old_setting:=selector; selector:=new_string;
+  print("FONT"); print(u-active_base); selector:=old_setting;
+@.FONTx@>
+  str_room(1); t:=make_string;
+  end;
+define(u,set_font,null_font); scan_optional_equals; scan_file_name;
+@<Scan the font size specification@>;
+@<If this font has already been loaded, set |f| to the internal
+  font number and |goto common_ending|@>;
+f:=read_font_info(u,cur_name,cur_area,s);
+common_ending: equiv(u):=f; eqtb[font_id_base+f]:=eqtb[u]; font_id_text(f):=t;
+@z
+@x module 1260 (change to the comment only)
+the new value becomes the |font_ident| of record. Font names `\.{xyz}' and
+@y
+the new name becomes the font identifier of record. Font names `\.{xyz}' and
+@z
+@x module 1322 (no need to dump font_ident)
+begin dump_int(font_ident[k]);
+dump_qqqq(font_check[k]);
+@y
+begin dump_qqqq(font_check[k]);
+@z
+@x module 1322 (or to print from it)
+print_nl("\font"); sprint_cs(font_ident[k]); print_char("=");
+@y
+print_nl("\font"); print_esc(font_id_text(k)); print_char("=");
+@z
+@x module 1323 (or to undump it)
+begin undump(active_base)(undefined_control_sequence)(font_ident[k]);
+undump_qqqq(font_check[k]);@/
+@y
+begin undump_qqqq(font_check[k]);@/
+@z
+
+280. Double interrupt possibility (found by Clint Cuzzo, received 9 Feb 84)
+@x module 1031
+if interrupt>0 then if OK_to_interrupt then
+  begin back_input; pause_for_instructions; goto big_switch;
+@y
+if interrupt<>0 then if OK_to_interrupt then
+  begin back_input; check_interrupt; goto big_switch;
+@z
+
+281. Improve spacing in $(A,<)$. (12 Feb 84)
+@x module 764
+"0234000122*4000133**3**344*0400400*000000234000111*4111112341011"
+@y
+"0234000122*4000133**3**344*0400400*000000234000111*1111112341011"
+@z
+
+282. Bad goto! (diagnosis by Clint Cuzzo and George O'Connor, recd 13 Feb 84)
+@x module 344 (here we simply change the name of module 346)
+any_state_plus(invalid_char): @<Decry the invalid character and
+  |goto switch|@>;
+@y
+any_state_plus(invalid_char): @<Decry the invalid character and
+  |goto restart|@>;
+@z
+@x module 346 (because clear_for_error_prompt might make state=token_list)
+goto switch;
+@y
+goto restart;
+@z
+
+283. String pool economy (suggested by DRF, 13 Feb 84)
+@x module 537
+@<Read the first line of the new file@>;
+@y
+if name=str_ptr-1 then {we can conserve string pool space now}
+  begin flush_string; name:=cur_name;
+  end;
+@<Read the first line of the new file@>;
+@z
+
+284. Nicer scaled output (suggested by METAFONT development, 26 Feb 84)
+@x module 103
+be reproduced exactly. [{\sl Proof:\/} If round$(x)=\lfloor
+x+{1\over2}\rfloor$ and if $\alpha<1$, it is not difficult to verify that
+round$(\alpha\,\hbox{round}( \alpha^{-1}n))=n$ for all integers |n|. In
+our case $\alpha=2^{16}/10^5$.]
+
+@p procedure print_scaled(@!s:scaled); {prints scaled real, rounded to five
+  digits}
+begin if s<0 then
+  begin print_char("-"); negate(s); {print the sign, if negative}
+  end;
+print_int(s div unity); {print the integer part}
+s:=((s mod unity) * 3125 + 1024) div 2048;
+  {now |0<=s<100000| is the fraction part}
+print_char(".");
+repeat print_char("0"+(s div 10000)); s:=10*(s mod 10000);
+until s=0;
+end;
+@y
+be reproduced exactly; the ``simplest'' such decimal number is output,
+but there is always at least one digit following the decimal point.
+
+The invariant relation in the \&{repeat} loop is that a sequence of
+decimal digits yet to be printed will yield the original number if and only if
+they form a fraction~$f$ in the range $s-\delta\L10\cdot2^{16}f<s$.
+We can stop if and only if $f=0$ satisfies this condition; the loop will
+terminate before $s$ can possibly become zero.
+
+@p procedure print_scaled(@!s:scaled); {prints scaled real, rounded to five
+  digits}
+var delta:scaled; {amount of allowable inaccuracy}
+begin if s<0 then
+  begin print_char("-"); negate(s); {print the sign, if negative}
+  end;
+print_int(s div unity); {print the integer part}
+print_char(".");
+s:=10*(s mod unity)+5; delta:=10;
+repeat if delta>unity then s:=s+@'100000-(delta div 2); {round the last digit}
+print_char("0"+(s div unity)); s:=10*(s mod unity); delta:=delta*10;
+until s<=delta;
+end;
+@z
+
+*** Those six changes account for version 1.1 (February 29, 1984).
+*** And we put the following change in too, at the last minute:
+
+285. ".00000762939453126pt" didn't round correctly! (March 2, 1984)
+@x module 452
+  if k<16 then {digits for |k>=16| cannot affect the result}
+@y (Note, I also changed the comment in module 102: 16 -> 17)
+  if k<17 then {digits for |k>=17| cannot affect the result}
+@z
+
+*** Note: I changed "cs_ptr" to "cur_cs", since the name change is more
+indicative of the fact that this variable makes a trio with cur_cmd
+and cur_chr. The TEX.WEB source changed 78 times, as a result, but
+none of the author's change files were affected.
+(But note: "save_cs_ptr" was not changed to "save_cur_cs", because
+of a name conflict.)
+
+*** And the following two were slipped in at the last second:
+
+286. loophole permitted get_next recursion (March 16, 1984)
+@x module 336
+  begin @<Back up an outer control sequence so that it can be reread@>;
+@y
+  begin deletions_allowed:=false;
+  @<Back up an outer control sequence so that it can be reread@>;
+@z
+@x ibid
+  end;
+@y
+  deletions_allowed:=true;
+  end;
+@z [the changes to deletions_allowed in module 338 can now be removed]
+
+287. terminal not open when the program starts bad (March 24, 1984)
+@x module 1332
+initialize; {set global variables to their starting values}
+@<Check the ``constant'' values...@>@;
+if bad>0 then
+  begin wake_up_terminal;
+  wterm('Ouch---my internal constants have been',
+    ' clobbered!---case ',bad:1);
+@.Ouch...clobbered@>
+  goto final_end;
+  end;
+@y
+@<Check the ``constant'' values...@>@;
+if bad>0 then
+  begin t_open_out;
+  wterm('Ouch---my internal constants have been',
+    ' clobbered!---case ',bad:1);
+@.Ouch...clobbered@>
+  goto final_end;
+  end;
+initialize; {set global variables to their starting values}
+@z
+
+*** Note: "Cosmetic" changes were also made in module 363 ("print_ln"
+moved to after "wake_up_terminal") and in some commentary.
+
+*** Another last-minute correction:
+288. \patterns{xxx...xxxdxxxdxxx} anomaly found by JRD (Mar 27, 1984)
+@x module 962
+else  begin hyf[k]:=cur_chr-"0"; digit_sensed:=true;
+@y
+else  begin hyf[k]:=cur_chr-"0";
+  if k<63 then digit_sensed:=true;
+@z
+
+*** Yoicks, yet ANOTHER:
+289. a whole case of copy_node_list forgotten (Apr 11, 1984)
+@x module 206
+othercases confusion("copying")
+@y
+adjust_node: begin r:=get_node(small_node_size);
+  adjust_ptr(r):=copy_node_list(adjust_ptr(p));
+  end; {|words=1=small_node_size-1|}
+othercases confusion("copying")
+@z
+
+*** And "finally"...
+290. uninitialized variables could be accessed (found by Nick Briggs, June 11)
+@x module 552
+font_size[null_font]:=0; font_dsize[null_font]:=0;
+@y
+font_size[null_font]:=0; font_dsize[null_font]:=0;
+char_base[null_font]:=0; width_base[null_font]:=0;
+height_base[null_font]:=0; depth_base[null_font]:=0;
+italic_base[null_font]:=0; lig_kern_base[null_font]:=0;
+kern_base[null_font]:=0; exten_base[null_font]:=0;
+@z (actual values are immaterial except for debugging safeguards)
+
+291. same, cf. modules 355 and 389 (Nick Briggs, June 11)
+@x module 331
+scanner_status:=normal; first:=1;
+@y
+for first:=0 to buf_size do buffer[first]:=0;
+scanner_status:=normal; warning_index:=null; first:=1;
+@z (error was harmless except that it might trigger debugging checks)
+
+292. missing ligature/kern (found by JRD, June 21)
+@x module 1036
+  if (cur_cmd=letter)or(cur_cmd=other_char) then r:=qi(cur_chr)
+@y
+  if (cur_cmd=letter)or(cur_cmd=other_char)or(cur_cmd=char_given) then
+    r:=qi(cur_chr)
+@z
+
+293. quarterword constraint is made explicit (July 4)
+@x module 111
+if (buf_size>max_halfword) then bad:=18;
+@y
+if buf_size>max_halfword then bad:=18;
+if max_quarterword-min_quarterword<255 then bad:=19;
+@z
+
+294. trivial optimization made for consistency with MF (July 7)
+@x module 363
+if (pausing>0)and(interaction>nonstop_mode) then
+@y
+if pausing>0 then if interaction>nonstop_mode then
+@z
+
+295. \tracingmacros>1 for more diagnostics (July 8)
+@x module 323
+  if t=macro then param_start:=param_ptr@+else loc:=link(p);
+@y
+  if t=macro then param_start:=param_ptr
+  else  begin loc:=link(p);
+    if tracing_macros>1 then
+      begin begin_diagnostic; print_nl("");
+      case t of
+      mark_text:print_esc("mark");
+      write_text:print_esc("write");
+      othercases print_cmd_chr(assign_toks,t-output_text+output_routine_loc)
+      endcases;@/
+      print("->"); token_show(p); end_diagnostic(false);
+      end;
+    end;
+@z
+
+*** The changes above were incorporated in Version 1.1, released July 9, 1984.
+Version 1.2
+
+296. "see the transcript file" on offline show commands. (July 27, 1984)
+@x module 1293
+@ @d show_error==@;@/
+  if interaction<error_stop_mode then
+    begin help0; decr(error_count);
+    end
+  else  if tracing_online>0 then
+      begin@t@>@;@/
+      help3("This isn't an error message; I'm just \showing something.")
+        @t\4\4@>@/
+      ("Type `I\show...' to show more (e.g., \show\cs,")@/
+      ("\showthe\count10, \showbox255, \showlists).");
+      end
+    else  begin@t@>@;@/
+      help5("This isn't an error message; I'm just \showing something.")
+        @t\4\4@>@/
+      ("Type `I\show...' to show more (e.g., \show\cs,")@/
+      ("\showthe\count10, \showbox255, \showlists).")@/
+      ("And type `I\tracingonline=1\show...' to show boxes and")@/
+      ("lists on your terminal as well as in the transcript file.");
+      end;
+  error
+
+@<Declare act...@>=
+procedure show_whatever;
+var p:pointer; {tail of a token list to show}
+begin case cur_chr of
+show_code: @<Show the current meaning of a token@>;
+show_box_code: @<Show the current contents of a box@>;
+show_the_code: @<Show the current value of some parameter or register@>;
+othercases @<Show the current semantic nest@>
+endcases;
+end;
+@y
+@ @<Declare act...@>=
+procedure show_whatever;
+label common_ending;
+var p:pointer; {tail of a token list to show}
+begin case cur_chr of
+show_lists: begin begin_diagnostic; show_activities;
+  end;
+show_box_code: @<Show the current contents of a box@>;
+show_code: @<Show the current meaning of a token, then |goto common_ending|@>;
+othercases @<Show the current value of some parameter or register,
+  then |goto common_ending|@>
+endcases;@/
+@<Complete a potentially long \.{\\show} command@>;
+common_ending: if interaction<error_stop_mode then
+  begin help0; decr(error_count);
+  end
+else if tracing_online>0 then
+  begin@t@>@;@/
+  help3("This isn't an error message; I'm just \showing something.")@/
+  ("Type `I\show...' to show more (e.g., \show\cs,")@/
+  ("\showthe\count10, \showbox255, \showlists).");
+  end
+else  begin@t@>@;@/
+  help5("This isn't an error message; I'm just \showing something.")
+  ("Type `I\show...' to show more (e.g., \show\cs,")@/
+  ("\showthe\count10, \showbox255, \showlists).")@/
+  ("And type `I\tracingonline=1\show...' to show boxes and")@/
+  ("lists on your terminal as well as in the transcript file.");
+  end;
+error;
+end;
+@z
+@x module 1294
+@ @<Show the current meaning of a token@>=
+begin get_token; print_nl("> ");
+if cur_cs<>0 then
+  begin sprint_cs(cur_cs); print_char("=");
+  end;
+print_meaning; show_error;
+@y
+@ @<Show the current meaning of a token...@>=
+begin get_token; print_nl("> ");
+if cur_cs<>0 then
+  begin sprint_cs(cur_cs); print_char("=");
+  end;
+print_meaning; goto common_ending;
+@z
+@x module 1296
+end_diagnostic(true);
+print_err("OK");
+@.OK@>
+show_error;
+@y
+@z
+@x module 1297
+flush_list(link(temp_head)); show_error;
+@y
+flush_list(link(temp_head)); goto common_ending;
+@z
+@x module 1298
+@ @<Show the current semantic nest@>=
+begin begin_diagnostic; show_activities; end_diagnostic(true);
+print_err("OK");
+show_error;
+@.OK@>
+end
+@y
+@ @<Complete a potentially long \.{\\show} command@>=
+end_diagnostic(true); print_err("OK");
+@.OK@>
+if selector=term_and_log then if tracing_online<=0 then
+  begin selector:=term_only; print(" (see the transcript file)");
+  selector:=term_and_log;
+  end
+@z
+
+297. allow `0' in response to error prompts (October 20, 1984)
+@x module 84
+"1","2","3","4","5","6","7","8","9": if deletions_allowed then
+@y
+"0","1","2","3","4","5","6","7","8","9": if deletions_allowed then
+@z
+Versions 1.3 and 1.4
+
+298. Dirty PASCAL (two quarterword 0's were read as a halfword) (25 Nov 84)
+@x module 846
+print(" -> @@@@"); print_int(serial(prev_break(passive)));
+@y
+print(" -> @@@@");
+if prev_break(passive)=null then print_char("0")
+else print_int(serial(prev_break(passive)));
+@z
+
+299. Ditto! (25 Nov 84)
+@x module 934
+label reswitch, exit, found, not_found;
+@y
+label reswitch, exit, found, not_found, done;
+@z
+@x module 939
+while info(p)>n-3 do {eliminate hyphens \TeX\ doesn't like}
+  begin q:=link(p); free_avail(p); p:=q;
+  end;
+@<Insert the \(p)pair |(s,p)| into the exception table@>;
+@y
+loop@+  begin if p=null then goto done;
+  if info(p)<n-2 then goto done;
+  q:=link(p); free_avail(p); p:=q; {eliminate hyphens that \TeX\ doesn't like}
+  end;
+done: @<Insert the \(p)pair |(s,p)| into the exception table@>;
+@z
+
+300. Major change to memory management (25 Nov 84)
+[The following changes have two main merits: (1) TeX should run faster on
+virtual-memory systems when the jobs are small; (2) it should be possible
+to use the same production version of TeX both for jobs with lots of macros
+and few boxes as well as for jobs with lots of boxes and few macros, because
+the boundary line between the two types of storage is now chosen dynamically.]
+[The user is unaffected, except that there's only one "memory size" overflow
+error now instead of two.]
+[The TRIP test is now changed slightly: The correct settings of memory
+size parameters are now mem_min=mem_bot=1, mem_top=mem_max=3000.]
+
+@x module 11
+@!mem_max=30000; {greatest index in \TeX's internal |mem| array;
+  must be strictly less than |max_halfword|}
+@y
+@!mem_max=30000; {greatest index in \TeX's internal |mem| array;
+  must be strictly less than |max_halfword|;
+  must be equal to |mem_top| in \.{INITEX}, otherwise |>=mem_top|}
+@!mem_min=0; {smallest index in \TeX's internal |mem| array;
+  must be |min_halfword| or more;
+  must be equal to |mem_bot| in \.{INITEX}, otherwise |<=mem_bot|}
+@z
+@x module 12
+@d mem_base=0 {smallest index in the |mem| array; must not be less
+  than |min_halfword|}
+@d hi_mem_base=13000 {smallest index in the single-word area of |mem|;
+  must be substantially larger than |mem_base| and smaller than |mem_max|}
+@y
+@d mem_bot=0 {smallest index in the |mem| array dumped by \.{INITEX};
+  must not be less than |mem_min|}
+@d mem_top==30000 {largest index in the |mem| array dumped by \.{INITEX};
+  must be substantially larger than |mem_bot|
+  and not greater than |mem_max|}
+@z
+@x module 12
+  about |(mem_max-hi_mem_base)/6|, but 2100 is already quite generous}
+@y
+  about |(mem_max-mem_min)/10|, but 2100 is already quite generous}
+@z
+@x module 14
+if (hi_mem_base<mem_base+100)or(hi_mem_base+100>mem_max) then bad:=4;
+@y
+if mem_bot+1100>mem_top then bad:=4;
+@z
+@x module 111
+if (min_quarterword>0)or(max_quarterword<127) then bad:=11;
+@y
+init if (mem_min<>mem_bot)or(mem_max<>mem_top) then bad:=10;@+tini@;@/
+if (mem_min>mem_bot)or(mem_max<mem_top) then bad:=10;
+if (min_quarterword>0)or(max_quarterword<127) then bad:=11;
+@z
+@x module 111
+if (mem_base<min_halfword)or(mem_max>=max_halfword) then bad:=14;
+@y
+if (mem_min<min_halfword)or(mem_max>=max_halfword) then bad:=14;
+@z
+@x module 115
+value represents a null pointer.
+
+@d pointer==halfword {a flag or a location in |mem| or |eqtb|}
+@d null==mem_base {the null pointer}
+@y
+value represents a null pointer. \TeX\ does not assume that |mem[null]| exists.
+
+@d pointer==halfword {a flag or a location in |mem| or |eqtb|}
+@d null==min_halfword {the null pointer}
+@z
+@x module 116
+@ The |mem| array is divided once and for all into two regions that are
+allocated separately. Locations less than |hi_mem_base| are used for storing
+@y
+@ The |mem| array is divided into two regions that are allocated separately,
+but the dividing line between these two regions is not fixed; they grow
+together until finding their ``natural'' size in a particular job.
+Locations less than or equal to |lo_mem_max| are used for storing
+@z
+@x module 116
+relevant size when a node is freed. The remaining region of |mem| is
+allocated in single words using a conventional \.{AVAIL} stack.
+
+Incidentally, it would be feasible to construct implementations of \TeX\ that
+are based on 16-bit words instead of 32-bit words, for machines having
+comparatively small memories. In such cases it might be desirable to have
+two parallel arrays for the upper part of memory, called say \\{mem\_link}|[p]|
+and \\{mem\_info}|[p]|,
+since the single-word region in the present implementation
+consists entirely of |memory_word| items of type |two_halves|.
+@^small computers@>
+@y
+relevant size when a node is freed. Locations greater than or equal to
+|hi_mem_min| are used for storing one-word records; a conventional
+\.{AVAIL} stack is used for allocation in this region.
+
+Locations of |mem| between |mem_bot| and |mem_top| may be dumped as part
+of preloaded format files, by the \.{INITEX} preprocessor.
+@.INITEX@>
+Production versions of \TeX\ may extend the memory at both ends in order to
+provide more space; locations between |mem_min| and |mem_bot| are always
+used for variable-size nodes, and locations between |mem_top| and |mem_max|
+are always used for single-word nodes.
+
+The key pointers that govern |mem| allocation have a prescribed order:
+$$\hbox{|null<=mem_min<=mem_bot<lo_mem_max<
+  hi_mem_min<mem_top<=mem_end<=mem_max|.}$$
+@z
+@x module 116
+@!mem : array[mem_base..mem_max] of memory_word; {the big dynamic storage area}
+@y
+@!mem : array[mem_min..mem_max] of memory_word; {the big dynamic storage area}
+@!lo_mem_max : pointer; {the largest location of variable-size memory in use}
+@!hi_mem_min : pointer; {the smallest location of one-word memory in use}
+@z
+@x module 117
+@!max_var_used : integer; {how much memory was in use}
+@y
+@z
+@x module 118
+occur between |hi_mem_base| and |mem_end|, inclusive, are of type
+@y
+occur between |hi_mem_min| and |mem_end|, inclusive, are of type
+@z
+@x module 120
+else  begin runaway; {if memory is exhausted, display possible runaway text}
+  overflow("macro memory size",mem_max+1-hi_mem_base);
+    {quit; all one-word nodes are busy}
+@:TeX capacity exceeded macro memory size}{\quad macro memory size@>
+  end;
+@y
+else   begin decr(hi_mem_min); p:=hi_mem_min;
+  if hi_mem_min<=lo_mem_max then
+    begin runaway; {if memory is exhausted, display possible runaway text}
+    overflow("main memory size",mem_max+1-mem_min);
+      {quit; all one-word nodes are busy}
+@:TeX capacity exceeded main memory size}{\quad main memory size@>
+    end;
+  end;
+@z
+@x module 125
+label found,exit;
+@y
+label found,exit,restart;
+@z
+@x module 125
+begin p:=rover; {start at some free node in the ring}
+@y
+begin restart: p:=rover; {start at some free node in the ring}
+@z
+@x module 125
+overflow("box memory size",hi_mem_base-mem_base);
+  {sorry, nothing satisfactory is left}
+@:TeX capacity exceeded box memory size}{\quad box memory size@>
+found: link(r):=null; {this node is now nonempty}
+@!stat var_used:=var_used+s; {maintain usage statistics}
+if var_used>max_var_used then max_var_used:=var_used;
+@y
+if lo_mem_max+2<hi_mem_min then
+  @<Grow more variable-size memory and |goto restart|@>;
+overflow("main memory size",mem_max+1-mem_min);
+  {sorry, nothing satisfactory is left}
+@:TeX capacity exceeded main memory size}{\quad main memory size@>
+found: link(r):=null; {this node is now nonempty}
+@!stat var_used:=var_used+s; {maintain usage statistics}
+@z
+@x modules 126--127
+@ Empirical tests show that the routine in this section performs a
+|remove_node| operation about 0.75 times per allocation, on the average,
+after which it finds that |r>p+1| about 95\% of the time.
+
+@<Try to allocate...@>=
+q:=p+node_size(p); {find the physical successor}
+@^inner loop@>
+while is_empty(q) do @<Merge node |p| with node |q|@>;
+r:=q-s;
+if r>p+1 then @<Allocate from the top of node |p| and |goto found|@>;
+if r=p then if ((rlink(p)<>rover) or (llink(p)<>rover)) then
+  @<Allocate entire node |p| and |goto found|@>;
+node_size(p):=q-p {reset the size in case it grew}
+
+@ @<Merge node |p| with node |q|@>=
+begin t:=rlink(q);
+@^inner loop@>
+if q=rover then rover:=t;
+llink(t):=llink(q); rlink(llink(q)):=t;@/
+q:=q+node_size(q);
+end
+@y
+@ The lower part of |mem| grows by 1000 words at a time, unless
+we are very close to going under. When it grows, we simply link
+a new node into the available-space list. This method of controlled
+growth helps to keep the |mem| usage consecutive when \TeX\ is
+implemented on ``virtual memory'' systems.
+@^virtual memory@>
+
+@<Grow more variable-size memory and |goto restart|@>=
+begin if lo_mem_max+1000<hi_mem_min then t:=lo_mem_max+1000
+else t:=(lo_mem_max+hi_mem_min+2) div 2; {|lo_mem_max+2<=t<hi_mem_min|}
+p:=llink(rover); q:=lo_mem_max; rlink(p):=q; llink(rover):=q;@/
+rlink(q):=rover; llink(q):=p; link(q):=empty_flag; node_size(q):=t-lo_mem_max;@/
+lo_mem_max:=t; link(lo_mem_max):=null; info(lo_mem_max):=null;
+rover:=q; goto restart;
+end
+
+@ Empirical tests show that the routine in this section performs a
+node-merging operation about 0.75 times per allocation, on the average,
+after which it finds that |r>p+1| about 95\% of the time.
+
+@<Try to allocate...@>=
+q:=p+node_size(p); {find the physical successor}
+@^inner loop@>
+while is_empty(q) do {merge node |p| with node |q|}
+  begin t:=rlink(q);
+  if q=rover then rover:=t;
+  llink(t):=llink(q); rlink(llink(q)):=t;@/
+  q:=q+node_size(q);
+  end;
+r:=q-s;
+if r>p+1 then @<Allocate from the top of node |p| and |goto found|@>;
+if r=p then if ((rlink(p)<>rover) or (llink(p)<>rover)) then
+  @<Allocate entire node |p| and |goto found|@>;
+node_size(p):=q-p {reset the size in case it grew}
+@z
+% module 129 no longer refers to remove_node; I don't recall when it changed!
+@x module 134
+@d is_char_node(#) == (#>hi_mem_base)
+@y
+@d is_char_node(#) == (#>=hi_mem_min)
+@z
+@x module 162
+example, locations |mem_base| to |mem_base+3| are always used to store the
+specification for glue that is `\.{0pt plus 0pt minus 0pt}'. The
+following macro definitions accomplish the static allocation by giving
+symbolic names to the fixed positions. Dynamic allocation of variable-size
+nodes is restricted to locations |first_mem| through |(hi_mem_base-1)|,
+and single-word nodes are dynamically allocated in locations |second_mem|
+through |mem_max|, inclusive. It is harmless to let |lig_trick|, |garbage|,
+and |backup_head| share the same location of |mem|.
+
+@d zero_glue==mem_base {specification for \.{0pt plus 0pt minus 0pt}}
+@y
+example, locations |mem_bot| to |mem_bot+3| are always used to store the
+specification for glue that is `\.{0pt plus 0pt minus 0pt}'. The
+following macro definitions accomplish the static allocation by giving
+symbolic names to the fixed positions. Static variable-size nodes appear
+in locations |mem_bot| through |lo_mem_stat_max|, and static single-word nodes
+appear in locations |hi_mem_stat_min| through |mem_top|, inclusive. It is
+harmless to let |lig_trick|, |garbage|, and |backup_head| share the same
+location of |mem|.
+
+@d zero_glue==mem_bot {specification for \.{0pt plus 0pt minus 0pt}}
+@z
+@x module 162
+@d first_mem==fil_neg_glue+glue_spec_size {first dynamically allocatable word
+  in the variable-size |mem|}
+@#
+@d page_ins_head==hi_mem_base {list of insertion data for current page}
+@d contrib_head==hi_mem_base+1 {vlist of items not yet on current page}
+@d page_head==hi_mem_base+2 {vlist for current page}
+@d temp_head==hi_mem_base+3 {head of a temporary list of some kind}
+@d hold_head==hi_mem_base+4 {head of a temporary list of another kind}
+@d adjust_head==hi_mem_base+5 {head of adjustment list returned by |hpack|}
+@d active==hi_mem_base+6 {head of active list in |line_break|, needs two words}
+@d align_head==hi_mem_base+8 {head of preamble list for alignments}
+@d end_span==hi_mem_base+9 {tail of spanned-width lists}
+@d omit_template==hi_mem_base+10 {a constant token list}
+@d null_list==hi_mem_base+11 {permanently empty list}
+@d lig_trick==hi_mem_base+12 {a ligature masquerading as a |char_node|}
+@d garbage==hi_mem_base+12 {used for scrap information}
+@d backup_head==hi_mem_base+13 {head of token list built by |scan_keyword|}
+@d second_mem==hi_mem_base+14 {first dynamically allocatable word in
+  the one-word |mem|}
+@y
+@d lo_mem_stat_max==fil_neg_glue+glue_spec_size-1 {largest statically
+  allocated word in the variable-size |mem|}
+@#
+@d page_ins_head==mem_top {list of insertion data for current page}
+@d contrib_head==mem_top-1 {vlist of items not yet on current page}
+@d page_head==mem_top-2 {vlist for current page}
+@d temp_head==mem_top-3 {head of a temporary list of some kind}
+@d hold_head==mem_top-4 {head of a temporary list of another kind}
+@d adjust_head==mem_top-5 {head of adjustment list returned by |hpack|}
+@d active==mem_top-6 {head of active list in |line_break|, needs two words}
+@d align_head==mem_top-8 {head of preamble list for alignments}
+@d end_span==mem_top-9 {tail of spanned-width lists}
+@d omit_template==mem_top-10 {a constant token list}
+@d null_list==mem_top-11 {permanently empty list}
+@d lig_trick==mem_top-12 {a ligature masquerading as a |char_node|}
+@d garbage==mem_top-12 {used for scrap information}
+@d backup_head==mem_top-13 {head of token list built by |scan_keyword|}
+@d hi_mem_stat_min==mem_top-13 {smallest statically allocated word in
+  the one-word |mem|}
+@z
+@x module 164
+for k:=mem_base+1 to first_mem-1 do mem[k].sc:=0;
+  {all glue dimensions are zeroed}
+@^data structure assumptions@>
+k:=mem_base;@+while k<first_mem do {set first words of glue specifications}
+@y
+for k:=mem_bot+1 to lo_mem_stat_max do mem[k].sc:=0;
+  {all glue dimensions are zeroed}
+@^data structure assumptions@>
+k:=mem_bot;@+while k<=lo_mem_stat_max do
+    {set first words of glue specifications}
+@z
+@x module 164
+rover:=first_mem; link(rover):=empty_flag; {now initialize the dynamic memory}
+node_size(rover):=hi_mem_base-rover; {which is one big available node}
+llink(rover):=rover; rlink(rover):=rover;@/
+link(hi_mem_base):=null; info(hi_mem_base):=null;
+for k:=hi_mem_base+1 to second_mem-1 do
+  mem[k]:=mem[hi_mem_base];{clear list heads}
+@<Initialize the special list heads and constant nodes@>;
+avail:=null; mem_end:=second_mem-1; {initialize the one-word memory}
+var_used:=first_mem-mem_base; dyn_used:=second_mem-hi_mem_base;
+max_var_used:=var_used; {initialize statistics}
+@y
+rover:=lo_mem_stat_max+1;
+link(rover):=empty_flag; {now initialize the dynamic memory}
+node_size(rover):=1000; {which is a 1000-word available node}
+llink(rover):=rover; rlink(rover):=rover;@/
+lo_mem_max:=rover+1000; link(lo_mem_max):=null; info(lo_mem_max):=null;@/
+for k:=hi_mem_stat_min to mem_top do
+  mem[k]:=mem[lo_mem_max]; {clear list heads}
+@<Initialize the special list heads and constant nodes@>;
+avail:=null; mem_end:=mem_top;
+hi_mem_min:=hi_mem_stat_min; {initialize the one-word memory}
+var_used:=lo_mem_stat_max+1-mem_bot; dyn_used:=mem_top+1-hi_mem_stat_min;
+  {initialize statistics}
+@z
+@x module 165
+@t\hskip1em@>@!was_mem_end: pointer; {previous |mem_end|}
+@y
+@t\hskip1em@>@!was_mem_end,@!was_lo_max,@!was_hi_min: pointer;
+  {previous |mem_end|, |lo_mem_max|,and |hi_mem_min|}
+@z
+@x module 166
+@!debug was_mem_end:=mem_base; {indicate that everything was previously free}
+@y
+@!debug was_mem_end:=mem_min; {indicate that everything was previously free}
+was_lo_max:=mem_min; was_hi_min:=mem_max;
+@z
+@x module 167
+begin for p:=mem_base to mem_end do free[p]:=false; {you can probably
+  do this faster}
+@y
+begin for p:=mem_min to lo_mem_max do free[p]:=false; {you can probably
+  do this faster}
+for p:=hi_mem_min to mem_end do free[p]:=false; {ditto}
+@z
+@x module 167
+for p:=0 to mem_end do was_free[p]:=free[p]; {|was_free:=free| might be faster}
+was_mem_end:=mem_end;
+@y
+for p:=mem_min to lo_mem_max do was_free[p]:=free[p];
+for p:=hi_mem_min to mem_end do was_free[p]:=free[p];
+  {|was_free:=free| might be faster}
+was_mem_end:=mem_end; was_lo_max:=lo_mem_max; was_hi_min:=hi_mem_min;
+@z
+@x module 168
+  begin if (p>mem_end)or(p<second_mem) then clobbered:=true
+@y
+  begin if (p>mem_end)or(p<hi_mem_min) then clobbered:=true
+@z
+@x module 169
+repeat if (p>=hi_mem_base)or(p<first_mem) then clobbered:=true
+  else if (rlink(p)>=hi_mem_base)or(rlink(p)<first_mem) then clobbered:=true
+  else if  not(is_empty(p))or(node_size(p)<2)or@|
+   (p+node_size(p)>hi_mem_base)or@| (llink(rlink(p))<>p) then clobbered:=true;
+@y
+repeat if (p>=lo_mem_max)or(p<mem_min) then clobbered:=true
+  else if (rlink(p)>=lo_mem_max)or(rlink(p)<mem_min) then clobbered:=true
+  else if  not(is_empty(p))or(node_size(p)<2)or@|
+   (p+node_size(p)>lo_mem_max)or@| (llink(rlink(p))<>p) then clobbered:=true;
+@z
+@x module 170
+p:=mem_base;
+while p<=hi_mem_base do {node |p| should not be empty}
+@y
+p:=mem_min;
+while p<=lo_mem_max do {node |p| should not be empty}
+@z
+@x module 170
+  while (p<=hi_mem_base) and not free[p] do incr(p);
+  while (p<=hi_mem_base) and free[p] do incr(p);
+@y
+  while (p<=lo_mem_max) and not free[p] do incr(p);
+  while (p<=lo_mem_max) and free[p] do incr(p);
+@z
+@x module 171
+for p:=mem_base to mem_end do
+  if not free[p] and ((p>was_mem_end) or was_free[p]) then
+@y
+for p:=mem_min to lo_mem_max do
+  if not free[p] and ((p>was_lo_max) or was_free[p]) then
+    begin print_char(" "); print_int(p);
+    end;
+for p:=hi_mem_min to mem_end do
+  if not free[p] and
+   ((p<was_hi_min) or (p>was_mem_end) or was_free[p]) then
+@z
+@x module 172
+begin for q:=mem_base to mem_end do
+@y
+begin for q:=mem_min to lo_mem_max do
+@z
+@x module 172
+@<Search |eqtb| for equivalents equal to |p|@>;
+@y
+for q:=hi_mem_min to mem_end do
+  begin if link(q)=p then
+    begin print_nl("LINK("); print_int(q); print_char(")");
+    end;
+  if info(q)=p then
+    begin print_nl("INFO("); print_int(q); print_char(")");
+    end;
+  end;
+@<Search |eqtb| for equivalents equal to |p|@>;
+@z
+@x module 176
+if (p<hi_mem_base)or(p>mem_end) then print_esc("CLOBBERED.")
+@y
+if (p<hi_mem_min)or(p>mem_end) then print_esc("CLOBBERED.")
+@z
+@x module 178
+begin if (p<mem_base)or(p>=hi_mem_base) then print_char("*")
+@y
+begin if (p<mem_min)or(p>=lo_mem_max) then print_char("*")
+@z
+@x module 293
+if (p<hi_mem_base) or (p>mem_end) then
+@y
+if (p<hi_mem_min) or (p>mem_end) then
+@z
+@x module 639
+  print_int(dyn_used); print("; max so far: ");
+  print_int(max_var_used); print_char("&");
+  print_int(mem_end+1-hi_mem_base); print_ln;
+@y
+  print_int(dyn_used); print("; still untouched: ");
+  print_int(hi_mem_min-lo_mem_max-1); print_ln;
+@z
+@x module 857
+begin save_link:=link(cur_p); {this is OK even if |cur_p=null|}
+link(cur_p):=null; print_nl(""); short_display(link(printed_node));
+link(cur_p):=save_link; printed_node:=cur_p;
+@y
+begin print_nl("");
+if cur_p=null then short_display(link(printed_node))
+else  begin save_link:=link(cur_p);
+  link(cur_p):=null; print_nl(""); short_display(link(printed_node));
+  link(cur_p):=save_link;
+  end;
+printed_node:=cur_p;
+@z
+@x module 1249
+if 2*max_halfword<hi_mem_base-mem_base then bad:=41;
+@y
+if 2*max_halfword<mem_top-mem_min then bad:=41;
+@z
+@x module 1307
+dump_int(hi_mem_base);@/
+@y
+dump_int(mem_bot);@/
+dump_int(mem_top);@/
+@z
+@x module 1308
+if x<>hi_mem_base then goto bad_fmt;
+@y
+if x<>mem_bot then goto bad_fmt;
+undump_int(x);
+if x<>mem_top then goto bad_fmt;
+@z
+@x module 1311
+dump_int(rover);
+p:=mem_base; q:=rover; x:=0;
+@y
+dump_int(lo_mem_max); dump_int(rover);
+p:=mem_bot; q:=rover; x:=0;
+@z
+@x module 1311
+var_used:=var_used+hi_mem_base-p; dyn_used:=mem_end+1-hi_mem_base;@/
+dump_int(mem_end); dump_int(avail);
+for k:=p to mem_end do dump_wd(mem[k]);
+x:=x+mem_end+1-p;
+@y
+var_used:=var_used+lo_mem_max-p; dyn_used:=mem_end+1-hi_mem_min;@/
+for k:=p to lo_mem_max do dump_wd(mem[k]);
+x:=x+lo_mem_max+1-p;
+dump_int(hi_mem_min); dump_int(avail);
+for k:=hi_mem_min to mem_end do dump_wd(mem[k]);
+x:=x+mem_end+1-hi_mem_min;
+@z
+@x module 1312
+undump(min_halfword)(hi_mem_base)(rover);
+p:=mem_base; q:=rover; x:=0;
+repeat for k:=p to q+1 do undump_wd(mem[k]);
+p:=q+node_size(q);
+if (p>hi_mem_base)or((q>=rlink(q))and(rlink(q)<>rover)) then goto bad_fmt;
+q:=rlink(q);
+until q=rover;
+undump_size(hi_mem_base)(mem_max)('mem max')(mem_end);
+undump(null)(mem_end)(avail);
+for k:=p to mem_end do undump_wd(mem[k]);
+undump_int(var_used); undump_int(dyn_used);
+max_var_used:=var_used
+@y
+undump(lo_mem_stat_max+1000)(hi_mem_stat_min-1)(lo_mem_max);
+undump(lo_mem_stat_max+1)(lo_mem_max)(rover);
+p:=mem_bot; q:=rover; x:=0;
+repeat for k:=p to q+1 do undump_wd(mem[k]);
+p:=q+node_size(q);
+if (p>lo_mem_max)or((q>=rlink(q))and(rlink(q)<>rover)) then goto bad_fmt;
+q:=rlink(q);
+until q=rover;
+for k:=p to lo_mem_max do undump_wd(mem[k]);
+if mem_min<mem_bot-2 then {make more low memory available}
+  begin p:=llink(rover); q:=mem_min+1;
+  link(mem_min):=null; info(mem_min):=null; {we don't use the bottom word}
+  rlink(p):=q; llink(rover):=q;@/
+  rlink(q):=rover; llink(q):=p; link(q):=empty_flag;
+  node_size(q):=mem_bot-q;
+  end;
+undump(lo_mem_max+1)(hi_mem_stat_min)(hi_mem_min);
+undump(null)(mem_top)(avail); mem_end:=mem_top;
+for k:=hi_mem_min to mem_end do undump_wd(mem[k]);
+undump_int(var_used); undump_int(dyn_used)
+@z
+@x module 1323
+undump(min_halfword)(hi_mem_base)(font_glue[k]);
+@y
+undump(min_halfword)(lo_mem_max)(font_glue[k]);
+@z
+@x module 1334
+  wlog_ln(' ',max_var_used:1,'&',mem_end+1-hi_mem_base:1,@|
+    ' words of memory out of ',
+    hi_mem_base-mem_base:1,'&',mem_max+1-hi_mem_base:1);@/
+@y
+  wlog_ln(' ',lo_mem_max-mem_min+mem_end-hi_mem_min+2:1,@|
+    ' words of memory out of ',mem_end+1-mem_min:1);@/
+@z that's the end of change number 300!
+
+301. node_size field could overflow if low mem was too large (Dec 20, 1984)
+[This bug existed from the beginning, if hi_mem_base-first_mem>max_halfword!]
+@x module 111
+if (mem_min<min_halfword)or(mem_max>=max_halfword) then bad:=14;
+@y
+if (mem_min<min_halfword)or(mem_max>=max_halfword)or@|
+  (mem_bot-mem_min>max_halfword+1) then bad:=14;
+@z
+@x module 125
+@!t:pointer; {temporary register}
+@y
+@!t:integer; {temporary register}
+@z
+@x module 125
+if lo_mem_max+2<hi_mem_min then
+@y
+if lo_mem_max+2<hi_mem_min then if lo_mem_max+2<=mem_bot+max_halfword then
+@z
+@x module 126
+rlink(q):=rover; llink(q):=p; link(q):=empty_flag; node_size(q):=t-lo_mem_max;@/
+@y
+if t>mem_bot+max_halfword then t:=mem_bot+max_halfword;
+rlink(q):=rover; llink(q):=p; link(q):=empty_flag; node_size(q):=t-lo_mem_max;@/
+@z
+
+302. Improvement to missing-format-file error (DRF, 5 Jan 85)
+@x module 524
+var j:0..buf_size; {the first space after the file name}
+begin if buffer[loc]="&" then
+  begin incr(loc); j:=loc; buffer[last]:=" ";
+  while buffer[j]<>" " do incr(j);
+  pack_buffered_name(0,loc,j-1); {try first without the system file area}
+  if w_open_in(fmt_file) then
+    begin loc:=j; goto found;
+    end;@/
+  pack_buffered_name(format_area_length,loc,j-1);
+    {now try the system format file area}
+  if w_open_in(fmt_file) then
+    begin loc:=j; goto found;
+    end;
+  wake_up_terminal;
+  wterm_ln('Sorry, I can''t find that format;',' will try PLAIN.');
+@.Sorry, I can't find...@>
+  end;
+  {now pull out all the stops: try for the system \.{PLAIN} file}
+pack_buffered_name(format_default_length-format_ext_length,1,0);
+if not w_open_in(fmt_file) then
+  begin wake_up_terminal;
+  wterm_ln('I can''t find the PLAIN format file!');
+@.I can't find PLAIN...@>
+@.PLAIN@>
+  open_fmt_file:=false; return;
+  end;
+found:open_fmt_file:=true;
+@y
+var j:0..buf_size; {the first space after the format file name}
+begin j:=loc;
+if buffer[loc]="&" then
+  begin incr(loc); j:=loc; buffer[last]:=" ";
+  while buffer[j]<>" " do incr(j);
+  pack_buffered_name(0,loc,j-1); {try first without the system file area}
+  if w_open_in(fmt_file) then goto found;
+  pack_buffered_name(format_area_length,loc,j-1);
+    {now try the system format file area}
+  if w_open_in(fmt_file) then goto found;
+  wake_up_terminal;
+  wterm_ln('Sorry, I can''t find that format;',' will try PLAIN.');
+@.Sorry, I can't find...@>
+  update_terminal;
+  end;
+  {now pull out all the stops: try for the system \.{PLAIN} file}
+pack_buffered_name(format_default_length-format_ext_length,1,0);
+if not w_open_in(fmt_file) then
+  begin wake_up_terminal;
+  wterm_ln('I can''t find the PLAIN format file!');
+@.I can't find PLAIN...@>
+@.PLAIN@>
+  open_fmt_file:=false; return;
+  end;
+found:loc:=j; open_fmt_file:=true;
+@z
+
+303. Welcoming message appears sooner (DRF, Jan 7)
+@x module 61
+else  begin print(format_ident); print_ln;
+  end;
+@y
+else  begin print(format_ident); print_ln;
+  end;
+update_terminal;
+@z
+
+304. Minor change to help message in "confusion" (Jan 23)
+@x module 95
+  help2("One of your earlier faux pas has wounded me deeply,")@/
+    ("so I'm barely conscious. Please fix it and try again.");
+@y
+  help2("One of your faux pas seems to have wounded me deeply...")@/
+    ("in fact, I'm barely conscious. Please fix it and try again.");
+@z
+
+305. Improved logic for `(see the transcript file...)' (Jan 23)
+@x module 245
+if history=spotless then history:=warning_issued;
+if (tracing_online<=0)and(selector=term_and_log) then decr(selector);
+@y
+if (tracing_online<=0)and(selector=term_and_log) then
+  begin decr(selector);
+  if history=spotless then history:=warning_issued;
+  end;
+@z
+
+306. Change 291 violated standard PASCAL (CET1, Feb 18)
+@x module 331
+for first:=0 to buf_size do buffer[first]:=0;
+@y since some procedures `threaten' |first| globally [BS/6192 sec 6.8.3.9]
+first:=buf_size; repeat buffer[first]:=0; decr(first); until first=0;
+@z
+
+307. Nonexistent character could be output via ligature hyphenation (April 11)
+@x module 582 (slight inefficiency removed while correcting this)
+begin if (font_bc[f]<=c)and(font_ec[f]>=c) then
+@y
+begin if font_bc[f]<=c then if font_ec[f]>=c then
+@z
+@x module 892 (likewise)
+@!hu:array[1..63] of ASCII_code; {like |hc|, before conversion to lowercase}
+@y
+@!hu:array[1..63] of ASCII_code; {like |hc|, before conversion to lowercase}
+@!hyf_char:integer; {hyphen character of the relevant font}
+@z
+@x module 896 (likewise)
+done2: if hyphen_char[hf]<0 then goto done1;
+if hyphen_char[hf]>255 then goto done1;
+@y
+done2: hyf_char:=hyphen_char[hf];
+if hyf_char<0 then goto done1;
+if hyf_char>255 then goto done1;
+@z
+@x module 912 and another local variable
+@!c:ASCII_code; {character temporarily replaced by a hyphen}
+@y
+@!c:ASCII_code; {character temporarily replaced by a hyphen}
+@!hyf_node:pointer; {the hyphen, if it exists}
+@z
+@x module 915 (this is the real bugfix)
+minor_tail:=null; c:=hu[i+1]; hu[i+1]:=hyphen_char[hf];
+repeat l:=reconstitute(l+1,i+1);
+if minor_tail=null then pre_break(r):=link(hold_head)
+else link(minor_tail):=link(hold_head);
+minor_tail:=link(hold_head);
+if link(minor_tail)<>null then minor_tail:=link(minor_tail);
+until l>i;
+hu[i+1]:=c; {restore the character in the hyphen position}
+decr(l); hyf[l]:=0
+@y
+minor_tail:=null; hyf_node:=new_character(hf,hyf_char);
+if hyf_node<>null then
+  begin incr(i); c:=hu[i]; hu[i]:=hyf_char;
+  end;
+repeat l:=reconstitute(l+1,i);
+if minor_tail=null then pre_break(r):=link(hold_head)
+else link(minor_tail):=link(hold_head);
+minor_tail:=link(hold_head);
+if link(minor_tail)<>null then minor_tail:=link(minor_tail);
+until l=i;
+if hyf_node<>null then
+  begin hu[i]:=c; {restore the character in the hyphen position}
+  free_avail(hyf_node); decr(i); l:=i;
+  end;
+hyf[i]:=0
+@z
+@x module 918
+begin r:=new_disc; pre_break(r):=new_character(hf,hyphen_char[hf]);
+@y
+begin r:=new_disc; pre_break(r):=new_character(hf,hyf_char);
+@z
+
+308. Improper memory usage computed by INITEX in change 300. (DRF, April 15)
+@x module 162
+@d hi_mem_stat_min==mem_top-13 {smallest statically allocated word in
+  the one-word |mem|}
+@y
+@d hi_mem_stat_min==mem_top-13 {smallest statically allocated word in
+  the one-word |mem|}
+@d hi_mem_stat_usage=14 {the number of one-word nodes always present}
+@z
+@x module 164 (text macro without parentheses strikes again!)
+var_used:=lo_mem_stat_max+1-mem_bot; dyn_used:=mem_top+1-hi_mem_stat_min;
+@y
+var_used:=lo_mem_stat_max+1-mem_bot; dyn_used:=hi_mem_stat_usage;
+@z
+
+309. A faster |flush_list| routine for the inner loop. (DRF, April 16)
+@x module 123
+var q:pointer; {the successor of node |p|}
+begin while p<>null do
+  begin q:=link(p); free_avail(p); p:=q;
+  end;
+@y
+var @!q,@!r:pointer; {list traversers}
+begin if p<>null then
+  begin r:=p;
+  repeat q:=r; r:=link(r); @!stat decr(dyn_used);@+tats@/
+  until r=null; {now |q| is the last node on the list}
+  link(q):=avail; avail:=p;
+  end;
+@z
+
+310. Kern for accent positioning could disappear after a line break (April 17)
+(Change 269 fixed only part of the problem!)
+@x module 155
+@d explicit=1 {|subtype| of kern nodes from \.{\\kern} and \.{\\/} and accents}
+@y
+@d explicit=1 {|subtype| of kern nodes from \.{\\kern} and \.{\\/}}
+@d acc_kern=2 {|subtype| of kern nodes from accents}
+@z
+@x module 191
+if subtype(p)<=explicit then
+  begin print_esc("kern");
+  if subtype(p)=explicit then print_char(" ");
+  print_scaled(width(p));
+@y
+if subtype(p)<>mu_glue then
+  begin print_esc("kern");
+  if subtype(p)<>normal then print_char(" ");
+  print_scaled(width(p));
+  if subtype(p)=acc_kern then print(" (for accent)");
+@.for accent@>
+@z
+@x module 837
+    math_node,kern_node: break_width[1]:=break_width[1]-width(s);
+@y
+    math_node,kern_node: if subtype(s)=acc_kern then goto done
+      else break_width[1]:=break_width[1]-width(s);
+@z
+@x module 879
+  if non_discardable(q) then goto done1;
+@y
+  if non_discardable(q) then goto done1;
+  if subtype(q)=acc_kern then if type(q)=kern_node then goto done1;
+@z
+@x module 1125
+r:=new_kern(delta); subtype(r):=explicit; link(tail):=r; link(r):=p;
+tail:=new_kern(-a-delta); subtype(tail):=explicit; link(p):=tail; p:=q;
+@y
+r:=new_kern(delta); subtype(r):=acc_kern; link(tail):=r; link(r):=p;
+tail:=new_kern(-a-delta); subtype(tail):=acc_kern; link(p):=tail; p:=q;
+@z
+
+311. \lastbox and \unkern must not remove discretionary replacements (April 18)
+(Change 236 introduced this bug!)
+@x module 1079
+label exit;
+var p:pointer; {runs through the current list}
+@y
+label exit, done;
+var @!p,@!q:pointer; {run through the current list}
+@!m:quarterword; {the length of a replacement list}
+@z
+@x modules 1080 and 1081
+  @<Apologize for inability to do \.{\\lastbox} now@>
+else  begin if not is_char_node(tail) then
+    if (type(tail)=hlist_node)or(type(tail)=vlist_node) then
+      begin p:=head; cur_box:=tail; shift_amount(cur_box):=0;
+      while link(p)<>tail do p:=link(p);
+      tail:=p; link(p):=null;
+      end;
+  end;
+end
+
+@ @<Apologize for inability to do \.{\\lastbox} now@>=
+begin you_cant;
+help2("Sorry...I'm usually unable to take things from the current")@/
+  ("page. This \lastbox will therefore be void."); error;
+end
+@y
+  begin you_cant;
+  help2("Sorry...I usually can't take things from the current page.")@/
+    ("This \lastbox will therefore be void."); error;
+  end
+else  begin if not is_char_node(tail) then
+    if (type(tail)=hlist_node)or(type(tail)=vlist_node) then
+      @<Remove the last box, unless it's part of a discretionary@>;
+  end;
+end
+
+@ @<Remove the last box...@>=
+begin q:=head;
+repeat p:=q;
+if not is_char_node(q) then if type(q)=disc_node then
+  begin for m:=1 to replace_count(q) do p:=link(p);
+  if p=tail then goto done;
+  end;
+q:=link(p);
+until q=tail;
+cur_box:=tail; shift_amount(cur_box):=0;
+tail:=p; link(p):=null;
+done: end
+@z
+@x module 1105
+var p:pointer; {runs through the current list}
+@y
+label exit;
+var @!p,@!q:pointer; {run through the current list}
+@!m:quarterword; {the length of a replacement list}
+@z
+@x module 1105
+    begin p:=head;
+    while link(p)<>tail do p:=link(p);
+    link(p):=null; flush_node_list(tail); tail:=p;
+    end;
+  end;
+end;
+@y
+    begin q:=head;
+    repeat p:=q;
+    if not is_char_node(q) then if type(q)=disc_node then
+      begin for m:=1 to replace_count(q) do p:=link(p);
+      if p=tail then return;
+      end;
+    q:=link(p);
+    until q=tail;
+    link(p):=null; flush_node_list(tail); tail:=p;
+    end;
+  end;
+exit:end;
+@z
+@x module 1106
+  help2("Sorry...I'm usually unable to take things from the current")@/
+    ("page. Try `I\vskip-\lastskip' instead.");
+  if cur_chr=kern_node then help_line[0]:=
+    ("page. Try `I\kern-\lastkern' instead.")
+  else if cur_chr<>glue_node then help_line[0]:=@|
+    ("page. Perhaps you can make the output routine do it.");
+@y
+  help2("Sorry...I usually can't take things from the current page.")@/
+    ("Try `I\vskip-\lastskip' instead.");
+  if cur_chr=kern_node then help_line[0]:=
+    ("Try `I\kern-\lastkern' instead.")
+  else if cur_chr<>glue_node then help_line[0]:=@|
+    ("Perhaps you can make the output routine do it.");
+@z
+@x module 1120
+if n<128 then replace_count(tail):=n
+@y
+if n<=max_quarterword then replace_count(tail):=n
+@z
+
+
+*** Note by DEK, 18 Apr 1985
+(The code for version 1.3 has been published by Addison-Wesley under the
+title "TeX: The Program". It was phototypeset on our APS, but does not
+contain changes > 300. Some of those changes have been made in versions
+of TeX called 1.3; but the exact definition of version 1.3 is somewhat
+vague. Version 1.4 was released on April 18, 1985, after
+making change 311. At present I believe Version 1.4 will be identical
+to Version 2.0 except perhaps for things like index entries in the
+documentation and slightly revised help messages. Version 2.0 will
+coincide with the publication of Volume 1 of Computers and Typesetting,
+which will come out when METAFONT and Computer Modern are both finished.)
+Version 1.5
+312. if nonstandard area specified, don't try TEX_area too. (DRF, 26 Apr 85)
+@x module 537
+  pack_file_name(cur_name,TEX_area,cur_ext);
+  if a_open_in(cur_file) then goto done;
+@y
+  if cur_area="" then
+    begin pack_file_name(cur_name,TEX_area,cur_ext);
+    if a_open_in(cur_file) then goto done;
+    end;
+@z
+
+313. length of \write need no longer be limited (cf 235). (NBT, 30 Apr 85)
+@x module 1370
+show_token_list(link(def_ref),null,buf_size-10); print_ln;
+@y
+show_token_list(link(def_ref),null,10000000); print_ln;
+@z
+
+314. bug introduced in #300, just lucky it didn't cause trouble (CET1, 8 May 85)
+@x module 162
+@d active==mem_top-6 {head of active list in |line_break|, needs two words}
+@y
+@d active==mem_top-7 {head of active list in |line_break|, needs two words}
+@z
+
+315. Missing eoln after last typeout (Gropp, 11 May 85)
+@x module 1332
+  wterm('Ouch---my internal constants have been',
+@y
+  wterm_ln('Ouch---my internal constants have been',
+@z
+
+316. Redundancy (CET1, 17 May 85)
+[Change 287 was apparently introduced because of a faulty assumption,
+although its change to the calling of "initialize" was valid.]
+@x module 1332
+  begin t_open_out;
+  wterm_ln('Ouch---my internal constants have been',
+    ' clobbered!---case ',bad:1);
+@y
+  begin wterm_ln('Ouch---my internal constants have been clobbered!',
+    '---case ',bad:1);
+@z
+
+317. batchmode to see if log file couldn't be opened (DRF, 22 May 85)
+@x module 92
+if interaction=batch_mode then decr(selector);
+if job_name=0 then open_log_file;
+@y
+if job_name=0 then open_log_file;
+if interaction=batch_mode then decr(selector);
+@z
+
+318. If the string pool overflows while reading the command line... (22 May 85)
+[This bug was first found in METAFONT, when it could occur more easily]
+@x module 525
+begin str_room(name_length);
+for k:=1 to name_length do append_char(xord[name_of_file[k]]);
+make_name_string:=make_string;
+@y
+begin if (pool_ptr+name_length>pool_size)or(str_ptr=max_strings) then
+  make_name_string:="?"
+else  begin for k:=1 to name_length do append_char(xord[name_of_file[k]]);
+  make_name_string:=make_string;
+  end;
+@z
+
+319. Bug in \edef\foo{\iffalse\fi\the\toks0} (found by Dan Brotsky, 7 Aug 85)
+@x module 478
+  if cur_cmd<>the then goto done2;
+  q:=the_toks;
+  if link(temp_head)<>null then
+    begin link(p):=link(temp_head); p:=q;
+    end;
+@y
+  if cur_cmd<=max_command then goto done2;
+  if cur_cmd<>the then expand
+  else  begin q:=the_toks;
+    if link(temp_head)<>null then
+      begin link(p):=link(temp_head); p:=q;
+      end;
+    end;
+@z
+
+*** Version 1.5 was released on August 7, 1985.
+
+320. Lowercase `plain' for consistency with the manual
+@x module 521
+TEX_format_default:='TeXformats:PLAIN.fmt';
+@.TeXformats@>
+@.PLAIN@>
+@y
+TEX_format_default:='TeXformats:plain.fmt';
+@.TeXformats@>
+@.plain@>
+@z (index entries also changed to lowercase in modules 524, 1331)
+
+321. Terminal woken up by \show and \showthe (November 27, 1985)
+@x module 1294
+begin get_token; print_nl("> ");
+@y
+begin get_token;
+if interaction=error_stop_mode then wake_up_terminal;
+print_nl("> ");
+@z
+@x module 1297
+begin p:=the_toks; print_nl("> "); token_show(temp_head);
+@y
+begin p:=the_toks;
+if interaction=error_stop_mode then wake_up_terminal;
+print_nl("> "); token_show(temp_head);
+@z
+Changes subsequent to `Version 2.0' as published in C&T, Volume B:
+
+322. Trivial change to a help message.
+@x module 1283
+  ("Pretend that you're Hercule Poirot, examine all clues,")@/
+@y
+  ("Pretend that you're Hercule Poirot: Examine all clues,")@/
+@z
+
+323. Precaution since |index| can be as high as |max_in_open|. (DRF)
+@x module 14
+if hash_prime>hash_size then bad:=5;
+@y
+if hash_prime>hash_size then bad:=5;
+if max_in_open>=128 then bad:=6;
+@z
+
+324. \kern clobbered at end of pre-break list in discretionary break.
+@x module 881
+        |disc_break:=true|@>;
+    if not is_char_node(q) then
+      if (type(q)=math_node)or(type(q)=kern_node) then width(q):=0;
+@y
+        |disc_break:=true|@>
+    else if (type(q)=math_node)or(type(q)=kern_node) then width(q):=0;
+@z
+
+325. width after discretionary didn't take account of discarded nodes.
+@x module 830 (slight redefinition)
+@!t:quarterword; {replacement count, if |cur_p| is a discretionary node}
+@y
+@!t:integer; {node count, if |cur_p| is a discretionary node}
+@z
+@x module 837 (slight rearrangement)
+if (break_type=unhyphenated)or(cur_p=null) then
+  begin s:=cur_p;
+  while s<>null do
+    begin if is_char_node(s) then goto done;
+    case type(s) of
+    glue_node:@<Subtract glue from |break_width|@>;
+    penalty_node: do_nothing;
+    math_node,kern_node: if subtype(s)=acc_kern then goto done
+      else break_width[1]:=break_width[1]-width(s);
+    othercases goto done
+    endcases;@/
+    s:=link(s);
+    end;
+  end
+else @<Compute the discretionary |break_width| values@>;
+@y
+s:=cur_p;
+if break_type>unhyphenated then if cur_p<>null then
+  @<Compute the discretionary |break_width| values@>;
+while s<>null do
+  begin if is_char_node(s) then goto done;
+  case type(s) of
+  glue_node:@<Subtract glue from |break_width|@>;
+  penalty_node: do_nothing;
+  math_node,kern_node: if subtype(s)=acc_kern then goto done
+    else break_width[1]:=break_width[1]-width(s);
+  othercases goto done
+  endcases;@/
+  s:=link(s);
+  end;
+@z
+@x module 840 (this is the main change to fix the bug)
+begin t:=replace_count(cur_p); s:=cur_p;
+while t>0 do
+  begin decr(t); s:=link(s);
+  @<Subtract the width of node |s| from |break_width|@>;
+  end;
+s:=post_break(cur_p);
+while s<>null do
+  begin @<Add the width of node |s| to |break_width|@>;
+@y
+begin t:=replace_count(cur_p); v:=cur_p; s:=post_break(cur_p);
+while t>0 do
+  begin decr(t); v:=link(v);
+  @<Subtract the width of node |v| from |break_width|@>;
+  end;
+while s<>null do
+  begin @<Add the width of node |s| to |break_width| and increase |t|,
+    unless it's discardable@>;
+@z
+@x module 840, continued
+break_width[1]:=break_width[1]+disc_width;
+@y
+break_width[1]:=break_width[1]+disc_width;
+if t=0 then s:=link(v); {more nodes may also be discardable after the break}
+@z
+@x module 841 (here we just change |s| to |v|)
+@<Subtract the width of node |s|...@>=
+if is_char_node(s) then
+  begin f:=font(s);
+  break_width[1]:=break_width[1]-char_width(f)(char_info(f)(character(s)));
+  end
+else  case type(s) of
+  ligature_node: begin f:=font(lig_char(s));@/
+    break_width[1]:=@|break_width[1]-
+      char_width(f)(char_info(f)(character(lig_char(s))));
+    end;
+  hlist_node,vlist_node,rule_node,kern_node:
+    break_width[1]:=break_width[1]-width(s);
+@y
+@<Subtract the width of node |v|...@>=
+if is_char_node(v) then
+  begin f:=font(v);
+  break_width[1]:=break_width[1]-char_width(f)(char_info(f)(character(v)));
+  end
+else  case type(v) of
+  ligature_node: begin f:=font(lig_char(v));@/
+    break_width[1]:=@|break_width[1]-
+      char_width(f)(char_info(f)(character(lig_char(v))));
+    end;
+  hlist_node,vlist_node,rule_node,kern_node:
+    break_width[1]:=break_width[1]-width(v);
+@z
+@x module 842
+  hlist_node,vlist_node,rule_node,kern_node:
+    break_width[1]:=break_width[1]+width(s);
+  othercases confusion("disc2")
+@:this can't happen disc2}{\quad disc2@>
+  endcases
+@y
+  hlist_node,vlist_node,rule_node:break_width[1]:=break_width[1]+width(s);
+  kern_node: if (t=0)and(subtype(s)<>acc_kern) then t:=-1 {discardable}
+    else break_width[1]:=break_width[1]+width(s);
+  othercases confusion("disc2")
+@:this can't happen disc2}{\quad disc2@>
+  endcases;
+incr(t)
+@z
+
+*** Version 2.1 was released on January 26, 1987.
+
+326. Removal of redundant code (found by Pat Monardo, 5 Feb 87)
+@x module 1224 [this change need not be made, since it has no effect]
+    char_def_code: define(p,char_given,cur_val);
+    math_char_def_code: define(p,math_given,cur_val);
+@y the cases cannot occur, so we simply don't list them
+@z
+
+327. More robustness is needed when debugging (Ronaldo Am\'a, 14 Apr 87)
+@x module 174
+begin while p>null do
+@y maybe mem_min>null (but nodes shouldn't be put in location mem_min exactly)
+begin while p>mem_min do
+@z
+@x module 182
+@p procedure show_node_list(@!p:pointer); {prints a node list symbolically}
+@y
+@p procedure show_node_list(@!p:integer); {prints a node list symbolically}
+@z
+@x module 182, continued
+while p>null do
+@y
+while p>mem_min do
+@z
+
+328. Storage allocation can be more elegant and efficient (4/21/87)
+@x module 127
+if r=p then if ((rlink(p)<>rover) or (llink(p)<>rover)) then
+@y
+if r=p then if rlink(p)<>p then
+@z
+
+329. Miscalculation of empty-line condition (April 22, 1987)
+@x module 360
+    begin if limit=start then {previous line was empty}
+@y
+    begin if (end_line_char<0)or(end_line_char>127) then incr(limit);
+    if limit=start then {previous line was empty}
+@z
+
+330. A case where we don't have to assume system bookkeeping (April 28, 1987)
+@x module 560
+done: b_close(tfm_file); read_font_info:=g;
+@y [suggested by Jim Sterken]
+done: if file_opened then b_close(tfm_file);
+read_font_info:=g;
+@z [this was not a bug, according to the comment in module 28]
+
+331. jump_out must fix unfinished output (Found by Klaus Gunterman, 3 Aug 87)
+@x module 593
+doing_leaders:=false; dead_cycles:=0;
+@y
+doing_leaders:=false; dead_cycles:=0; cur_s:=-1;
+@z
+@x module 617
+cur_s:=-1; ensure_dvi_open;
+@y
+ensure_dvi_open;
+@z
+@x module 640
+dvi_out(eop); incr(total_pages);
+@y
+dvi_out(eop); incr(total_pages); cur_s:=-1;
+@z
+@x module 642
+if total_pages=0 then print_nl("No pages of output.")
+@y
+while cur_s>-1 do
+  begin if cur_s>0 then dvi_out(pop)
+  else  begin dvi_out(eop); incr(total_pages);
+    end;
+  decr(cur_s);
+  end;
+if total_pages=0 then print_nl("No pages of output.")
+@z
+
+332. \hangindent=1pt$$\halign{...\cr\noalign{\hrule}}$$ problem (19 Aug 87)
+@x module 805
+q:=link(head);
+@y
+q:=link(head); s:=head;
+@z
+@x module 805, continued
+  q:=link(q);
+@y
+  s:=q; q:=link(q);
+@z
+@x module 806
+if is_running(depth(q)) then depth(q):=depth(p);
+@y
+if is_running(depth(q)) then depth(q):=depth(p);
+if o<>0 then
+  begin r:=link(q); link(q):=null; q:=hpack(q,natural);
+  shift_amount(q):=o; link(q):=r; link(s):=q;
+  end;
+@z
+
+333. \hskip 0pt plus 1fil\ifdim problem (found by Alan Guth, 20 Aug 87)
+@x module 366
+@!cvl_backup,@!radix_backup:small_number; {to save |cur_val_level| and |radix|}
+@y
+@!cvl_backup,@!radix_backup,@!co_backup:small_number;
+  {to save |cur_val_level|, etc.}
+@z
+@x
+backup_backup:=link(backup_head);
+@y
+co_backup:=cur_order; backup_backup:=link(backup_head);
+@z
+@x
+link(backup_head):=backup_backup;
+@y
+cur_order:=co_backup; link(backup_head):=backup_backup;
+@z
+
+334. leaders too sensitive near exact multiples (M. F. Bridgland, 9 Nov 87)
+@x module 626
+  begin edge:=cur_h+rule_wd; lx:=0;
+@y
+  begin rule_wd:=rule_wd+10; {compensate for floating-point rounding}
+  edge:=cur_h+rule_wd; lx:=0;
+@z
+@x ibid
+  cur_h:=edge; goto next_p;
+@y
+  cur_h:=edge-10; goto next_p;
+@z
+@x module 635
+  begin edge:=cur_v+rule_ht; lx:=0;
+@y
+  begin rule_ht:=rule_ht+10; {compensate for floating-point rounding}
+  edge:=cur_v+rule_ht; lx:=0;
+@z
+@x ibid
+  cur_v:=edge; goto next_p;
+@y
+  cur_v:=edge-10; goto next_p;
+@z
+
+335. Glitch in fixed-point multiplication of negatives (W.G. Sullivan, 17Nov87)
+@x module 572
+begin alpha:=16*z; beta:=16;
+while z>=@'40000000 do
+  begin z:=z div 2; beta:=beta div 2;
+  end;
+@y
+begin alpha:=16;
+while z>=@'40000000 do
+  begin z:=z div 2; alpha:=alpha+alpha;
+  end;
+beta:=256 div alpha; alpha:=alpha*z;
+@z
+
+336. If there are no \patterns and some \lccode is 1 (Breitenlohner, 12Dec87)
+@x module 952
+trie_link(0):=0; trie_char(0):=0; trie_op(0):=0;
+@y
+trie_link(0):=0; trie_char(0):=0; trie_op(0):=min_quarterword;
+@z
+
+337. \csname might encounter undefined_cs in a group (Chris Thompson, 23Dec87)
+@x module 372
+  begin eqtb[cur_cs]:=eqtb[frozen_relax];
+@y
+  begin eq_define(cur_cs,relax,256);
+@z
+
+338. \outer\def\a0{}\a\a shows temp_head list garbage (Silvio Levy, 20Apr88)
+@x module 391
+repeat if (info(r)>match_token+127)or(info(r)<match_token) then s:=null
+else  begin match_chr:=info(r)-match_token; s:=link(r); r:=s;
+  p:=temp_head; link(p):=null; m:=0;
+@y
+repeat link(temp_head):=null;
+if (info(r)>match_token+127)or(info(r)<match_token) then s:=null
+else  begin match_chr:=info(r)-match_token; s:=link(r); r:=s;
+  p:=temp_head; m:=0;
+@z
+
+339. \def\\#1{}\input a\\\z failed (Robert Messer, 24Apr88)
+@x module 259
+var h:integer; {hash code}
+@y
+var h:integer; {hash code}
+@!d:integer; {number of characters in incomplete current string}
+@z
+@x module 260
+str_room(l);
+for k:=j to j+l-1 do append_char(buffer[k]);
+text(p):=make_string;
+@y
+str_room(l); d:=cur_length;
+while pool_ptr>str_start[str_ptr] do
+  begin decr(pool_ptr); str_pool[pool_ptr+l]:=str_pool[pool_ptr];
+  end; {move current string up to make room for another}
+for k:=j to j+l-1 do append_char(buffer[k]);
+text(p):=make_string; pool_ptr:=pool_ptr+d;
+@z
+
+340. Make patterns work when trie_min=0 (Peter Breitenlohner, 10May88)
+@x module 951
+trie_max:=128; trie_min:=128; trie_link(0):=1; trie_taken[0]:=false;
+@y
+trie_max:=128; trie_min:=128; trie_link(0):=1; trie_taken[0]:=false;
+trie_link(trie_size):=0; trie_back(0):=trie_size; {wrap around}
+@z
+@x module 953
+begin c:=trie_c[p]; {we have |c>0|}
+if c<trie_min then trie_min:=c;
+z:=trie_link(trie_min-1); {get the first conceivably good hole}
+@y
+begin c:=trie_c[p];
+if c<trie_min then trie_min:=c;
+if trie_min=0 then z:=trie_link(trie_size)
+else z:=trie_link(trie_min-1); {get the first conceivably good hole}
+@z
+@x module 966
+r:=0; {finally, we will zero out the holes}
+@y
+r:=trie_size; {finally, we will zero out the holes}
+@z
+
+341. Avoid possible trie_pointer out of range (24May88)
+@x module 923
+hc[0]:=127; hc[hn+1]:=127; hc[hn+2]:=256; {insert delimiters}
+@y
+hc[0]:=127; hc[hn+1]:=127; hc[hn+2]:=128; {insert delimiters}
+@z
+
+342. \input a\romannumeral1 etc.; similar to bug 339. (25May88)
+@x module 464
+@p function str_toks:pointer; {changes the current string to a token list}
+@y
+@p function str_toks(@!b:pool_pointer):pointer;
+  {changes the string |str_pool[b..pool_ptr]| to a token list}
+@z
+@x module 464, continued
+p:=temp_head; link(p):=null; k:=str_start[str_ptr];
+@y
+p:=temp_head; link(p):=null; k:=b;
+@z
+@x module 464, concluded
+pool_ptr:=str_start[str_ptr]; str_toks:=p;
+@y
+pool_ptr:=b; str_toks:=p;
+@z
+@x module 465
+begin get_x_token; scan_something_internal(tok_val,false);
+if cur_val_level>=ident_val then @<Copy the token list@>
+else begin old_setting:=selector; selector:=new_string;
+@y
+@!b:pool_pointer; {base of temporary string}
+begin get_x_token; scan_something_internal(tok_val,false);
+if cur_val_level>=ident_val then @<Copy the token list@>
+else begin old_setting:=selector; selector:=new_string; b:=pool_ptr;
+@z
+@x module 465, continued
+  selector:=old_setting; the_toks:=str_toks;
+@y
+  selector:=old_setting; the_toks:=str_toks(b);
+@z
+@x module 470
+begin c:=cur_chr; @<Scan the argument for command |c|@>;
+old_setting:=selector; selector:=new_string;
+@<Print the result of command |c|@>;
+selector:=old_setting; link(garbage):=str_toks; ins_list(link(temp_head));
+@y
+@!b:pool_pointer; {base of temporary string}
+begin c:=cur_chr; @<Scan the argument for command |c|@>;
+old_setting:=selector; selector:=new_string; b:=pool_ptr;
+@<Print the result of command |c|@>;
+selector:=old_setting; link(garbage):=str_toks(b); ins_list(link(temp_head));
+@z
+
+343. **\input\romannumeral6 confusion bypassed (25May88)
+@x module 525
+begin if (pool_ptr+name_length>pool_size)or(str_ptr=max_strings) then
+@y
+begin if (pool_ptr+name_length>pool_size)or(str_ptr=max_strings)or
+ (cur_length>0) then
+@z
+
+344. Avoid negative dividend rounding upward (Chris Thompson, fixed 19Jun88)
+@x module 126
+else t:=(lo_mem_max+hi_mem_min+2) div 2; {|lo_mem_max+2<=t<hi_mem_min|}
+@y
+else t:=lo_mem_max+1+(hi_mem_min-lo_mem_max)div 2; {|lo_mem_max+2<=t<hi_mem_min|}
+@z
+
+345. Better strategy when near memory overflow (Chris Thompson)
+@x module 126
+begin if lo_mem_max+1000<hi_mem_min then t:=lo_mem_max+1000
+@y
+begin if hi_mem_min-lo_mem_max>=1998 then t:=lo_mem_max+1000
+@z
+
+346. An omission from change 333 (Tsunetoshi Hayashi, reported 20June88)
+@x module 439
+cur_val:=0; cur_val_level:=int_val; radix:=0;
+@y
+cur_val:=0; cur_val_level:=int_val; radix:=0; cur_order:=0;
+@z
+
+347. Avoid fatal_error after terminal eof (Tim Morgan, reported 25Oct88)
+@x module 71 [serious problem occurred if this was called in open_log_file]
+if not input_ln(term_in,true) then fatal_error("End of file on the terminal!");
+@y
+if not input_ln(term_in,true) then t_open_in;
+@z
+
+348. Force terminal output when open_log_file aborts (6Nov88)
+@x module 535
+  begin print_err("I can't write on file `");
+@y
+  begin selector:=term_only; print_err("I can't write on file `");
+@z
+
+349. By popular request, undo #347 and fix the bug a more complex way.
+@x module 71 [this undoes change #347]
+if not input_ln(term_in,true) then t_open_in;
+@y
+if not input_ln(term_in,true) then fatal_error("End of file on the terminal!");
+@z
+@x module 92 [now we get to the new stuff]
+begin if job_name>0 then selector:=term_and_log
+@y
+begin if log_opened then selector:=term_and_log
+@z
+@x module 93
+  error;
+@y
+  if log_opened then error;
+@z
+@x module 527
+@!job_name:str_number; {principal file name}
+@y
+@!job_name:str_number; {principal file name}
+@!log_opened:boolean; {has the transcript file been opened?}
+@z
+@x module 528
+@<Initialize the output...@>=job_name:=0; name_in_progress:=false;
+@y
+@<Initialize the output...@>=
+job_name:=0; name_in_progress:=false; log_opened:=false;
+@z
+@x module 534
+selector:=log_only;
+@y
+selector:=log_only; log_opened:=true;
+@z
+@x module 535
+begin if interaction<scroll_mode then {bypass |fatal_error|}
+  begin selector:=term_only; print_err("I can't write on file `");
+@.I can't write on file x@>
+  print_file_name(cur_name,cur_area,cur_ext); print("'.");@/
+  job_name:=0; history:=fatal_error_stop; jump_out;
+  end; {abort the program without a log file}
+@y
+begin selector:=term_only;
+@z
+@x module 1265 [this change is optional, but it's a slight improvement]
+if job_name<>0 then selector:=selector+2;
+@y
+if log_opened then selector:=selector+2;
+@z
+@x module 1333
+if job_name>0 then
+@y
+if log_opened then
+@z
+@x module 1334
+if job_name>0 then {the log file is open}
+@y
+if log_opened then
+@z
+
+350. Forgotten update in error recovery (Breitenlohner, 20 Jan 89)
+@x module 976
+    glue_ptr(p):=r;
+@y
+    glue_ptr(p):=r; q:=r;
+@z
+@x module 1004
+    glue_ptr(p):=r;
+@y
+    glue_ptr(p):=r; q:=r;
+@z
+
+351. Avoid error \aftergroup\relax\dump (Mittelbach&Schoepf, 17 Feb 89)
+@x module 280
+begin check_full_save_stack;
+save_type(save_ptr):=insert_token; save_level(save_ptr):=level_zero;
+save_index(save_ptr):=t; incr(save_ptr);
+@y
+begin if cur_level>level_one then
+  begin check_full_save_stack;
+  save_type(save_ptr):=insert_token; save_level(save_ptr):=level_zero;
+  save_index(save_ptr):=t; incr(save_ptr);
+  end;
+@z
+
+352. Cosmetic change to validate comment in 115 (Breitenlohner, 20 Mar 89)
+@x module 791
+begin q:=link(cur_align);
+if (cur_align=null)or(q=null) then confusion("endv");
+@y
+begin if cur_align=null then confusion("endv");
+q:=link(cur_align);@+if q=null then confusion("endv");
+@z
+
+353. $$\begingroup\halign{#\cr}$$ caused confusion (Mittelbach, 7 Jun 89)
+@x module 1130
+mmode+halign: if privileged then init_align;
+@y
+mmode+halign: if privileged then
+  if cur_group=math_shift_group then init_align
+  else off_save;
+@z
+
+354. Conflict in global array dig with .5\ifdim.6 (Mittelbach, 20 Jun 89)
+@x module 450
+@!k:small_number; {number of digits in a decimal fraction}
+@y
+@!k,@!kk:small_number; {number of digits in a decimal fraction}
+@!p,@!q:pointer; {top of decimal digit stack}
+@z
+@x module 452
+begin k:=0; get_token; {|point_token| is being re-scanned}
+loop@+  begin get_x_token;
+  if (cur_tok>zero_token+9)or(cur_tok<zero_token) then goto done1;
+  if k<17 then {digits for |k>=17| cannot affect the result}
+    begin dig[k]:=cur_tok-zero_token; incr(k);
+    end;
+  end;
+done1: f:=round_decimals(k);
+@y
+begin k:=0; p:=null; get_token; {|point_token| is being re-scanned}
+loop@+  begin get_x_token;
+  if (cur_tok>zero_token+9)or(cur_tok<zero_token) then goto done1;
+  if k<17 then {digits for |k>=17| cannot affect the result}
+    begin q:=get_avail; link(q):=p; info(q):=cur_tok-zero_token;
+    p:=q; incr(k);
+    end;
+  end;
+done1: for kk:=k downto 1 do
+  begin dig[kk-1]:=info(p); q:=p; p:=link(p); free_avail(q);
+  end;
+f:=round_decimals(k);
+@z
+
+355. String startup problems (Wayne Sullivan, 17 Jul 89)
+@x module 31 (Warning: This affects most change files!)
+        overflow("buffer size",buf_size);
+@:TeX capacity exceeded buffer size}{\quad buffer size@>
+@y
+        @<Report overflow of the input buffer, and abort@>;
+@z
+@x module 35
+consist of the remainder of the command line, after the part that invoked
+\TeX.
+@y
+consist of the remainder of the command line, after the part that invoked
+\TeX.
+
+The first line is special also because it may be read before \TeX\ has
+input a format file. In such cases, normal error messages cannot yet
+be given. The following code uses concepts that will be explained later.
+
+@<Report overflow of the input buffer, and abort@>=
+if format_ident=0 then
+  begin write_ln(term_out,'Buffer size exceeded!'); goto final_end;
+@.Buffer size exceeded@>
+  end
+else begin cur_input.loc_field:=first; cur_input.limit_field:=last-1;
+  overflow("buffer size",buf_size);
+@:TeX capacity exceeded buffer size}{\quad buffer size@>
+  end
+@z
+@x module 1310
+k:=pool_ptr-4; undump_four_ASCII
+@y
+k:=pool_ptr-4; undump_four_ASCII;
+init_str_ptr:=str_ptr; init_pool_ptr:=pool_ptr
+@z
+@x module 1332
+tini@/
+@y
+init_str_ptr:=str_ptr; init_pool_ptr:=pool_ptr; fix_date_and_time;
+tini@/
+@z
+@x module 1332
+init_str_ptr:=str_ptr; init_pool_ptr:=pool_ptr;@/
+@y
+@z
+
+356. Allow integer products to be 31 bits long (Mittelbach, 16 Aug 89)
+@x module 105
+@p function nx_plus_y(@!n:integer;@!x,@!y:scaled):scaled;
+begin if n<0 then
+  begin negate(x); negate(n);
+  end;
+if n=0 then nx_plus_y:=y
+else if ((x<=(@'7777777777-y) div n)and(-x<=(@'7777777777+y) div n)) then
+  nx_plus_y:=n*x+y
+else  begin arith_error:=true; nx_plus_y:=0;
+  end;
+end;
+@y
+@d nx_plus_y(#)==mult_and_add(#,@'7777777777)
+@d mult_integers(#)==mult_and_add(#,0,@'17777777777)
+
+@p function mult_and_add(@!n:integer;@!x,@!y,@!max_answer:scaled):scaled;
+begin if n<0 then
+  begin negate(x); negate(n);
+  end;
+if n=0 then mult_and_add:=y
+else if ((x<=(max_answer-y) div n)and(-x<=(max_answer+y) div n)) then
+  mult_and_add:=n*x+y
+else  begin arith_error:=true; mult_and_add:=0;
+  end;
+end;
+@z
+@x module 1240
+  if q=multiply then cur_val:=nx_plus_y(eqtb[l].int,cur_val,0)
+@y
+  if q=multiply then
+    if p=int_val then cur_val:=mult_integers(eqtb[l].int,cur_val)
+    else cur_val:=nx_plus_y(eqtb[l].int,cur_val,0)
+@z
+
+357. Raise the maximum number of tokens normally shown (pointed out by
+John Lavagnino in TeXhax on 19 May 89; corrected on 31 Aug 89).
+@x module 295
+begin if p<>null then show_token_list(link(p),null,1000);
+@y
+begin if p<>null then show_token_list(link(p),null,10000000);
+@z
+@x module 1370 (this part of the change is cosmetic only)
+show_token_list(link(def_ref),null,10000000); print_ln;
+@y
+token_show(def_ref); print_ln;
+@z
+
+358. Like 353, but with $$\begingroup\eqno$$ (Mittelbach, 25 Jul 89)
+@x module 1140
+mmode+eq_no: if privileged then start_eq_no;
+@y
+mmode+eq_no: if privileged then
+  if cur_group=math_shift_group then start_eq_no
+  else off_save;
+@z
+
+359. Major extension to 8-bit character input. (These changes, and a few that
+follow, were discussed during the 10th TUG meeting and installed during
+the week of 10 Sep 1989. They bring the implementation of TeX82 up to date with
+international developments and experience, and I believe they mark the
+final development of this program into a completely stable system.)
+Several changes to the documentation (not the program) are omitted here.
+@x module 18
+@!ASCII_code=0..127; {seven-bit numbers}
+@y
+@!ASCII_code=0..255; {eight-bit numbers}
+@z
+@x module 19
+@d last_text_char=127 {ordinal number of the largest element of |text_char|}
+
+@<Local variables for init...@>=
+@!i:0..last_text_char;
+@y
+@d last_text_char=255 {ordinal number of the largest element of |text_char|}
+
+@<Local variables for init...@>=
+@!i:integer;
+@z
+@x module 21
+xchr[0]:=' '; xchr[@'177]:=' ';
+  {ASCII codes 0 and |@'177| do not appear in text}
+@y
+@z
+@x module 23
+for i:=1 to @'37 do xchr[i]:=' ';
+@y changing ' ' to chr(i) here will allow all 8-bit characters to get in
+for i:=0 to @'37 do xchr[i]:=' ';
+for i:=@'177 to @'377 do xchr[i]:=' ';
+@z
+@x module 24
+for i:=1 to @'176 do xord[xchr[i]]:=i;
+@y
+for i:=@'200 to @'377 do xord[xchr[i]]:=i;
+for i:=0 to @'176 do xord[xchr[i]]:=i;
+@z
+@x module 38
+@<Types...@>=
+@!pool_pointer = 0..pool_size; {for variables that point into |str_pool|}
+@!str_number = 0..max_strings; {for variables that point into |str_start|}
+
+@ @<Glob...@>=
+@!str_pool:packed array[pool_pointer] of ASCII_code; {the characters}
+@y [OK to make si(#)==#-128 and so(#)==#+128 (without parens) in change files]
+Some \PASCAL\ compilers won't pack integers into a single byte unless the
+integers lie in the range |-128..127|. To accommodate such systems
+we access the string pool only via macros that can easily be redefined.
+
+@d si(#) == # {convert from |ASCII_code| to |packed_ASCII_code|}
+@d so(#) == # {convert from |packed_ASCII_code| to |ASCII_code|}
+
+@<Types...@>=
+@!pool_pointer = 0..pool_size; {for variables that point into |str_pool|}
+@!str_number = 0..max_strings; {for variables that point into |str_start|}
+@!packed_ASCII_code = 0..255; {elements of |str_pool| array}
+
+@ @<Glob...@>=
+@!str_pool:packed array[pool_pointer] of packed_ASCII_code; {the characters}
+@z
+@x module 42
+begin str_pool[pool_ptr]:=#; incr(pool_ptr);
+@y
+begin str_pool[pool_ptr]:=si(#); incr(pool_ptr);
+@z
+@x module 45
+  begin if str_pool[j]<>buffer[k] then
+@y
+  begin if so(str_pool[j])<>buffer[k] then
+@z
+@x module 47
+var k,@!l:0..127; {small indices or counters}
+@y
+var k,@!l:0..255; {small indices or counters}
+@z
+@x module 47
+@<Make the first 128 strings@>;
+@y
+@<Make the first 256 strings@>;
+@z
+@x module 48
+@ @<Make the first 128...@>=
+for k:=0 to 127 do
+  begin if (@<Character |k| cannot be printed@>) then
+    begin append_char("^"); append_char("^");
+    if k<@'100 then append_char(k+@'100)
+    else append_char(k-@'100);
+@y
+@ @d app_lc_hex(#)==l:=#;
+  if l<10 then append_char(l+"0)@+else append_char(l-10+"a")
+
+@<Make the first 256...@>=
+for k:=0 to 255 do
+  begin if (@<Character |k| cannot be printed@>) then
+    begin append_char("^"); append_char("^");
+    if k<@'100 then append_char(k+@'100)
+    else if k<@'200 then append_char(k-@'100)
+    else begin app_lc_hex(k div 16); app_lc_hex(k mod 16);
+      end;
+@z
+@x module 59
+  begin print_char(str_pool[j]); incr(j);
+@y
+  begin print_char(so(str_pool[j])); incr(j);
+@z
+@x modules 59 and 60
+else if s<128 then
+@y
+else if s<256 then
+@z
+@x module 60
+  begin print(str_pool[j]); incr(j);
+@y
+  begin print(so(str_pool[j])); incr(j);
+@z
+@x module 63
+if c>=0 then if c<128 then print(c);
+@y
+if c>=0 then if c<256 then print(c);
+@z
+@x module 68
+@ In certain situations, \TeX\ prints either a standard visible ASCII
+character or its hexadecimal ASCII code.
+
+@p procedure print_ASCII(@!c:integer); {prints a character or its code}
+begin if (c>=0) and (c<=127) then print(c)
+else  begin print_char("[");
+  if c<0 then print_int(c)@+else print_hex(c);
+  print_char("]");
+  end;
+end;
+@y
+@ Old versions of \TeX\ needed a procedure called |print_ASCII| whose function
+is now subsumed by |print|. We retain the old name here as a possible aid to
+future software arch\ae ologists.
+
+@d print_ASCII == print
+@z
+@x module 69
+    begin print_char(str_pool[j]); n:=n-v;
+    end;
+  if n<=0 then return; {nonpositive input produces no output}
+  k:=j+2; u:=v div (str_pool[k-1]-"0");
+  if str_pool[k-1]="2" then
+    begin k:=k+2; u:=u div (str_pool[k-1]-"0");
+    end;
+  if n+u>=v then
+    begin print_char(str_pool[k]); n:=n+u;
+    end
+  else  begin j:=j+2; v:=v div (str_pool[j-1]-"0");
+@y
+    begin print_char(so(str_pool[j])); n:=n-v;
+    end;
+  if n<=0 then return; {nonpositive input produces no output}
+  k:=j+2; u:=v div (so(str_pool[k-1])-"0");
+  if str_pool[k-1]=si("2") then
+    begin k:=k+2; u:=u div (so(str_pool[k-1])-"0");
+    end;
+  if n+u>=v then
+    begin print_char(so(str_pool[k])); n:=n+u;
+    end
+  else  begin j:=j+2; v:=v div (so(str_pool[j-1])-"0");
+@z
+@x module 70
+  begin print_char(str_pool[j]); incr(j);
+@y
+  begin print_char(so(str_pool[j])); incr(j);
+@z
+@x module 222
+@d single_base=active_base+128 {equivalents of one-letter control sequences}
+@d null_cs=single_base+128 {equivalent of \.{\\csname\\endcsname}}
+@y
+@d single_base=active_base+256 {equivalents of one-character control sequences}
+@d null_cs=single_base+256 {equivalent of \.{\\csname\\endcsname}}
+@z
+@x module 230
+  {table of 128 command codes (the ``catcodes'')}
+@d lc_code_base=cat_code_base+128 {table of 128 lowercase mappings}
+@d uc_code_base=lc_code_base+128 {table of 128 uppercase mappings}
+@d sf_code_base=uc_code_base+128 {table of 128 spacefactor mappings}
+@d math_code_base=sf_code_base+128 {table of 128 math mode mappings}
+@d int_base=math_code_base+128 {beginning of region 5}
+@y
+  {table of 256 command codes (the ``catcodes'')}
+@d lc_code_base=cat_code_base+256 {table of 256 lowercase mappings}
+@d uc_code_base=lc_code_base+256 {table of 256 uppercase mappings}
+@d sf_code_base=uc_code_base+256 {table of 256 spacefactor mappings}
+@d math_code_base=sf_code_base+256 {table of 256 math mode mappings}
+@d int_base=math_code_base+256 {beginning of region 5}
+@z
+@x module 232
+for k:=0 to 127 do
+@y
+for k:=0 to 255 do
+@z
+@x module 236
+@d del_code_base=count_base+256 {128 delimiter code mappings}
+@d dimen_base=del_code_base+128 {beginning of region 6}
+@y
+@d del_code_base=count_base+256 {256 delimiter code mappings}
+@d dimen_base=del_code_base+256 {beginning of region 6}
+@z
+@x module 240
+for k:=0 to 127 do del_code(k):=-1;
+@y
+for k:=0 to 255 do del_code(k):=-1;
+@z
+@x module 264
+begin if s<128 then cur_val:=s+single_base
+@y
+begin if s<256 then cur_val:=s+single_base
+@z
+@x ibid
+  for j:=0 to l-1 do buffer[j]:=str_pool[k+j];
+@y
+  for j:=0 to l-1 do buffer[j]:=so(str_pool[k+j]);
+@z
+@x module 289
+@d cs_token_flag==@'10000 {amount added to the |eqtb| location in a
+  token that stands for a control sequence; is a multiple of~256}
+@y
+@d cs_token_flag==@'7777 {amount added to the |eqtb| location in a
+  token that stands for a control sequence; is a multiple of~256, less~1}
+@z
+@x module 293
+  if (info(p)<0)or(c>127) then print_esc("BAD.")
+@y
+  if info(p)<0 then print_esc("BAD.")
+@z
+@x module 341
+@!cat:0..15; {|cat_code(cur_chr)|, usually}
+@y
+@!cat:0..15; {|cat_code(cur_chr)|, usually}
+@!c,@!cc:ASCII_code; {constituents of a possible expanded code}
+@!d:2..3; {number of excess characters in an expanded code}
+@z
+@x module 352
+@<If this |sup_mark| starts a control character...@>=
+begin if (cur_chr=buffer[loc])and(loc<limit) then
+  begin if buffer[loc+1]<@'100 then cur_chr:=buffer[loc+1]+@'100
+  else cur_chr:=buffer[loc+1]-@'100;
+  loc:=loc+2; goto reswitch;
+  end;
+@y
+@ Notice that a code like \.{\^\^8} becomes \.x if not followed by a hex digit.
+ 
+@d is_hex(#)==(((#>="0")and(#<="9"))or((#>="a")and(#<="f")))
+@d hex_to_cur_chr==
+  if c<="9" then cur_chr:=c-"0" @+else cur_chr:=c-"a"+10;
+  if cc<="9" then cur_chr:=16*cur_chr+cc-"0"
+  else cur_chr:=16*cur_chr+cc-"a"+10
+
+@<If this |sup_mark| starts an expanded character...@>=
+begin if cur_chr=buffer[loc] then if loc<limit then
+  begin c:=buffer[loc+1]; @+if c<@'200 then {yes we have an expanded char}
+    begin loc:=loc+2; 
+    if is_hex(c) then if loc<=limit then
+      begin cc:=buffer[loc]; @+if is_hex(cc) then
+        begin incr(loc); hex_to_cur_chr; goto reswitch;
+        end;
+      end;
+    if c<@'100 then cur_chr:=c+@'100 @+else cur_chr:=c-@'100;
+    goto reswitch;
+    end;
+  end;
+@z
+@x module 355
+  begin cur_chr:=buffer[k+1];
+  if cur_chr<@'100 then buffer[k-1]:=cur_chr+@'100
+  else buffer[k-1]:=cur_chr-@'100;
+  limit:=limit-2; first:=first-2;
+  while k<=limit do
+    begin buffer[k]:=buffer[k+2]; incr(k);
+    end;
+  goto start_cs;
+  end;
+@y
+begin c:=buffer[k+1]; @+if c<@'200 then {yes, one is indeed present}
+    begin d:=2;
+    if is_hex(c) then @+if k+2<=limit then
+      begin cc:=buffer[k+2]; @+if is_hex(cc) then incr(d);
+      end;
+    if d>2 then
+      begin hex_to_cur_chr; buffer[k-1]:=cur_chr;
+      end
+    else if c<@'100 then buffer[k-1]:=c+@'100
+    else buffer[k-1]:=c-@'100;
+    limit:=limit-d; first:=first-d;
+    while k<=limit do
+      begin buffer[k]:=buffer[k+d]; incr(k);
+      end;
+    goto start_cs;
+    end;
+  end;
+@z
+@x module 360
+There is one more branch.
+@y
+There is one more branch.
+
+@d end_line_char_inactive == (end_line_char<0)or(end_line_char>255)
+@z
+@x ibid
+    if (end_line_char<0)or(end_line_char>127) then decr(limit)
+@y
+    if end_line_char_inactive then decr(limit)
+@z
+@x modules 362 and 483 and 538 and 1337
+if (end_line_char<0)or(end_line_char>127) then decr(limit)
+@y
+if end_line_char_inactive then decr(limit)
+@z
+@x module 391
+if (info(r)>match_token+127)or(info(r)<match_token) then s:=null
+@y
+if (info(r)>match_token+255)or(info(r)<match_token) then s:=null
+@z
+@x module 407
+   ((cur_chr=str_pool[k])or(cur_chr=str_pool[k]-"a"+"A")) then
+@y
+   ((cur_chr=so(str_pool[k]))or(cur_chr=so(str_pool[k])-"a"+"A")) then
+@z
+@x module 414
+begin scan_seven_bit_int;
+@y
+begin scan_char_num;
+@z
+@x module 432
+|scan_something_internal|:
+
+@<Declare procedures that scan restricted classes of integers@>=
+procedure scan_seven_bit_int;
+begin scan_int;
+if (cur_val<0)or(cur_val>127) then
+  begin print_err("Bad character code");
+@.Bad character code@>
+  help2("The numeric code for a character must be between 0 and 127.")@/
+    ("I changed this one to zero."); int_error(cur_val); cur_val:=0;
+  end;
+end;
+@y
+|scan_something_internal|.
+@z (and I'll interchange modules 434 and 435)
+@x module 442
+if cur_val>127 then
+@y
+if cur_val>255 then
+@z
+@x module 464
+  begin t:=str_pool[k];
+@y
+  begin t:=so(str_pool[k]);
+@z
+@x module 506 (correction needed twice)
+if (cur_cmd>active_char)or(cur_chr>127) then
+@y
+if (cur_cmd>active_char)or(cur_chr>255) then
+@z
+@x module 519
+for j:=str_start[a] to str_start[a+1]-1 do append_to_name(str_pool[j]);
+for j:=str_start[n] to str_start[n+1]-1 do append_to_name(str_pool[j]);
+for j:=str_start[e] to str_start[e+1]-1 do append_to_name(str_pool[j]);
+@y
+for j:=str_start[a] to str_start[a+1]-1 do append_to_name(so(str_pool[j]));
+for j:=str_start[n] to str_start[n+1]-1 do append_to_name(so(str_pool[j]));
+for j:=str_start[e] to str_start[e+1]-1 do append_to_name(so(str_pool[j]));
+@z
+@x module 526
+if (cur_cmd>active_char)or(cur_chr>127) then
+@y
+if (cur_cmd>active_char)or(cur_chr>255) then
+@z
+@x module 603 (change to be made twice)
+  dvi_out(str_pool[k]);
+@y
+  dvi_out(so(str_pool[k]));
+@z
+@x module 617
+  for s:=str_start[str_ptr] to pool_ptr-1 do dvi_out(str_pool[s]);
+@y
+  for s:=str_start[str_ptr] to pool_ptr-1 do dvi_out(so(str_pool[s]));
+@z
+@x module 766
+  begin case str_pool[r_type*8+t+magic_offset] of
+@y
+  begin case so(str_pool[r_type*8+t+magic_offset]) of
+@z
+@x module 780
+@d span_code=128 {distinct from any character}
+@d cr_code=129 {distinct from |span_code| and from any character}
+@y
+@d span_code=256 {distinct from any character}
+@d cr_code=257 {distinct from |span_code| and from any character}
+@z
+@x module 815
+label done,done1,done2,done3,done4;
+@y
+label done,done1,done2,done3,done4,continue;
+@z
+@x module 896
+  else if (type(s)=kern_node)and(subtype(s)=normal) then c:=128
+  else if type(s)=whatsit_node then c:=128
+  else goto done1;
+  if c<128 then if lc_code(c)<>0 then
+    if (lc_code(c)=c)or(uc_hyph>0) then goto done2
+    else goto done1;
+  s:=link(s);
+@y
+  else if (type(s)=kern_node)and(subtype(s)=normal) then goto continue
+  else if type(s)=whatsit_node then goto continue
+  else goto done1;
+  if lc_code(c)<>0 then
+    if (lc_code(c)=c)or(uc_hyph>0) then goto done2
+    else goto done1;
+continue: s:=link(s);
+@z
+@x module 897
+    if c>=128 then goto done3;
+    if (lc_code(c)=0)or(hn=63) then goto done3;
+    hb:=s; incr(hn); hu[hn]:=c; hc[hn]:=lc_code(c)-1;
+@y
+    if lc_code(c)=0 then goto done3;
+    if hn=63 then goto done3;
+    hb:=s; incr(hn); hu[hn]:=c; hc[hn]:=lc_code(c);
+@z
+@x module 898
+if c>=128 then goto done3;
+if (lc_code(c)=0)or(j=63) then goto done3;
+incr(j); hu[j]:=c; hc[j]:=lc_code(c)-1;@/
+@y
+if lc_code(c)=0 then goto done3;
+if j=63 then goto done3;
+incr(j); hu[j]:=c; hc[j]:=lc_code(c);@/
+@z
+@x module 923
+hc[0]:=127; hc[hn+1]:=127; hc[hn+2]:=128; {insert delimiters}
+@y
+hc[0]:=0; hc[hn+1]:=0; hc[hn+2]:=256; {insert delimiters}
+@z
+@x ibid
+  while hc[l]=trie_char(z) do
+@y
+  while hc[l]=qo(trie_char(z)) do
+@z
+@x module 931
+  repeat if str_pool[u]<hc[j] then goto not_found;
+  if str_pool[u]>hc[j] then goto done;
+@y
+  repeat if so(str_pool[u])<hc[j] then goto not_found;
+  if so(str_pool[u])>hc[j] then goto done;
+@z
+@x module 937
+else  begin if (cur_chr>127)or(lc_code(cur_chr)=0) then
+@y
+else  begin if lc_code(cur_chr)=0 then
+@z
+@x ibid
+    begin incr(n); hc[n]:=lc_code(cur_chr)-1;
+@y
+    begin incr(n); hc[n]:=lc_code(cur_chr);
+@z
+@x module 945
+@!init @!trie_c:packed array[trie_pointer] of ASCII_code; {characters to match}
+@y
+@!init @!trie_c:packed array[trie_pointer] of packed_ASCII_code;
+  {characters to match}
+@z
+% In modules 951--954, change "127" to "255" and "128" to "256"
+@x module 952
+trie_link(0):=0; trie_char(0):=0; trie_op(0):=min_quarterword;
+@y
+trie_link(0):=0; trie_char(0):=min_quarterword; trie_op(0):=min_quarterword;
+@z
+@x module 953
+begin c:=trie_c[p];
+@y
+begin c:=so(trie_c[p]);
+@z
+@x module 955
+  begin if trie_link(h+trie_c[q])=0 then goto not_found;
+@y
+  begin if trie_link(h+so(trie_c[q]))=0 then goto not_found;
+@z
+@x module 956
+repeat z:=h+trie_c[q]; trie_back(trie_link(z)):=trie_back(z);
+@y
+repeat z:=h+so(trie_c[q]); trie_back(trie_link(z)):=trie_back(z);
+@z
+@x module 959
+  begin q:=trie_l[p]; c:=trie_c[p];
+  trie_link(z+c):=trie_ref[q]; trie_char(z+c):=c; trie_op(z+c):=trie_o[p];
+@y
+  begin q:=trie_l[p]; c:=so(trie_c[p]);
+  trie_link(z+c):=trie_ref[q]; trie_char(z+c):=qi(c); trie_op(z+c):=trie_o[p];
+@z
+@x module 962
+  begin if cur_chr="." then cur_chr:=128 {edge-of-word delimiter}
+  else  begin cur_chr:=lc_code(cur_chr);
+    if cur_chr=0 then
+      begin print_err("Nonletter");
+@.Nonletter@>
+      help1("(See Appendix H.)"); error; cur_chr:=128;
+      end;
+    end;
+  if k<63 then
+    begin incr(k); hc[k]:=cur_chr-1; hyf[k]:=0; digit_sensed:=false;
+    end;
+  end
+else  begin hyf[k]:=cur_chr-"0";
+  if k<63 then digit_sensed:=true;
+  end
+@y
+  begin if cur_chr="." then cur_chr:=0 {edge-of-word delimiter}
+  else  begin cur_chr:=lc_code(cur_chr);
+    if cur_chr=0 then
+      begin print_err("Nonletter");
+@.Nonletter@>
+      help1("(See Appendix H.)"); error;
+      end;
+    end;
+  if k<63 then
+    begin incr(k); hc[k]:=cur_chr; hyf[k]:=0; digit_sensed:=false;
+    end;
+  end
+  else if k<63 then
+    begin hyf[k]:=cur_chr-"0"; digit_sensed:=true;
+    end;
+  end
+@z
+@x module 963
+  while (p>0)and(c>trie_c[p]) do
+@y
+  while (p>0)and(c>so(trie_c[p])) do
+@z
+@x ibid
+  if (p=0)or(c<trie_c[p]) then
+@y
+  if (p=0)or(c<so(trie_c[p])) then
+@z
+@x module 964
+trie_c[p]:=c; trie_o[p]:=min_quarterword;
+@y
+trie_c[p]:=si(c); trie_o[p]:=min_quarterword;
+@z
+@x module 965
+if hc[1]=127 then hyf[0]:=0;
+if hc[k]=127 then hyf[k]:=0;
+@y
+if hc[1]=0 then hyf[0]:=0;
+if hc[k]=0 then hyf[k]:=0;
+@z
+@x module 966
+h.rh:=0; h.b0:=min_quarterword; h.b1:=0; {|trie_link:=0|,
+  |trie_op:=min_quarterword|, |trie_char:=0|}
+@y
+h.rh:=0; h.b0:=min_quarterword; h.b1:=min_quarterword; {|trie_link:=0|,
+  |trie_op:=min_quarterword|, |trie_char:=qi(0)|}
+@z
+@x module 1034
+if c<128 then
+@y
+@z
+@x ibid
+else space_factor:=1000
+@y
+@z
+@x module 1151
+letter,other_char,char_given: if cur_chr>=128 then c:=cur_chr
+  else  begin c:=ho(math_code(cur_chr));
+@y
+letter,other_char,char_given: begin c:=ho(math_code(cur_chr));
+@z
+@x module 1154
+mmode+letter,mmode+other_char,mmode+char_given: if cur_chr<128 then
+    set_math_char(ho(math_code(cur_chr)))
+  else set_math_char(cur_chr);
+mmode+char_num: begin scan_char_num; cur_chr:=cur_val;
+  if cur_chr<128 then set_math_char(ho(math_code(cur_chr)))
+  else set_math_char(cur_chr);
+@y
+mmode+letter,mmode+other_char,mmode+char_given:
+  set_math_char(ho(math_code(cur_chr)));
+mmode+char_num: begin scan_char_num; cur_chr:=cur_val;
+  set_math_char(ho(math_code(cur_chr)));
+@z
+@x module 1232
+  p:=cur_chr; scan_seven_bit_int; p:=p+cur_val; scan_optional_equals;
+@y
+  p:=cur_chr; scan_char_num; p:=p+cur_val; scan_optional_equals;
+@z
+@x module 1233
+else n:=127
+@y
+else n:=255
+@z
+@x module 1289
+  begin if t>=cs_token_flag then t:=t-active_base;
+  c:=t mod 256;
+  if c<128 then if equiv(b+c)<>0 then t:=256*(t div 256)+equiv(b+c);
+  if t>=cs_token_flag then info(p):=t+active_base
+  else info(p):=t;
+@y
+  begin c:=t mod 256;
+  if equiv(b+c)<>0 then info(p):=t-c+equiv(b+c);
+@z
+@x module 1309
+  w.b0:=str_pool[k]; w.b1:=str_pool[k+1];
+  w.b2:=str_pool[k+2]; w.b3:=str_pool[k+3];
+@y [often qi(so(x))=x, but not e.g. when "quarterwords" are two bytes]
+  w.b0:=qi(so(str_pool[k])); w.b1:=qi(so(str_pool[k+1]));
+  w.b2:=qi(so(str_pool[k+2])); w.b3:=qi(so(str_pool[k+3]));
+@z
+@x module 1310
+  str_pool[k]:=w.b0; str_pool[k+1]:=w.b1;
+  str_pool[k+2]:=w.b2; str_pool[k+3]:=w.b3
+@y
+  str_pool[k]:=si(qo(w.b0)); str_pool[k+1]:=si(qo(w.b1));
+  str_pool[k+2]:=si(qo(w.b2)); str_pool[k+3]:=si(qo(w.b3))
+@z
+@x module 1368
+for k:=str_start[str_ptr] to pool_ptr-1 do dvi_out(str_pool[k]);
+@y
+for k:=str_start[str_ptr] to pool_ptr-1 do dvi_out(so(str_pool[k]));
+@z
+
+360. Major change to allow multiple hyphenation tables.
+I've combined this with the code for a minor change:
+361. New parameters \lefthyphenmin and \righthyphenmin.
+@x module 11 (affects most change files!)
+@!trie_size=8000; {space for hyphenation patterns; should be larger for
+  \.{INITEX} than it is in production versions of \TeX}
+@y
+@!trie_size=8000; {space for hyphenation patterns; should be larger for
+  \.{INITEX} than it is in production versions of \TeX}
+@!trie_op_size=500; {space for ``opcodes'' in the hyphenation patterns}
+@z
+@x module 212
+known as |space_factor|; it holds the current space factor used in spacing
+calculations. In math mode, |aux| is also known as |incompleat_noad|; if
+@y
+known as |space_factor| and |clang|; it holds the current space factor used in
+spacing calculations, and the current language used for hyphenation.
+(The value of |clang| is undefined in restricted horizontal mode.)
+In math mode, |aux| is also known as |incompleat_noad|; if
+@z
+@x ibid
+  @!pg_field,@!aux_field,@!ml_field: integer;
+@y
+  @!pg_field,@!ml_field: integer;
+  @!aux_field: memory_word;
+@z
+@x module 213
+@d prev_depth==aux {the name of |aux| in vertical mode}
+@d space_factor==aux {the name of |aux| in horizontal mode}
+@d incompleat_noad==aux {the name of |aux| in math mode}
+@y
+@d prev_depth==aux.sc {the name of |aux| in vertical mode}
+@d space_factor==aux.hh.lh {part of |aux| in horizontal mode}
+@d clang==aux.hh.rh {the other part of |aux| in horizontal mode}
+@d incompleat_noad==aux.int {the name of |aux| in math mode}
+@z
+@x module 218
+@!a:integer; {auxiliary}
+@y
+@!a:memory_word; {auxiliary}
+@z
+@x module 219
+  if a<=ignore_depth then print("ignored")
+  else print_scaled(a);
+  if nest[p].pg_field<>0 then
+    begin print(", prevgraf ");
+    print_int(nest[p].pg_field); print(" line");
+    if nest[p].pg_field<>1 then print_char("s");
+    end;
+  end;
+1: begin print_nl("spacefactor "); print_int(a);
+  end;
+2: if a<>null then
+  begin print("this will be denominator of:"); show_box(a);
+@y
+  if a.sc<=ignore_depth then print("ignored")
+  else print_scaled(a.sc);
+  if nest[p].pg_field<>0 then
+    begin print(", prevgraf ");
+    print_int(nest[p].pg_field); print(" line");
+    if nest[p].pg_field<>1 then print_char("s");
+    end;
+  end;
+1: begin print_nl("spacefactor "); print_int(a.hh.lh);
+  if m>0 then if a.hh.rh>0 then
+    begin print(", current language "); print_int(a.hh.rh);
+    end;
+  end;
+2: if a.int<>null then
+  begin print("this will be denominator of:"); show_box(a.int);
+@z
+@x modules 236--238
+@d int_pars=50 {total number of integer parameters}
+@y
+@d language_code=50 {current hyphenation table}
+@d left_hyphen_min_code=51 {minimum left hyphenation fragment size}
+@d right_hyphen_min_code=52 {minimum right hyphenation fragment size}
+@d int_pars=53 {total number of integer parameters}
+@z and define/print these new parameters appropriately (mimicking new_line_char)
+@x module 418
+else begin cur_val:=aux;
+  if m=vmode then cur_val_level:=dimen_val@+else cur_val_level:=int_val;
+  end
+@y
+else if m=vmode then
+  begin cur_val:=prev_depth; cur_val_level:=dimen_val;
+  end
+else begin cur_val:=space_factor; cur_val_level:=int_val;
+  end
+@z
+@x module 775
+  begin mode:=-vmode; prev_depth:=nest[nest_ptr-2].aux_field;
+@y
+  begin mode:=-vmode; prev_depth:=nest[nest_ptr-2].aux_field.sc;
+@z
+@x module 786
+begin push_nest; mode:=(-hmode-vmode)-mode; aux:=0;
+@y
+begin push_nest; mode:=(-hmode-vmode)-mode;
+if mode=-hmode then space_factor:=0 @+else prev_depth:=0;
+@z
+@x module 863
+loop@+  begin @<Create an active breakpoint representing the beginning of
+    the paragraph@>;
+@y
+loop@+  begin if threshold>inf_bad then threshold:=inf_bad;
+  if second_pass then @<Initialize for hyphenating a paragraph@>;
+  @<Create an active breakpoint representing the beginning of the paragraph@>;
+@z
+@x module 891
+passes on only about 5 per cent of the paragraphs.
+@y
+passes on only about 5 per cent of the paragraphs.
+
+@<Initialize for hyphenating...@>=
+begin @!init if trie_not_ready then init_trie; @+tini@;@/
+l_hyf:=left_hyphen_min-1;@+if l_hyf<0 then l_hyf:=0;
+r_hyf:=right_hyphen_min-1;@+if r_hyf<0 then r_hyf:=0;
+min_hyf:=l_hyf+r_hyf+2; cur_lang:=0;
+end
+@z
+@x module 892
+@!hyf_char:integer; {hyphen character of the relevant font}
+@y
+@!hyf_char:integer; {hyphen character of the relevant font}
+@!cur_lang:ASCII_code; {current hyphenation table of interest}
+@!l_hyf,@!r_hyf,@!min_hyf:integer; {limits on fragment sizes}
+@z
+@x module 894
+begin s:=link(cur_p);
+@y
+begin if min_hyf>63 then goto done1;
+s:=link(cur_p);
+@z
+@x module 896
+  else if type(s)=whatsit_node then goto continue
+@y
+  else if type(s)=whatsit_node then
+    begin @<Advance \(p)past a whatsit node in the \(p)pre-hyphenation loop@>;
+    goto continue;
+    end
+@z
+@x module 899 (title of this module also changes appropriately)
+if hn<5 then goto done1;
+@y
+if hn<min_hyf then goto done1;
+@z
+@x module 902
+for j:=2 to hn-3 do if odd(hyf[j]) then goto found1;
+@y
+for j:=l_hyf+1 to hn-r_hyf-1 do if odd(hyf[j]) then goto found1;
+@z
+@x module 920
+$p_1\ldots p_k$ by setting |@t$z_1$@>:=@t$p_1$@>| and then, for |1<i<=k|,
+@y
+$p_1\ldots p_k$ by letting $z_0$ be one greater than the relevant language index
+and then, for |1<=i<=k|,
+@z
+@x ibid
+the letters in |hc[(l-k+1)..l@,]|, we perform all of the required operations
+for this pattern by carrying out the following little program: Set
+|v:=trie_op(@t$z_k$@>)|. Then set |hyf[l-hyf_distance[v]]:=@tmax@>(
+hyf[l-hyf_distance[v]], hyf_num[v])|, and |v:=hyf_next[v]|; repeat, if
+necessary, until |v=min_quarterword|.
+@y
+the letters in |hc[(l-k+1)..l@,]| of language |t|,
+we perform all of the required operations
+for this pattern by carrying out the following little program: Set
+|v:=trie_op(@t$z_k$@>)|. Then set |v:=v+op_start[t]|,
+|hyf[l-hyf_distance[v]]:=@tmax@>(hyf[l-hyf_distance[v]], hyf_num[v])|,
+and |v:=hyf_next[v]|; repeat, if necessary, until |v=min_quarterword|.
+@z
+@x module 921
+@!hyf_distance:array[quarterword] of small_number; {position |k-j| of $n_j$}
+@!hyf_num:array[quarterword] of small_number; {value of $n_j$}
+@!hyf_next:array[quarterword] of quarterword; {continuation of this |trie_op|}
+@y
+@!hyf_distance:array[1..trie_op_size] of small_number; {position |k-j| of $n_j$}
+@!hyf_num:array[1..trie_op_size] of small_number; {value of $n_j$}
+@!hyf_next:array[1..trie_op_size] of quarterword; {continuation code}
+@!op_start:array[ASCII_code] of 0..trie_op_size; {offset for current language}
+@z
+@x module 922
+@!v:quarterword; {an index into |hyf_distance|, etc.}
+@y
+@!v:integer; {an index into |hyf_distance|, etc.}
+@z
+@x module 923
+for j:=0 to hn-2 do
+  begin z:=hc[j]; l:=j;
+@y
+if trie_char(cur_lang+1)<>qi(cur_lang) then return; {no patterns for |cur_lang|}
+for j:=0 to hn-r_hyf do
+  begin z:=trie_link(cur_lang+1)+hc[j]; l:=j;
+@z
+@x ibid
+found: hyf[1]:=0; hyf[hn-2]:=0; hyf[hn-1]:=0; hyf[hn]:=0
+@y
+found: for j:=0 to l_hyf do hyf[j]:=0;
+for j:=0 to r_hyf do hyf[hn-j]:=0
+@z
+@x module 924
+repeat i:=l-hyf_distance[v];
+@y
+repeat v:=v+op_start[cur_lang]; i:=l-hyf_distance[v];
+@z
+@x module 930
+h:=hc[1];
+@y
+h:=hc[1]; incr(hn); hc[hn]:=cur_lang;
+@z
+@x ibid
+not_found:
+@y
+not_found: decr(hn)
+@z
+@x module 931
+  goto found;
+@y
+  decr(hn); goto found;
+@z
+@x module 934
+@p procedure new_hyph_exceptions; {enters new exceptions}
+label reswitch, exit, found, not_found, done;
+@y
+@d set_cur_lang==if language<=0 then cur_lang:=0
+  else if language>255 then cur_lang:=0
+  else cur_lang:=language
+
+@p procedure new_hyph_exceptions; {enters new exceptions}
+label reswitch, exit, found, not_found;
+@z
+@x ibid
+begin scan_left_brace; {a left brace must follow \.{\\hyphenation}}
+@y
+begin scan_left_brace; {a left brace must follow \.{\\hyphenation}}
+set_cur_lang;
+@z
+@x module 935
+  spacer,right_brace: begin if n>4 then @<Enter a hyphenation exception@>;
+@y
+  spacer,right_brace: begin if n>1 then @<Enter a hyphenation exception@>;
+@z
+@x module 938
+begin if n>1 then
+@y
+begin if n<63 then
+@z
+@x module 939
+begin str_room(n); h:=0;
+@y
+begin incr(n); hc[n]:=cur_lang; str_room(n); h:=0;
+@z
+@x ibid
+loop@+  begin if p=null then goto done;
+  if info(p)<n-2 then goto done;
+  q:=link(p); free_avail(p); p:=q; {eliminate hyphens that \TeX\ doesn't like}
+  end;
+done: @<Insert the \(p)pair |(s,p)| into the exception table@>;
+@y
+@<Insert the \(p)pair |(s,p)| into the exception table@>;
+@z
+@x module 942
+@p@!init @<Declare procedures for preprocessing hyphenation patterns@>@;
+@y
+@<Declare subprocedures for |line_break|@>=
+@!init @<Declare procedures for preprocessing hyphenation patterns@>@;
+@z
+@x module 943
+@d quarterword_diff=max_quarterword-min_quarterword
+@d trie_op_hash_size=quarterword_diff+quarterword_diff {double}
+
+@<Glob...@>=
+@!init@! trie_op_hash:array[0..trie_op_hash_size] of quarterword;
+  {trie op codes for triples}
+tini@;@/
+@t\hskip1em@>@!trie_op_ptr:quarterword; {highest |trie_op| assigned}
+@y
+@<Glob...@>=
+@!init@! trie_op_hash:array[-trie_op_size..trie_op_size] of 0..trie_op_size;
+  {trie op codes for quadruples}
+@!trie_used:array[ASCII_code] of quarterword;
+  {largest opcode used so far for this language}
+@!trie_op_lang:array[1..trie_op_size] of ASCII_code;
+  {language part of a hashed quadruple}
+@!trie_op_val:array[1..trie_op_size] of quarterword;
+  {opcode corresponding to a hashed quadruple}
+@!trie_op_ptr:0..trie_op_size; {number of stored ops so far}
+tini
+@z
+@x module 944 should be entirely replaced
+@y by the following code:
+@ It's tempting to remove the |overflow| stops in the following procedure;
+|new_trie_op| could return |min_quarterword| (thereby simply ignoring
+part of a hyphenation pattern) instead of aborting the job. However, that would
+lead to different hyphenation results on different installations of \TeX\
+using the same patterns. The |overflow| stops are necessary for portability
+of patterns.
+
+@<Declare procedures for preprocessing hyph...@>=
+function new_trie_op(@!d,@!n:small_number;@!v:quarterword):quarterword;
+label exit;
+var h:-trie_op_size..trie_op_size; {trial hash location}
+@!u:quarterword; {trial op code}
+@!l:0..trie_op_size; {pointer to stored data}
+begin h:=abs(n+313*d+361*v+1009*cur_lang) mod (trie_op_size+trie_op_size)
+  - trie_op_size;
+loop@+  begin l:=trie_op_hash[h];
+  if l=0 then {empty position found for a new op}
+    begin if trie_op_ptr=trie_op_size then
+      overflow("pattern memory ops",trie_op_size);
+    u:=trie_used[cur_lang];
+    if u=max_quarterword then
+      overflow("pattern memory ops per language",
+        max_quarterword-min_quarterword);
+    incr(trie_op_ptr); incr(u); trie_used[cur_lang]:=u;
+    hyf_distance[trie_op_ptr]:=d;
+    hyf_num[trie_op_ptr]:=n; hyf_next[trie_op_ptr]:=v;
+    trie_op_lang[trie_op_ptr]:=cur_lang; trie_op_hash[h]:=trie_op_ptr;
+    trie_op_val[trie_op_ptr]:=u; new_trie_op:=u; return;
+    end;
+  if (hyf_distance[l]=d)and(hyf_num[l]=n)and(hyf_next[l]=v)
+   and(trie_op_lang[l]=cur_lang) then
+    begin new_trie_op:=trie_op_val[l]; return;
+    end;
+  if h>-trie_op_size then decr(h)@+else h:=trie_op_size;
+  end;
+exit:end;
+@z
+@x module 945: move the code from this module into 946, and introduce new code:
+@y
+@ After |new_trie_op| has compressed the necessary opcode information,
+plenty of information is available to unscramble the data into the
+final form needed by our hyphenation algorithm.
+
+@<Sort the hyphenation op tables into proper order@>=
+op_start[0]:=-min_quarterword;
+for j:=1 to 255 do op_start[j]:=op_start[j-1]+qo(trie_used[j-1]);
+for j:=1 to trie_op_ptr do
+  trie_op_hash[j]:=op_start[trie_op_lang[j]]+trie_op_val[j]; {destination}
+for j:=1 to trie_op_ptr do while trie_op_hash[j]>j do
+  begin k:=trie_op_hash[j];@/
+  t:=hyf_distance[k]; hyf_distance[k]:=hyf_distance[j]; hyf_distance[j]:=t;@/
+  t:=hyf_num[k]; hyf_num[k]:=hyf_num[j]; hyf_num[j]:=t;@/
+  t:=hyf_next[k]; hyf_next[k]:=hyf_next[j]; hyf_next[j]:=t;@/
+  trie_op_hash[j]:=trie_op_hash[k]; trie_op_hash[k]:=k;
+  end
+@z
+@x module 949: Move this code to just after the new module 945!
+mentioned so far, let's write a procedure that does the initialization.
+
+@<Declare procedures for preprocessing hyph...@>=
+procedure init_pattern_memory; {gets ready to build a linked trie}
+var h:0..trie_op_hash_size; {an index into |trie_op_hash|}
+@!p:trie_pointer; {an index into |trie_hash|}
+begin for h:=0 to trie_op_hash_size do trie_op_hash[h]:=min_quarterword;
+trie_op_ptr:=min_quarterword; trie_root:=0; trie_c[0]:=0; trie_ptr:=0;
+for p:=0 to trie_size do trie_hash[p]:=0;
+end;
+@y
+mentioned so far, let's write down the code that gets them started.
+
+@<Initialize table entries...@>=
+for k:=-trie_op_size to trie_op_size do trie_op_hash[k]:=0;
+for k:=0 to 255 do trie_used[k]:=min_quarterword;
+trie_op_ptr:=0;
+@z
+@x module 950
+@t\hskip1em@>@!trie_min:trie_pointer;
+  {all locations |<=trie_min| are vacant in |trie|}
+tini@;@/
+@t\hskip1em@>@!trie_max:trie_pointer; {largest location used in |trie|}
+@y
+@t\hskip10pt@>@!trie_min:array[ASCII_code] of trie_pointer;
+  {the first possible slot for each character}
+@t\hskip10pt@>@!trie_max:trie_pointer; {largest location used in |trie|}
+@t\hskip10pt@>@!trie_not_ready:boolean; {is the trie still in linked form?}
+tini
+@z
+@x modules 951 and 952
+@ Here is how these data structures are initialized.
+
+@<Declare procedures for preprocessing hyph...@>=
+procedure init_trie_memory; {gets ready to pack into |trie|}
+var p:trie_pointer; {index into |trie_ref|, |trie|, |trie_taken|}
+begin for p:=0 to trie_ptr do trie_ref[p]:=0;
+trie_max:=256; trie_min:=256; trie_link(0):=1; trie_taken[0]:=false;
+trie_link(trie_size):=0; trie_back(0):=trie_size; {wrap around}
+for p:=1 to 256 do
+  begin trie_back(p):=p-1; trie_link(p):=p+1; trie_taken[p]:=false;
+  end;
+end;
+
+@ Each time \.{\\patterns} appears, it overrides any patterns that were
+entered earlier, so the arrays are not initialized until \TeX\ sees
+\.{\\patterns}. However, some of the global variables must be
+initialized when \.{INITEX} is loaded, in case the user never mentions
+any \.{\\patterns}.
+
+@<Initialize table entries...@>=
+trie_op_ptr:=min_quarterword;@/
+trie_link(0):=0; trie_char(0):=min_quarterword; trie_op(0):=min_quarterword;
+for k:=1 to 255 do trie[k]:=trie[0];
+trie_max:=255;
+@y
+@ Each time \.{\\patterns} appears, it contributes further patterns to
+the future trie, which will be built only when hyphenation is attempted or
+when a format file is dumped. The boolean variable |trie_not_ready|
+will change to |false| when the trie is compressed; this will disable
+further patterns.
+
+@<Initialize table entries...@>=
+trie_not_ready:=true; trie_root:=0; trie_c[0]:=si(0); trie_ptr:=0;
+
+@ Here is how the trie-compression data structures are initialized.
+If storage is tight, it would be possible to overlap |trie_op_hash|,
+|trie_op_lang|, and |trie_op_val| with |trie|, |trie_hash|, and |trie_taken|,
+because we finish with the former just before we need the latter.
+
+@<Get ready to compress the trie@>=
+@<Sort the hyphenation...@>;
+for p:=0 to trie_size do trie_hash[p]:=0;
+trie_root:=compress_trie(trie_root); {identify equivalent subtries}
+for p:=0 to trie_ptr do trie_ref[p]:=0;
+for p:=0 to 255 do trie_min[p]:=p+1;
+trie_link(0):=1; trie_max:=0
+@z
+@x module 953
+begin c:=so(trie_c[p]);
+if c<trie_min then trie_min:=c;
+if trie_min=0 then z:=trie_link(trie_size)
+else z:=trie_link(trie_min-1); {get the first conceivably good hole}
+loop@+  begin if z<c then goto not_found;
+  h:=z-c;@/
+@y
+@!l,@!r:trie_pointer; {left and right neighbors}
+@!ll:1..256; {upper limit of |trie_min| updating}
+begin c:=so(trie_c[p]);
+z:=trie_min[c]; {get the first conceivably good hole}
+loop@+  begin h:=z-c;@/
+@z
+@x module 956
+repeat z:=h+so(trie_c[q]); trie_back(trie_link(z)):=trie_back(z);
+trie_link(trie_back(z)):=trie_link(z); trie_link(z):=0; q:=trie_r[q];
+@y
+repeat z:=h+so(trie_c[q]); l:=trie_back(z); r:=trie_link(z);
+trie_back(r):=l; trie_link(l):=r; trie_link(z):=0;
+if l<256 then
+  begin if z<256 then ll:=z @+else ll:=256;
+  repeat trie_min[l]:=r; incr(l);
+  until l=ll;
+  end;
+q:=trie_r[q];
+@z
+@x module 958 is entirely replaced
+@y by the following new code:
+@ When the whole trie has been allocated into the sequential table, we
+must go through it once again so that |trie| contains the correct
+information. Null pointers in the linked trie will be represented by the
+value~0, which properly implements an ``empty'' family.
+
+@<Move the data into |trie|@>=
+h.rh:=0; h.b0:=min_quarterword; h.b1:=min_quarterword; {|trie_link:=0|,
+  |trie_op:=min_quarterword|, |trie_char:=qi(0)|}
+if trie_root=0 then {no patterns were given}
+  begin for r:=0 to 256 do trie[r]:=h;
+  trie_max:=256;
+  end
+else begin trie_fix(trie_root); {this fixes the non-holes in |trie|}
+  r:=0; {now we will zero out all the holes}
+  repeat s:=trie_link(r); trie[r]:=h; r:=s;
+  until r>trie_max;
+  end;
+trie_char(0):=qi("?"); {make |trie_char(c)<>c| for all |c|}
+@z
+@x module 960
+@!r,@!s:trie_pointer; {used to clean up the packed |trie|}
+@!h:two_halves; {template used to zero out |trie|'s holes}
+begin scan_left_brace; {a left brace must follow \.{\\patterns}}
+init_pattern_memory;@/
+@<Enter all of the patterns into a linked trie, until coming to a right
+  brace@>;
+trie_root:=compress_trie(trie_root); {compress the trie}
+@<Pack the trie@>;
+end;
+@y
+begin if trie_not_ready then
+  begin set_cur_lang; scan_left_brace; {a left brace must follow \.{\\patterns}}
+  @<Enter all of the patterns into a linked trie, until coming to a right
+  brace@>;
+  end
+else begin print_err("Too late for "); print_esc("patterns");
+  help1("All patterns must be given before typesetting begins.");
+  error; link(garbage):=scan_toks(false,false); flush_list(def_ref);
+  end;
+end;
+@z
+@x module 963
+q:=0;
+while l<k do
+  begin incr(l); c:=hc[l]; p:=trie_l[q]; first_child:=true;
+@y
+q:=0; hc[0]:=cur_lang;
+while l<=k do
+  begin c:=hc[l]; incr(l); p:=trie_l[q]; first_child:=true;
+@z
+@x module 966 now says that the first call ``takes'' location 1,
+@y and the Pascal code in this module is entirely replaced by the following:
+@<Declare procedures for preprocessing hyphenation patterns@>=
+procedure init_trie;
+var @!p:trie_pointer; {pointer for initialization}
+@!j,@!k,@!t:integer; {all-purpose registers for initialization}
+@!r,@!s:trie_pointer; {used to clean up the packed |trie|}
+@!h:two_halves; {template used to zero out |trie|'s holes}
+begin @<Get ready to compress the trie@>;
+if trie_root<>0 then
+  begin first_fit(trie_root); trie_pack(trie_root);
+  end;
+@<Move the data into |trie|@>;
+trie_not_ready:=false;
+end;
+@z
+@x module 1033 gets new code before main_loop_1
+@y
+if mode>0 then if language<>clang then fix_language;
+@z
+@x modules 1091 and 1200
+push_nest; mode:=hmode; space_factor:=1000;
+@y
+push_nest; mode:=hmode; space_factor:=1000; clang:=0;
+@z
+@x module 1324
+for k:=0 to trie_max do dump_hh(trie[k]);
+dump_int(trie_op_ptr);
+for k:=min_quarterword+1 to trie_op_ptr do
+  begin dump_int(hyf_distance[k]);
+  dump_int(hyf_num[k]);
+  dump_int(hyf_next[k]);
+  end;
+print_ln; print_int(hyph_count); print(" hyphenation exception");
+if hyph_count<>1 then print_char("s");
+print_nl("Hyphenation trie of length "); print_int(trie_max);
+@.Hyphenation trie...@>
+print(" has "); print_int(qo(trie_op_ptr)); print(" op");
+if trie_op_ptr<>min_quarterword+1 then print_char("s")
+@y
+print_ln; print_int(hyph_count); print(" hyphenation exception");
+if hyph_count<>1 then print_char("s");
+if trie_not_ready then init_trie;
+dump_int(trie_max);
+for k:=0 to trie_max do dump_hh(trie[k]);
+dump_int(trie_op_ptr);
+for k:=1 to trie_op_ptr do
+  begin dump_int(hyf_distance[k]);
+  dump_int(hyf_num[k]);
+  dump_int(hyf_next[k]);
+  end;
+print_nl("Hyphenation trie of length "); print_int(trie_max);
+@.Hyphenation trie...@>
+print(" has "); print_int(trie_op_ptr); print(" op");
+if trie_op_ptr<>1 then print_char("s");
+print(" out of "); print_int(trie_op_size);
+for k:=255 downto 0 do if trie_used[k]>min_quarterword then
+  begin print_nl("  "); print_int(qo(trie_used[k]));
+  print(" for language "); print_int(k);
+  dump_int(k); dump_int(qo(trie_used[k]));
+  end
+@z
+@x module 1325
+undump_size(0)(trie_size)('trie size')(trie_max);
+for k:=0 to trie_max do undump_hh(trie[k]);
+undump(min_quarterword)(max_quarterword)(trie_op_ptr);
+for k:=min_quarterword+1 to trie_op_ptr do
+  begin undump(0)(63)(hyf_distance[k]); {a |small_number|}
+  undump(0)(63)(hyf_num[k]);
+  undump(min_quarterword)(max_quarterword)(hyf_next[k]);
+  end
+@y
+undump_size(0)(trie_size)('trie size')(j); {|trie_max|}
+for k:=0 to j do undump_hh(trie[k]);
+undump_size(0)(trie_op_size)('trie op size')(j); {|trie_op_ptr|}
+for k:=1 to j do
+  begin undump(0)(63)(hyf_distance[k]); {a |small_number|}
+  undump(0)(63)(hyf_num[k]);
+  undump(min_quarterword)(max_quarterword)(hyf_next[k]);
+  end;
+k:=256;
+while j>0 do
+  begin undump(0)(k-1)(k); undump(1)(j)(x); j:=j-x; op_start[k]:=qo(j);
+  end;
+@!init trie_not_ready:=false @+tini
+@z
+@x module 1341 gets two new definitions
+@y
+@d language_node=4 {|subtype| in whatsits that change the current language}
+@d stored_language(#)==mem[#+1].int {language number, in the range |0..255|}
+@z
+@x module 1344 gets a new definition and a new Pascal statement
+@y
+@d set_language_code=5 {command modifier for \.{\\setlanguage}}
+primitive("setlanguage",extension,set_language_code);@/
+@!@:set_language_}{\.{\\setlanguage} primitive@>
+@z
+@x module 1346 gets a new case
+@y
+  set_language_code:print_esc("setlanguage");
+@z
+@x module 1348 gets a new case
+@y
+set_language_code:@<Implement \.{\\setlanguage}@>;
+@z
+@x module 1356 gets a new case
+@y
+language_node:begin print_esc("setlanguage");
+  print_int(stored_language(p));
+  end;
+@z
+% in modules 1357 and 1358, change "close_node" to "close_node,language_node".
+@x module 1362 becomes two modules
+@ @<Advance \(p)past a whatsit node in the |line_break| loop@>=do_nothing
+@y
+@ @<Advance \(p)past a whatsit node in the \(l)|line_break| loop@>=
+if subtype(cur_p)=language_node then cur_lang:=stored_language(cur_p)
+
+@ @<Advance \(p)past a whatsit node in the \(p)pre-hyphenation loop@>=
+if subtype(s)=language_node then cur_lang:=stored_language(s)
+@z and old module 1367 is moved to just before the old module 1378
+@x module 1373 gets a new case
+@y
+language_node:do_nothing;
+@z
+@x new modules before the system-dependent changes (i.e. before the old 1376)
+@y
+@ @<Implement \.{\\setlanguage}@>=
+if abs(mode)<>hmode then report_illegal_case
+else begin new_whatsit(language_node,small_node_size);
+  scan_int;
+  if cur_val<=0 then clang:=0
+  else if cur_val>255 then clang:=0
+  else clang:=cur_val;
+  stored_language(tail):=clang;
+  end
+
+@ Finally, we need a subroutine that comes into play when a character of
+a non-|clang| language is being appended to the current paragraph.
+
+@<Declare action...@>=
+procedure fix_language;
+var @!l:ASCII_code; {the new current language}
+begin if language<=0 then l:=0
+else if language>255 then l:=0
+else l:=language;
+if l<>clang then
+  begin new_whatsit(language_node,small_node_size);
+  stored_language(tail):=l; clang:=l;
+  end;
+end;
+@z
+
+362. Major extension to ligature capability.
+@x module 143
+a linked list of character nodes for those characters.
+@y
+a linked list of character nodes for all original characters that have been
+deleted. (This list might be empty if the characters that generated the
+ligature were retained in other nodes.)
+
+The |subtype| field is 0, plus 2 and/or 1 if the original source of the
+ligature included implicit left and/or right boundaries.
+@z
+@x in module 144 add the following procedure to the existing code
+@y
+function new_lig_item(@!c:quarterword):pointer;
+var p:pointer; {the new node}
+begin p:=get_node(small_node_size); character(p):=c; lig_ptr(p):=null;
+new_lig_item:=p;
+end;
+@z
+@x module 193
+font_in_short_display:=font(lig_char(p));
+short_display(lig_ptr(p)); print_char(")");
+@y
+if subtype(p)>1 then print_char("|");
+font_in_short_display:=font(lig_char(p)); short_display(lig_ptr(p));
+if odd(subtype(p)) then print_char("|");
+print_char(")");
+end
+@z
+@x modules 208 and 209
+@d radical=65 {square root and similar signs ( \.{\\radical} )}
+@y
+@d no_boundary=65 {suppress boundary ligatures ( \.{\\noboundary} )}
+@d radical=66 {square root and similar signs ( \.{\\radical} )}
+@z and so on, adding 1 to each definition until getting to max_command=100
+@x module 265 gets a new statement
+@y
+primitive("noboundary",no_boundary,0);@/
+@!@:no_boundary_}{\.{\\noboundary} primitive@>
+@z
+@x module 266 gets a new case
+@y
+no_boundary:print_esc("noboundary");
+@z
+@x module 545 is entirely replaced
+@y by the following new specifications:
+@ The |lig_kern| array contains instructions in a simple programming language
+that explains what to do for special letter pairs. Each word in this array is a
+|@!lig_kern_command| of four bytes.
+
+\yskip\hang first byte: |skip_byte|, indicates that this is the final program
+  step if the byte is 128 or more, otherwise the next step is obtained by
+  skipping this number of intervening steps.\par
+\hang second byte: |next_char|, ``if |next_char| follows the current character,
+  then perform the operation and stop, otherwise continue.''\par
+\hang third byte: |op_byte|, indicates a ligature step if less than~128,
+  a kern step otherwise.\par
+\hang fourth byte: |remainder|.\par
+\yskip\noindent
+In a kern step, an
+additional space equal to |kern[256*(op_byte-128)+remainder]| is inserted
+between the current character and |next_char|. This amount is
+often negative, so that the characters are brought closer together
+by kerning; but it might be positive.
+
+There are eight kinds of ligature steps, having |op_byte| codes $4a+2b+c$ where
+$0\le a\le b+c$ and $0\le b,c\le1$. The character whose code is
+|remainder| is inserted between the current character and |next_char|;
+then the current character is deleted if $b=0$, and |next_char| is
+deleted if $c=0$; then we pass over $a$~characters to reach the next
+current character (which may have a ligature/kerning program of its own).
+
+If the very first instruction of the |lig_kern| array has |skip_byte=255|,
+the |next_char| byte is the so-called right boundary character of this font;
+the value of |next_char| need not lie between |bc| and~|ec|.
+If the very last instruction of the |lig_kern| array has |skip_byte=255|,
+there is a special ligature/kerning program for a left boundary character,
+beginning at location |256*op_byte+remainder|.
+The interpretation is that \TeX\ puts implicit boundary characters
+before and after each consecutive string of characters from the same font.
+These implicit characters do not appear in the output, but they can affect
+ligatures and kerning.
+
+If the very first instruction of a character's |lig_kern| program has
+|skip_byte>128|, the program actually begins in location
+|256*op_byte+remainder|. This feature allows access to large |lig_kern|
+arrays, because the first instruction must otherwise
+appear in a location |<=255|.
+
+Any instruction with |skip_byte>128| in the |lig_kern| array must have
+|256*op_byte+remainder<nl|. If such an instruction is encountered during
+normal program execution, it denotes an unconditional halt; no ligature
+command is performed.
+
+@d stop_flag=qi(128) {value indicating `\.{STOP}' in a lig/kern program}
+@d kern_flag=qi(128) {op code for a kern step}
+@d skip_byte(#)==#.b0
+@d next_char(#)==#.b1
+@d op_byte(#)==#.b2
+@d rem_byte(#)==#.b3
+@z
+@x module 549
+@<Glob...@>=
+@y
+@d non_char==qi(256) {a |halfword| code that can't match a real character}
+@d non_address==font_mem_size {a spurious |font_index|}
+
+@<Glob...@>=
+@z
+@x module 548 gets a new type definition
+@y
+@!font_index=0..font_mem_size;
+@z
+@x module 549
+  {current \.{\\skewchar} values}
+@y
+  {current \.{\\skewchar} values}
+@!bchar_label:array[internal_font_number] of font_index;
+  {start of |lig_kern| program for left boundary character,
+  |non_address| if there is none}
+@!font_bchar:array[internal_font_number] of min_quarterword..non_char;
+  {right boundary character, |non_char| if there is none}
+@!font_false_bchar:array[internal_font_number] of min_quarterword..non_char;
+  {|font_bchar| if it doesn't exist in the font, otherwise |non_char|}
+@z
+@x module 557
+@d char_kern_end(#)==rem_byte(#)].sc
+@y NOTE: Optimize kern_base_offset in your change file! It's a constant.
+@d char_kern_end(#)==256*op_byte(#)+rem_byte(#)].sc
+@d kern_base_offset==256*(kern_flag)
+@d lig_kern_restart_end(#)==256*op_byte(#)+rem_byte(#)+32768-kern_base_offset
+@d lig_kern_restart(#)==lig_kern_base[#]+lig_kern_restart_end
+@z
+@x module 560
+@!z:scaled; {the design size or the ``at'' size}
+@y
+@!bch_label:integer; {left boundary start location, or infinity}
+@!bchar:0..256; {right boundary character, or 256}
+@!z:scaled; {the design size or the ``at'' size}
+@z
+@x module 566
+kern_base[f]:=lig_kern_base[f]+nl;
+exten_base[f]:=kern_base[f]+nk;
+@y
+kern_base[f]:=lig_kern_base[f]+nl-kern_base_offset;
+exten_base[f]:=kern_base[f]+kern_base_offset+nk;
+@z
+@x module 573: The entire module is replaced
+@y by the following code.
+@ @d check_existence(#)==@t@>@;@/
+  begin check_byte_range(#);
+  qw:=char_info(f)(#); {N.B.: not |qi(#)|}
+  if not char_exists(qw) then abort;
+  end
+
+@<Read ligature/kern program@>=
+bch_label:=@'77777; bchar:=256;
+if nl>0 then
+  begin for k:=lig_kern_base[f] to kern_base[f]+kern_base_offset-1 do
+    begin store_four_quarters(font_info[k].qqqq);
+    if a>128 then
+      begin if 256*c+d>=nl then abort;
+      if a=255 then if k=lig_kern_base[f] then bchar:=b;
+      end
+    else begin if b<>bchar then check_existence(b);
+      if c<128 then check_existence(d) {check ligature}
+      else if 256*(c-128)+d>=nk then abort; {check kern}
+      if a<128 then if k-lig_kern_base[f]+a+1>=nl then abort;
+      end;
+    end;
+  if a=255 then bch_label:=256*c+d;
+  end;
+for k:=kern_base[f]+kern_base_offset to exten_base[f]-1 do
+  store_scaled(font_info[k].sc);
+@z
+@x module 574 (actually a bugfix)
+  if a<>0 then check_byte_range(a);
+  if b<>0 then check_byte_range(b);
+  if c<>0 then check_byte_range(c);
+  check_byte_range(d);
+@y
+  if a<>0 then check_existence(a);
+  if b<>0 then check_existence(b);
+  if c<>0 then check_existence(c);
+  check_existence(d);
+@z
+@x module 576
+font_name[f]:=nom;
+@y
+if bch_label<nl then bchar_label[f]:=bch_label+lig_kern_base[f]
+else bchar_label[f]:=non_address;
+font_bchar[f]:=qi(bchar);
+font_false_bchar[f]:=qi(bchar);
+if bchar<=ec then if bchar>=bc then
+  begin qw:=char_info(f)(bchar); {N.B.: not |qi(bchar)|}
+  if char_exists(qw) then font_false_bchar[f]:=non_char;
+  end;
+font_name[f]:=nom;
+@z
+@x module 708 (slight but optional optimization)
+continue: if (qo(y)>=font_bc[g])and(qo(y)<=font_ec[g]) then
+  begin q:=char_info(g)(y);
+@y
+if (qo(y)>=font_bc[g])and(qo(y)<=font_ec[g]) then
+  begin continue: q:=char_info(g)(y);
+@z
+@x module 740 (another bugfix)
+  i:=char_info(f)(y);
+@y
+  i:=char_info(f)(y);
+  if not char_exists(i) then goto done;
+@z
+@x module 741
+    repeat cur_i:=font_info[a].qqqq;
+    if qo(next_char(cur_i))=skew_char[cur_f] then
+      begin if op_bit(cur_i)>=kern_flag then
+        s:=char_kern(cur_f)(cur_i);
+      goto done1;
+      end;
+    incr(a);
+    until stop_bit(cur_i)>=stop_flag;
+@y
+    cur_i:=font_info[a].qqqq;
+    if skip_byte(cur_i)>stop_flag then
+      begin a:=256*(qo(op_byte(cur_i)))+rem_byte(cur_i);
+      cur_i:=font_info[a].qqqq;
+      end;
+    loop begin if qo(next_char(cur_i))=skew_char[cur_f] then
+        begin if op_byte(cur_i)>=kern_flag then
+          if skip_byte(cur_i)<=stop_flag then s:=char_kern(cur_f)(cur_i);
+        goto done1;
+        end;
+      if skip_byte(cur_i)>=stop_flag then goto done1
+      else a:=a+qo(skip_byte(cur_i))+1;
+      cur_i:=font_info[a].qqqq;
+      end;
+@z
+@x module 749 (yet another bugfix of the same type!)
+@!p,@!v,@!x,@!y,@!z:pointer; {temporary registers for box construction}
+@y
+@!p,@!v,@!x,@!y,@!z:pointer; {temporary registers for box construction}
+@!c:quarterword;@+@!i:four_quarters; {registers for character examination}
+@z
+@x ibid
+    begin cur_c:=rem_byte(cur_i); character(nucleus(q)):=cur_c;
+    cur_i:=char_info(cur_f)(cur_c);
+@y
+    begin c:=rem_byte(cur_i); i:=char_info(cur_f)(c);
+    if char_exists(i) then
+      begin cur_c:=c; cur_i:=i; character(nucleus(q)):=c;
+      end;
+@z
+@x module 752
+@!p:pointer; {temporary register for list manipulation}
+@y
+@!p,@!r:pointer; {temporary registers for list manipulation}
+@z
+@x ibid
+        repeat cur_i:=font_info[a].qqqq;@/
+        @<If instruction |cur_i| is a kern with |cur_c|,
+         attach the kern after |q| and |return|;
+         or if it is a ligature with |cur_c|, combine
+         noads |q| and |p| and |goto restart|@>;
+        incr(a);
+        until stop_bit(cur_i)>=stop_flag;
+@y
+        cur_i:=font_info[a].qqqq;
+        if skip_byte(cur_i)>stop_flag then
+          begin a:=lig_kern_restart(cur_f)(cur_i);
+          cur_i:=font_info[a].qqqq;
+          end;
+        loop@+ begin @<If instruction |cur_i| is a kern with |cur_c|, attach
+            the kern after~|q|; or if it is a ligature with |cur_c|, combine
+            noads |q| and~|p| appropriately; then |return| if the cursor has
+            moved past a noad, or |goto restart|@>;
+          if skip_byte(cur_i)>=stop_flag then return;
+          a:=a+qo(skip_byte(cur_i))+1;
+          cur_i:=font_info[a].qqqq;
+          end;
+@z
+@x The entire code of module 753 is revised
+@y and should be replaced by the following:
+@ Note that a ligature between an |ord_noad| and another kind of noad
+is replaced by an |ord_noad|, when the two noads collapse into one.
+But we could make a parenthesis (say) change shape when it follows
+certain letters. Presumably a font designer will define such
+ligatures only when this convention makes sense.
+
+\chardef\?='174 % vertical line to indicate character retention
+
+@<If instruction |cur_i| is a kern with |cur_c|, ...@>=
+if next_char(cur_i)=cur_c then if skip_byte(cur_i)<=stop_flag then
+  if op_byte(cur_i)>=kern_flag then
+    begin p:=new_kern(char_kern(cur_f)(cur_i));
+    link(p):=link(q); link(q):=p; return;
+    end
+  else  begin check_interrupt; {allow a way out of infinite ligature loop}
+      case op_byte(cur_i) of
+   qi(1),qi(5): character(nucleus(q)):=rem_byte(cur_i); {\.{=:\?}, \.{=:\?>}}
+   qi(2),qi(6): character(nucleus(p)):=rem_byte(cur_i); {\.{\?=:}, \.{\?=:>}}
+   qi(3),qi(7),qi(11):begin r:=new_noad; {\.{\?=:\?}, \.{\?=:\?>}, \.{\?=:\?>>}}
+       character(nucleus(r)):=rem_byte(cur_i);
+       fam(nucleus(r)):=fam(nucleus(q));@/
+       link(q):=r; link(r):=p;
+       if op_byte(cur_i)<qi(11) then math_type(nucleus(r)):=math_char
+       else math_type(nucleus(r)):=math_text_char; {prevent combination}
+       end;
+     othercases begin link(q):=link(p);
+       character(nucleus(q)):=rem_byte(cur_i); {\.{=:}}
+       mem[subscr(q)]:=mem[subscr(p)]; mem[supscr(q)]:=mem[supscr(p)];@/
+       free_node(p,noad_size);
+       end
+     endcases;
+     if op_byte(cur_i)>qi(3) then return;
+     math_type(nucleus(q)):=math_char; goto restart;
+     end
+@z
+@x module 862
+@!q,@!r,@!s:pointer; {miscellaneous nodes of temporary interest}
+@y
+@!q,@!r,@!s,@!prev_s:pointer; {miscellaneous nodes of temporary interest}
+@z
+@x module 892
+nodes $p_a$ and~$p_b$ in the description above are placed into variables
+@y
+nodes $p_{a-1}$ and~$p_b$ in the description above are placed into variables
+@z
+@x ibid
+@!hc:array[0..65] of halfword; {word to be hyphenated}
+@y
+@!hc:array[0..65] of 0..256; {word to be hyphenated}
+@z
+@x ibid
+@!hu:array[1..63] of ASCII_code; {like |hc|, before conversion to lowercase}
+@y
+@!hu:array[0..63] of 0..256; {like |hc|, before conversion to lowercase}
+@z
+@x module 894
+s:=link(cur_p);
+@y
+prev_s:=cur_p; s:=link(prev_s);
+@z
+@x module 895
+label done,found,not_found,found1,exit;
+@y
+label common_ending,done,found,found1,not_found,not_found+1,exit;
+@z
+@x module 896
+  else if type(s)=ligature_node then
+    begin q:=lig_ptr(s); c:=qo(character(q)); hf:=font(q);
+    end
+@y
+  else if type(s)=ligature_node then
+    if lig_ptr(s)=null then goto continue
+    else begin q:=lig_ptr(s); c:=qo(character(q)); hf:=font(q);
+      end
+@z
+@x ibid
+continue: s:=link(s);
+@y
+continue: prev_s:=s; s:=link(prev_s);
+@z
+@x ibid
+ha:=s
+@y
+ha:=prev_s
+@z
+@x module 898
+begin j:=hn; q:=lig_ptr(s);
+if font(q)<>hf then goto done3;
+repeat c:=qo(character(q));
+if lc_code(c)=0 then goto done3;
+if j=63 then goto done3;
+incr(j); hu[j]:=c; hc[j]:=lc_code(c);@/
+q:=link(q);
+until q=null;
+@y
+begin if font(lig_char(s))<>hf then goto done3;
+j:=hn; q:=lig_ptr(s);
+while q>null do
+  begin c:=qo(character(q));
+  if lc_code(c)=0 then goto done3;
+  if j=63 then goto done3;
+  incr(j); hu[j]:=c; hc[j]:=lc_code(c);@/
+  q:=link(q);
+  end;
+@z
+@x module 900 gets three new global variables
+@y
+@!init_list:pointer; {list of punctuation characters preceding the word}
+@!init_lig:boolean; {does |init_list| represent a ligature?}
+@!init_lft:boolean; {if so, did the ligature involve a left boundary?}
+@z
+@x module 901
+@!q,@!r,@!s:pointer; {temporary registers for list manipulation}
+@y
+@!p,@!q,@!r,@!s:pointer; {temporary registers for list manipulation}
+@!bchar:halfword; {right boundary character of hyphenated word, or |non_char|}
+@z
+@x module 903 should be entirely replaced
+@y by the following:
+@ If hyphens are in fact going to be inserted, \TeX\ first deletes the
+subsequence of nodes between |ha| and~|hb|. An attempt is made to
+preserve the effect that implicit boundary characters and punctuation marks
+had on ligatures inside the hyphenated word, by storing a left boundary or
+preceding character in |hu[0]| and by storing a possible right boundary
+in |bchar|. We set |j:=0| if |hu[0]| is to be part of the reconstruction;
+otherwise |j:=1|.
+The variable |s| will point to the tail of the current hlist, and
+|q| will point to the node following |hb|, so that
+things can be hooked up after we reconstitute the hyphenated word.
+
+@<Replace nodes |ha..hb| by a sequence of nodes...@>=
+q:=link(hb); link(hb):=null; r:=link(ha); link(ha):=null; bchar:=non_char;
+if type(hb)=ligature_node then if odd(subtype(hb)) then
+  bchar:=font_bchar[hf];
+if is_char_node(ha) then
+  begin init_list:=ha; init_lig:=false; hu[0]:=qo(character(ha));
+  end
+else if type(ha)=ligature_node then
+  begin init_list:=lig_ptr(ha); init_lig:=true; init_lft:=(subtype(ha)>1);
+  hu[0]:=qo(character(lig_char(ha)));
+  if init_list=null then if init_lft then
+    begin hu[0]:=256; init_lig:=false;
+    end; {in this case a ligature will be reconstructed from scratch}
+  free_node(ha,small_node_size);
+  end
+else goto not_found+1; {no punctuation found}
+s:=cur_p; {we have |cur_p<>ha| because |type(cur_p)=glue_node|}
+while link(s)<>ha do s:=link(s);
+j:=0; goto common_ending;
+not_found+1: j:=1; s:=ha; init_list:=null;
+if not is_char_node(r) then if type(r)=ligature_node then
+ if subtype(r)>1 then
+  begin j:=0; hu[0]:=256; init_lig:=false;
+  end;
+common_ending: flush_node_list(r);
+@<Reconstitute nodes for the hyphenated word, inserting discretionary hyphens@>;
+flush_list(init_list)
+@z
+@x modules 905--911 are entirely replaced
+@y by the following new code:
+Still further complications arise in the presence of ligatures that do not
+delete the original characters. When punctuation precedes the word being
+hyphenated, \TeX's method is not perfect under all possible scenarios,
+because punctuation marks and letters can propagate information back and forth.
+For example, suppose the original pre-hyphenation pair
+\.{*a} changes to \.{*y} via a \.{\?=:} ligature, which changes to \.{xy}
+via a \.{=:\?} ligature; if $p_{a-1}=\.x$ and $p_a=\.y$, the reconstitution
+procedure isn't smart enough to obtain \.{xy} again. In such cases the
+font designer should include a ligature that goes from \.{xa} to \.{xy}.
+
+@ The processing is facilitated by a subroutine called |reconstitute|. Given
+a string of characters $x_j\ldots x_n$, there is a smallest index $m\ge j$
+such that the ``translation'' of $x_j\ldots x_n$ by ligatures and kerning
+has the form $y_1\ldots y_t$ followed by the translation of $x_{m+1}\ldots x_n$,
+where $y_1\ldots y_t$ is some nonempty sequence of character, ligature, and
+kern nodes. We call $x_j\ldots x_m$ a ``cut prefix'' of $x_j\ldots x_n$.
+For example, if $x_1x_2x_3=\.{fly}$, and if the font contains `fl' as a
+ligature and a kern between `fl' and `y', then $m=2$, $y=2$, and $y_1$ will
+be a ligature node for `fl' followed by an appropriate kern node~$y_2$.
+In the most common case, $x_j$~forms no ligature with $x_{j+1}$ and we
+simply have $m=j$, $y_1=x_j$. If $m<n$ we can repeat the procedure on
+$x_{m+1}\ldots x_n$ until the entire translation has been found.
+
+The |reconstitute| function returns the integer $m$ and puts the nodes
+$y_1\ldots y_t$ into a linked list starting at |link(hold_head)|,
+getting the input $x_j\ldots x_n$ from the |hu| array. If $x_j=256$,
+we consider $x_j$ to be an implicit left boundary character; in this
+case |j| must be strictly less than~|n|. There is a
+parameter |bchar|, which is either 256 or an implicit right boundary character
+assumed to be present just following~$x_n$. (The value |hu[n+1]| is never
+explicitly examined, but the algorithm imagines that |bchar| is there.)
+
+If there exists an index |k| in the range $j\le k\le m$ such that |hyf[k]|
+is odd and such that the result of reconstitute would have been different
+if $x_{k+1}$ had been |hchar|, then |reconstitute| sets |hyphen_passed|
+to the smallest such~|k|. Otherwise it sets |hyphen_passed| to zero.
+
+A special convention is used in the case |j=0|: Then we assume that the
+translation of |hu[0]| appears in a special list of charnodes starting at
+|init_list|; moreover, if |init_lig| is |true|, then |hu[0]| will be
+a ligature character, involving a left boundary if |init_lft| is |true|.
+This facility is provided for cases when a hyphenated
+word is preceded by punctuation (like single or double quotes) that might
+affect the translation of the beginning of the word.
+
+@<Glob...@>=
+@!hyphen_passed:small_number; {first hyphen in a ligature, if any}
+
+@ @<Declare the function called |reconstitute|@>=
+function reconstitute(@!j,@!n:small_number;@!bchar,@!hchar:halfword):
+  small_number;
+label continue,done;
+var @!p:pointer; {temporary register for list manipulation} 
+@!t:pointer; {a node being appended to}
+@!q:four_quarters; {character information or a lig/kern instruction}
+@!cur_rh:halfword; {hyphen character for ligature testing}
+@!test_char:halfword; {hyphen or other character for ligature testing}
+@!w:scaled; {amount of kerning}
+@!k:font_index; {position of current lig/kern instruction}
+begin hyphen_passed:=0; t:=hold_head; w:=0; link(hold_head):=null;
+ {at this point |ligature_present=lft_hit=rt_hit=false|}
+@<Set up data structures with the cursor following position |j|@>;
+continue:@<If there's a ligature or kern at the cursor position, update the data
+  structures, possibly advancing~|j|; continue until the cursor moves@>;
+@<Append a ligature and/or kern to the translation;
+  |goto continue| if the stack of inserted ligatures is nonempty@>;
+reconstitute:=j;
+end;
+
+@ The reconstitution procedure shares many of the global data structures
+by which \TeX\ has processed the words before they were hyphenated.
+There is an implied ``cursor'' between characters |cur_l| and |cur_r|;
+these characters will be tested for possible ligature activity. If
+|ligature_present| then |cur_l| is a ligature character formed from the
+original characters following |cur_q| in the current translation list.
+There is a ``ligature stack'' between the cursor and character |j+1|,
+consisting of pseudo-ligature nodes linked together by their |link| fields.
+This stack is normally empty unless a ligature command has created a new
+character that will need to be processed later. A pseudo-ligature is
+a special node having a |character| field that represents a potential
+ligature and a |lig_ptr| field that points to a |char_node| or is |null|.
+We have
+$$|cur_r|=\cases{|character(lig_stack)|,&if |lig_stack>null|;\cr
+  |qi(hu[j+1])|,&if |lig_stack=null| and |j<n|;\cr
+  bchar,&if |lig_stack=null| and |j=n|.\cr}$$
+
+@<Glob...@>=
+@!cur_l,@!cur_r:halfword; {characters before and after the cursor}
+@!cur_q:pointer; {where a ligature should be detached}
+@!lig_stack:pointer; {unfinished business to the right of the cursor}
+@!ligature_present:boolean; {should a ligature node be made for |cur_l|?}
+@!lft_hit,@!rt_hit:boolean; {did we hit a ligature with a boundary character?}
+
+@ @d append_charnode_to_t(#)== begin link(t):=get_avail; t:=link(t);
+    font(t):=hf; character(t):=#;
+    end
+@d set_cur_r==begin if j<n then cur_r:=qi(hu[j+1])@+else cur_r:=bchar;
+    if odd(hyf[j]) then cur_rh:=hchar@+else cur_rh:=non_char;
+    end
+
+@<Set up data structures with the cursor following position |j|@>=
+cur_l:=qi(hu[j]); cur_q:=t;
+if j=0 then
+  begin ligature_present:=init_lig; p:=init_list;
+  if ligature_present then lft_hit:=init_lft;
+  while p>null do
+    begin append_charnode_to_t(character(p)); p:=link(p);
+    end;
+  end
+else if cur_l<non_char then append_charnode_to_t(cur_l);
+lig_stack:=null; set_cur_r
+
+@ We may want to look at the lig/kern program twice, once for a hyphen
+and once for a normal letter. (The hyphen might appear after the letter
+in the program, so we'd better not try to look for both at once.)
+
+@<If there's a ligature or kern at the cursor position, update...@>=
+if cur_l=non_char then
+  begin k:=bchar_label[hf];
+  if k=non_address then goto done@+else q:=font_info[k].qqqq;
+  end
+else begin q:=char_info(hf)(cur_l);
+  if char_tag(q)<>lig_tag then goto done;
+  k:=lig_kern_start(hf)(q); q:=font_info[k].qqqq;
+  if skip_byte(q)>stop_flag then
+    begin k:=lig_kern_restart(hf)(q); q:=font_info[k].qqqq;
+    end;
+  end; {now |k| is the starting address of the lig/kern program}
+if cur_rh<non_char then test_char:=cur_rh@+else test_char:=cur_r;
+loop@+begin if next_char(q)=test_char then if skip_byte(q)<=stop_flag then
+    if cur_rh<non_char then
+      begin hyphen_passed:=j; hchar:=non_char; cur_rh:=non_char;
+      goto continue;
+      end
+    else begin if hchar<non_char then if odd(hyf[j]) then
+        begin hyphen_passed:=j; hchar:=non_char;
+        end;
+      if op_byte(q)<kern_flag then
+      @<Carry out a ligature replacement, updating the cursor structure
+        and possibly advancing~|j|; |goto continue| if the cursor doesn't
+        advance, otherwise |goto done|@>;
+      w:=char_kern(hf)(q); goto done; {this kern will be inserted below}
+     end;
+  if skip_byte(q)>=stop_flag then
+    if cur_rh=non_char then goto done
+    else begin cur_rh:=non_char; goto continue;
+      end;
+  k:=k+qo(skip_byte(q))+1; q:=font_info[k].qqqq;
+  end;
+done:
+
+@ @d wrap_lig(#)==if ligature_present then
+    begin p:=new_ligature(hf,cur_l,link(cur_q));
+    if lft_hit then
+      begin subtype(p):=2; lft_hit:=false;
+      end;
+    if # then if lig_stack=null then
+      begin incr(subtype(p)); rt_hit:=false;
+      end;
+    link(cur_q):=p; t:=p; ligature_present:=false;
+    end
+@d pop_lig_stack==begin if lig_ptr(lig_stack)>null then
+    begin link(t):=lig_ptr(lig_stack); {this is a charnode for |hu[j+1]|}
+    t:=link(t); incr(j);
+    end;
+  p:=lig_stack; lig_stack:=link(p); free_node(p,small_node_size);
+  if lig_stack=null then set_cur_r@+else cur_r:=character(lig_stack);
+  end {if |lig_stack| isn't |null| we have |cur_rh=non_char|}
+
+@<Append a ligature and/or kern to the translation...@>=
+wrap_lig(rt_hit);
+if w<>0 then
+  begin link(t):=new_kern(w); t:=link(t); w:=0;
+  end;
+if lig_stack>null then
+  begin cur_q:=t; cur_l:=character(lig_stack); ligature_present:=true;
+  pop_lig_stack; goto continue;
+  end
+
+@ @<Carry out a ligature replacement, updating the cursor structure...@>=
+begin if cur_l=non_char then lft_hit:=true;
+if j=n then if lig_stack=null then rt_hit:=true;
+check_interrupt; {allow a way out in case there's an infinite ligature loop}
+case op_byte(q) of
+qi(1),qi(5):begin cur_l:=rem_byte(q); {\.{=:\?}, \.{=:\?>}}
+  ligature_present:=true;
+  end;
+qi(2),qi(6):begin cur_r:=rem_byte(q); {\.{\?=:}. \.{\?=:>}}
+  if lig_stack>null then character(lig_stack):=cur_r
+  else begin lig_stack:=new_lig_item(cur_r);
+    if j=n then bchar:=non_char
+    else begin p:=get_avail; lig_ptr(lig_stack):=p;
+      character(p):=qi(hu[j+1]); font(p):=hf;
+      end;
+    end;
+  end;
+qi(3):begin cur_r:=rem_byte(q); {\.{\?=:\?}}
+  p:=lig_stack; lig_stack:=new_lig_item(cur_r); link(lig_stack):=p;
+  end;
+qi(7),qi(11):begin wrap_lig(false); {\.{\?=:\?>}, \.{\?=:\?>>}}
+  cur_q:=t; cur_l:=rem_byte(q); ligature_present:=true;
+  end;
+othercases begin cur_l:=rem_byte(q); ligature_present:=true; {\.{=:}}
+  if lig_stack>null then pop_lig_stack
+  else if j=n then goto done
+  else begin append_charnode_to_t(cur_r); incr(j); set_cur_r;
+    end;
+  end
+endcases;
+if op_byte(q)>qi(4) then if op_byte(q)<>qi(7) then goto done;
+goto continue;
+end
+@z
+@x module 912
+@!c:ASCII_code; {character temporarily replaced by a hyphen}
+@y
+@!c:ASCII_code; {character temporarily replaced by a hyphen}
+@!c_loc:0..63; {where that character came from}
+@!r_count:integer; {replacement count for discretionary}
+@z
+@x modules 913--918 are to be completely replaced
+@y by the following code:
+@ When the following code is performed, |hyf[0]| and |hyf[hn]| will be zero.
+
+@<Reconstitute nodes for the hyphenated word...@>=
+repeat l:=j; j:=reconstitute(j,hn,bchar,qi(hyf_char))+1;
+if hyphen_passed=0 then
+  begin link(s):=link(hold_head);
+  while link(s)>null do s:=link(s);
+  if odd(hyf[j-1]) then
+    begin l:=j; hyphen_passed:=j-1; link(hold_head):=null;
+    end;
+  end;
+if hyphen_passed>0 then
+  @<Create and append a discretionary node as an alternative to the
+    unhyphenated word, and continue to develop both branches until they
+    become equivalent@>;
+until j>hn;
+link(s):=q
+
+@ @d advance_major_tail==begin major_tail:=link(major_tail); incr(r_count);
+    end
+
+@<Create and append a discretionary node as an alternative...@>=
+begin r:=get_node(small_node_size);
+link(r):=link(hold_head); type(r):=disc_node;
+major_tail:=r; r_count:=0;
+while link(major_tail)>null do advance_major_tail;
+i:=hyphen_passed;
+@<Put the \(c)characters |hu[l..i]| and a hyphen into |pre_break(r)|@>;
+@<Put the \(c)characters |hu[i+1..@,]| into |post_break(r)|, appending to this
+  list and to |major_tail| until synchronization has been achieved@>;
+@<Move pointer |s| to the end of the current list, and set |replace_count(r)|
+  appropriately@>;
+end
+
+@ The new hyphen might combine with the previous character via ligature
+or kern. At this point we have |l-1<=i<=j| and |i<hn|.
+
+@<Put the \(c)characters |hu[l..i]| and a hyphen into |pre_break(r)|@>=
+minor_tail:=null; pre_break(r):=null; hyf_node:=new_character(hf,hyf_char);
+if hyf_node<>null then
+  begin incr(i); c:=hu[i]; hu[i]:=hyf_char; free_avail(hyf_node);
+  end;
+while l<=i do
+  begin l:=reconstitute(l,i,font_bchar[hf],non_char)+1;
+  if link(hold_head)>null then
+    begin if minor_tail=null then pre_break(r):=link(hold_head)
+    else link(minor_tail):=link(hold_head);
+    minor_tail:=link(hold_head);
+    while link(minor_tail)>null do minor_tail:=link(minor_tail);
+    end;
+  end;
+if hyf_node<>null then
+  begin hu[i]:=c; {restore the character in the hyphen position}
+  l:=i; decr(i);
+  end
+
+@ The synchronization algorithm begins with |l=i+1<=j|.
+
+@<Put the \(c)characters |hu[i+1..@,]| into |post_break(r)|...@>=
+minor_tail:=null; post_break(r):=null; c_loc:=0;
+if bchar_label[hf]<non_address then {put left boundary at beginning of new line}
+  begin decr(l); c:=hu[l]; c_loc:=l; hu[l]:=256;
+  end;
+while l<j do
+  begin repeat l:=reconstitute(l,hn,bchar,non_char)+1;
+  if c_loc>0 then
+    begin hu[c_loc]:=c; c_loc:=0;
+    end;
+  if link(hold_head)>null then
+    begin if minor_tail=null then post_break(r):=link(hold_head)
+    else link(minor_tail):=link(hold_head);
+    minor_tail:=link(hold_head);
+    while link(minor_tail)>null do minor_tail:=link(minor_tail);
+    end;
+  until l>=j;
+  while l>j do
+    @<Append characters of |hu[j..@,]| to |major_tail|, advancing~|j|@>;
+  end
+
+@ @<Append characters of |hu[j..@,]|...@>=
+begin j:=reconstitute(j,hn,bchar,non_char)+1;
+link(major_tail):=link(hold_head);
+while link(major_tail)>null do advance_major_tail;
+end
+
+@ Ligature insertion can cause a word to grow exponentially in size. Therefore
+we must test the size of |r_count| here, even though the hyphenated text
+was at most 63 characters long.
+
+@<Move pointer |s| to the end of the current list...@>=
+if r_count>127 then {we have to forget the discretionary hyphen}
+  begin link(s):=link(r); link(r):=null; flush_node_list(r);
+  end
+else begin link(s):=r; replace_count(r):=r_count;
+  end;
+s:=major_tail
+@z
+@x module 1030
+@d main_loop=70 {go here to typeset |cur_chr| in the current font}
+@d main_loop_1=71 {like |main_loop|, but |(f,c)| = current font and char}
+@d main_loop_2=72 {like |main_loop_1|, but |c| is known to be in range}
+@d main_loop_3=73 {like |main_loop_2|, but several variables are set up}
+@d append_normal_space=74 {go here to append a normal space between words}
+@y
+@d main_loop=70 {go here to typeset a string of consecutive characters}
+@d main_loop_wrapup=80 {go here to finish a character or ligature}
+@d main_loop_move=90 {go here to advance the ligature cursor}
+@d main_loop_move_lig=95 {same, when advancing past a generated ligature}
+@d main_loop_lookahead=100 {go here to bring in another character, if any}
+@d main_lig_loop=110 {go here to check for ligatures or kerning}
+@d append_normal_space=120 {go here to append a normal space between words}
+@z
+@x ibid
+label big_switch,reswitch,main_loop,main_loop_1,main_loop_2,main_loop_3,
+@y
+label big_switch,reswitch,main_loop,main_loop_wrapup,
+  main_loop_move,main_loop_move+1,main_loop_move+2,main_loop_move_lig,
+  main_loop_lookahead,main_loop_lookahead+1,
+  main_lig_loop,main_lig_loop+1,main_lig_loop+2,
+@z
+@x ibid
+@<Local variables for the inner loop of |main_control|@>@;
+@y
+@z
+@x ibid
+hmode+char_num: begin scan_char_num; cur_chr:=cur_val; goto main_loop;
+  end;
+@y
+hmode+char_num: begin scan_char_num; cur_chr:=cur_val; goto main_loop;@+end;
+hmode+no_boundary: begin get_x_token;
+  if (cur_cmd=letter)or(cur_cmd=other_char)or(cur_cmd=char_given)or
+   (cur_cmd=char_num) then cancel_boundary:=true;
+  goto reswitch;
+  end;
+@z
+@x modules 1032--1040 are all to be replaced
+@y by the following code:
+@ The following part of the program was first written in a structured
+manner, according to the philosophy that ``premature optimization is
+the root of all evil.'' Then it was rearranged into pieces of
+spaghetti so that the most common actions could proceed with little or
+no redundancy.
+
+The original unoptimized form of this algorithm resembles the
+|reconstitute| procedure, which was described earlier in connection with
+hyphenation. Again we have an implied ``cursor`` between characters
+|cur_l| and |cur_r|. The main difference is that the |lig_stack| can now
+contain a charnode as well as pseudo-ligatures; that stack is now
+usually nonempty, because the next character of input (if any) has been
+appended to it. In |main_control| we have
+$$|cur_r|=\cases{|character(lig_stack)|,&if |lig_stack>null|;\cr
+  |font_bchar[cur_font]|,&otherwise.\cr}$$
+Several additional global variables are needed.
+
+@<Glob...@>=
+@!main_f:internal_font_number; {the current font}
+@!main_i:four_quarters; {character information bytes for |cur_l|}
+@!main_j:four_quarters; {ligature/kern command}
+@!main_k:font_index; {index into |font_info|}
+@!main_p:pointer; {temporary register for list manipulation}
+@!main_s:integer; {space factor value}
+@!bchar:halfword; {right boundary character of current font, or |non_char|}
+@!false_bchar:halfword; {nonexistent character matching |bchar|, or |non_char|}
+@!cancel_boundary:boolean; {should the left boundary be ignored?}
+@!ins_disc:boolean; {should we insert a discretionary node?}
+
+@ The boolean variables of the main loop are normally false, and always reset
+to false before the loop is left. That saves us the extra work of initializing
+each time.
+
+@<Set init...@>=
+ligature_present:=false; cancel_boundary:=false; lft_hit:=false; rt_hit:=false;
+ins_disc:=false;
+
+@ We leave |space_factor| unchanged if |sf_code(cur_chr)=0|; otherwise we
+set it to |sf_code(cur_chr)|, except that the space factor never changes
+from a value less than 1000 to a value exceeding 1000. The most common
+case is |sf_code(cur_chr)=1000|, so we want that case to be fast.
+
+The overall structure of the main loop is presented here. Some program labels
+are inside the individual sections.
+
+@d adjust_space_factor==@t@>@;@/
+  main_s:=sf_code(cur_chr);
+  if main_s=1000 then space_factor:=1000
+  else if main_s<1000 then
+    begin if main_s>0 then space_factor:=main_s;
+    end
+  else if space_factor<1000 then space_factor:=1000
+  else space_factor:=main_s
+
+@<Append character |cur_chr|...@>=
+adjust_space_factor;@/
+main_f:=cur_font;
+bchar:=font_bchar[main_f]; false_bchar:=font_false_bchar[main_f];
+if mode>0 then if language<>clang then fix_language;
+fast_get_avail(lig_stack); font(lig_stack):=main_f; cur_l:=qi(cur_chr);
+character(lig_stack):=cur_l;@/
+cur_q:=tail;
+if cancel_boundary then
+  begin cancel_boundary:=false; main_k:=non_address;
+  end
+else main_k:=bchar_label[main_f];
+if main_k=non_address then goto main_loop_move+2; {no left boundary processing}
+cur_r:=cur_l; cur_l:=non_char;
+goto main_lig_loop+1; {begin with cursor after left boundary}
+@#
+main_loop_wrapup:@<Make a ligature node, if |ligature_present|;
+  insert a null discretionary, if appropriate@>;
+main_loop_move:@<If the cursor is immediately followed by the right boundary,
+  |goto reswitch|; if it's followed by an invalid character, |goto big_switch|;
+  otherwise move the cursor one step to the right and |goto main_lig_loop|@>;
+main_loop_lookahead:@<Look ahead for another character, or leave |lig_stack|
+  empty if there's none there@>;
+main_lig_loop:@<If there's a ligature/kern command relevant to |cur_l| and
+  |cur_r|, adjust the text appropriately; exit to |main_loop_wrapup|@>;
+main_loop_move_lig:@<Move the cursor past a pseudo-ligature, then
+  |goto main_loop_lookahead| or |main_lig_loop|@>
+
+@ If the current horizontal list is empty, the reference to |character(tail)|
+here is not strictly legal, since |tail| will be a node freshly returned by
+|get_avail|. But this should cause no problem on most implementations, and we
+do want the inner loop to be fast.
+@^dirty Pascal@>
+
+A discretionary break is not inserted for an explicit hyphen when we are in
+restricted horizontal mode. In particular, this avoids putting discretionary
+nodes inside of other discretionaries.
+
+@d pack_lig(#)== {the parameter is either |rt_hit| or |false|}
+  begin main_p:=new_ligature(main_f,cur_l,link(cur_q));
+  if lft_hit then
+    begin subtype(main_p):=2; lft_hit:=false;
+    end;
+  if # then if lig_stack=null then
+    begin incr(subtype(main_p)); rt_hit:=false;
+    end;
+  link(cur_q):=main_p; tail:=main_p; ligature_present:=false;
+  end
+
+@d wrapup(#)==if cur_l<non_char then
+  begin if character(tail)=qi(hyphen_char[main_f]) then if link(cur_q)>null then
+    ins_disc:=true;
+  if ligature_present then pack_lig(#);
+  if ins_disc then
+    begin ins_disc:=false;
+    if mode>0 then tail_append(new_disc);
+    end;
+  end
+
+@<Make a ligature node, if |ligature_present|;...@>=
+wrapup(rt_hit)
+
+@ @<If the cursor is immediately followed by the right boundary...@>=
+if lig_stack=null then goto reswitch;
+cur_q:=tail; cur_l:=cur_r; {or |character(lig_stack)|}
+main_loop_move+1:if not is_char_node(lig_stack) then goto main_loop_move_lig;
+main_loop_move+2:if(cur_chr<font_bc[main_f])or(cur_chr>font_ec[main_f]) then
+  begin char_warning(main_f,cur_chr); free_avail(lig_stack); goto big_switch;
+  end;
+main_i:=char_info(main_f)(cur_l);
+if not char_exists(main_i) then
+  begin char_warning(main_f,cur_chr); free_avail(lig_stack); goto big_switch;
+  end;
+tail_append(lig_stack) {|main_loop_lookahead| is next}
+
+@ Here we are at |main_loop_move_lig|.
+When we begin this code we have |cur_l=character(lig_stack)| and |cur_q=tail|.
+
+@<Move the cursor past a pseudo-ligature...@>=
+main_p:=lig_ptr(lig_stack);
+if main_p>null then tail_append(main_p);
+temp_ptr:=lig_stack; lig_stack:=link(temp_ptr);
+free_node(temp_ptr,small_node_size);
+main_i:=char_info(main_f)(cur_l); ligature_present:=true;
+if lig_stack=null then
+  if main_p>null then goto main_loop_lookahead
+  else cur_r:=bchar
+else cur_r:=character(lig_stack);
+goto main_lig_loop
+
+@ The result of \.{\\char} can participate in a ligature or kern, so we must
+look ahead for it.
+
+@<Look ahead for another character...@>=
+get_next; {set only |cur_cmd| and |cur_chr|, for speed}
+if cur_cmd=letter then goto main_loop_lookahead+1;
+if cur_cmd=other_char then goto main_loop_lookahead+1;
+if cur_cmd=char_given then goto main_loop_lookahead+1;
+x_token; {now expand and set |cur_cmd|, |cur_chr|, |cur_tok|}
+if cur_cmd=letter then goto main_loop_lookahead+1;
+if cur_cmd=other_char then goto main_loop_lookahead+1;
+if cur_cmd=char_given then goto main_loop_lookahead+1;
+if cur_cmd=char_num then
+  begin scan_char_num; cur_chr:=cur_val; goto main_loop_lookahead+1;
+  end;
+if cur_cmd=no_boundary then bchar:=non_char;
+cur_r:=bchar; lig_stack:=null; goto main_lig_loop;
+main_loop_lookahead+1: adjust_space_factor;
+fast_get_avail(lig_stack); font(lig_stack):=main_f;
+cur_r:=qi(cur_chr); character(lig_stack):=cur_r;
+if cur_r=false_bchar then cur_r:=non_char {this prevents spurious ligatures}
+
+@ Even though comparatively few characters have a lig/kern program, several
+of the instructions here count as part of \TeX's inner loop, since a
+potentially long sequential search must be performed. For example, tests with
+Computer Modern Roman showed that about 40 per cent of all characters
+actually encountered in practice had a lig/kern program, and that about four
+lig/kern commands were investigated for every such character.
+
+At the beginning of this code we have |main_i=char_info(main_f)(cur_l)|.
+
+@<If there's a ligature/kern command...@>=
+if char_tag(main_i)<>lig_tag then goto main_loop_wrapup;
+main_k:=lig_kern_start(main_f)(main_i); main_j:=font_info[main_k].qqqq;
+if skip_byte(main_j)<=stop_flag then goto main_lig_loop+2;
+main_k:=lig_kern_restart(main_f)(main_j);
+main_lig_loop+1:main_j:=font_info[main_k].qqqq;
+main_lig_loop+2:if next_char(main_j)=cur_r then
+ if skip_byte(main_j)<=stop_flag then
+  @<Do ligature or kern command, returning to |main_lig_loop|
+  or |main_loop_wrapup| or |main_loop_move|@>;
+if skip_byte(main_j)=qi(0) then incr(main_k)
+else begin if skip_byte(main_j)>=stop_flag then goto main_loop_wrapup;
+  main_k:=main_k+qo(skip_byte(main_j))+1;
+  end;
+goto main_lig_loop+1
+
+@ When a ligature or kern instruction matches a character, we know from
+|read_font_info| that the character exists in the font, even though we
+haven't verified its existence in the normal way.
+
+This section could be made into a subroutine, if the code inside
+|main_control| needs to be shortened.
+
+\chardef\?='174 % vertical line to indicate character retention
+
+@<Do ligature or kern command...@>=
+begin if op_byte(main_j)>=kern_flag then
+  begin wrapup(rt_hit);
+  tail_append(new_kern(char_kern(main_f)(main_j))); goto main_loop_move;
+  end;
+if cur_l=non_char then lft_hit:=true
+else if lig_stack=null then rt_hit:=true;
+check_interrupt; {allow a way out in case there's an infinite ligature loop}
+case op_byte(main_j) of
+qi(1),qi(5):begin cur_l:=rem_byte(main_j); {\.{=:\?}, \.{=:\?>}}
+  main_i:=char_info(main_f)(cur_l); ligature_present:=true;
+  end;
+qi(2),qi(6):begin cur_r:=rem_byte(main_j); {\.{\?=:}, \.{\?=:>}}
+  if lig_stack=null then {right boundary character is being consumed}
+    begin lig_stack:=new_lig_item(cur_r); bchar:=non_char;
+    end
+  else if is_char_node(lig_stack) then {|link(lig_stack)=null|}
+    begin main_p:=lig_stack; lig_stack:=new_lig_item(cur_r);
+    lig_ptr(lig_stack):=main_p;
+    end
+  else character(lig_stack):=cur_r;
+  end;
+qi(3):begin cur_r:=rem_byte(main_j); {\.{\?=:\?}}
+  main_p:=lig_stack; lig_stack:=new_lig_item(cur_r);
+  link(lig_stack):=main_p;
+  end;
+qi(7),qi(11):begin wrapup(false); {\.{\?=:\?>}, \.{\?=:\?>>}}
+  cur_q:=tail; cur_l:=rem_byte(main_j);
+  main_i:=char_info(main_f)(cur_l); ligature_present:=true;
+  end;
+othercases begin cur_l:=rem_byte(main_j); ligature_present:=true; {\.{=:}}
+  if lig_stack=null then goto main_loop_wrapup
+  else goto main_loop_move+1;
+  end
+endcases;
+if op_byte(main_j)>qi(4) then
+  if op_byte(main_j)<>qi(7) then goto main_loop_wrapup;
+if cur_l<non_char then goto main_lig_loop;
+main_k:=bchar_label[main_f]; goto main_lig_loop+1;
+end
+@z
+% HINTS for making main_control shorter if you need to conserve space:
+% (1) make pack_lig(#) a procedure call instead of a macro call
+% (2) make the code of @<Do ligature...@> a function that returns one of
+%     four values; you goto a label based on the value returned.
+@x module 1042
+begin p:=font_glue[cur_font];
+if p=null then
+  begin f:=cur_font; p:=new_spec(zero_glue); k:=param_base[f]+space_code;
+  width(p):=font_info[k].sc; {that's |space(f)|}
+  stretch(p):=font_info[k+1].sc; {and |space_stretch(f)|}
+  shrink(p):=font_info[k+2].sc; {and |space_shrink(f)|}
+  font_glue[f]:=p;
+@y
+begin main_p:=font_glue[cur_font];
+if main_p=null then
+  begin main_p:=new_spec(zero_glue); main_k:=param_base[cur_font]+space_code;
+  width(main_p):=font_info[main_k].sc; {that's |space(cur_font)|}
+  stretch(main_p):=font_info[main_k+1].sc; {and |space_stretch(cur_font)|}
+  shrink(main_p):=font_info[main_k+2].sc; {and |space_shrink(cur_font)|}
+  font_glue[cur_font]:=main_p;
+@z
+@x module 1045
+any_mode(relax),vmode+spacer,mmode+spacer,mmode+no_boundary:do_nothing;
+@y
+any_mode(relax),vmode+spacer,mmode+spacer:do_nothing;
+@z
+@x module 1090
+   vmode+ex_space:@t@>@;@/
+@y
+   vmode+ex_space,vmode+no_boundary:@t@>@;@/
+@z
+@x module 1322
+dump_int(font_glue[k]);@/
+@y
+dump_int(font_glue[k]);@/
+dump_int(bchar_label[k]);
+dump_int(font_bchar[k]);
+dump_int(font_false_bchar[k]);@/
+@z
+@x module 1323
+undump(min_halfword)(lo_mem_max)(font_glue[k]);@/
+@y
+undump(min_halfword)(lo_mem_max)(font_glue[k]);@/
+undump(0)(font_mem_size)(bchar_label[k]);
+undump(min_quarterword)(non_char)(font_bchar[k]);
+undump(min_quarterword)(non_char)(font_false_bchar[k]);
+@z
+
+363. New \inputlineno feature desired by Spivak
+@x module 416 gets a new definition and a new statement
+@y
+@d input_line_no_code=glue_val+1 {code for \.{\\inputlineno}}
+primitive("inputlineno",last_item,input_line_no_code);
+@!@:input_line_no_}{\.{\\inputlineno} primitive@>
+@z and module 417 changes in the obvious way
+@x module 424 gets new code at the beginning
+@y
+if cur_chr>glue_val then
+  begin cur_val:=line; cur_val_level:=int_val;
+  end
+else
+@z
+
+364. New feature \holdinginserts suggested by Mittelbach.
+@x modules 236--238 get a new integer parameter
+@d int_pars=53 {total number of integer parameters}
+@y
+@d holding_inserts_code=53 {do not remove insertion nodes from \.{\\box255}}
+@d int_pars=54 {total number of integer parameters}
+@z and appropriate further lines are added to match all the other parameters
+@x module 1014
+@<Prepare all the boxes involved in insertions to act as queues@>;
+q:=hold_head; link(q):=null; prev_p:=page_head; p:=link(prev_p);
+while p<>best_page_break do
+  begin if type(p)=ins_node then @<Either insert the material
+    specified by node |p| into the appropriate box, or
+    hold it for the next page; also delete node |p| from
+    the current page@>
+@y
+if holding_inserts<=0 then
+  @<Prepare all the boxes involved in insertions to act as queues@>;
+q:=hold_head; link(q):=null; prev_p:=page_head; p:=link(prev_p);
+while p<>best_page_break do
+  begin if type(p)=ins_node then
+    begin if holding_inserts<=0 then
+       @<Either insert the material specified by node |p| into the
+         appropriate box, or hold it for the next page;
+         also delete node |p| from the current page@>;
+    end
+@z
+% also insert begin...end around the Pascal code of module 1018
+
+365. New \badness feature (which I'd been resisting for years)
+@x module 416 gets a new definition and a new statement
+@y
+@d badness_code=glue_val+2 {code for \.{\\badness}}
+primitive("badness",last_item,badness_code);
+@!@:badness_}{\.{\\badness} primitive@>
+@z and module 417 changes in the obvious way
+@x module 424 (the new code just added in #363)
+  begin cur_val:=line; cur_val_level:=int_val;
+@y
+  begin if cur_chr=input_line_no_code then cur_val:=line
+  else cur_val:=last_badness; {|cur_chr=badness_code|}
+  cur_val_level:=int_val;
+@z
+@x module 646 gets a new global variable
+@y
+@!last_badness:integer; {badness of the most recently packaged box}
+@z
+@x module 648
+@ @<Set init...@>=adjust_tail:=null;
+@y
+@ @<Set init...@>=adjust_tail:=null; last_badness:=0;
+@z
+@x modules 649 and 668
+@!b:integer; {badness of the new box}
+begin r:=get_node(box_node_size); type(r):=hlist_node;
+@y (except it's vlist_node in 668)
+begin last_badness:=0; r:=get_node(box_node_size); type(r):=hlist_node;
+@z (except it's vlist_node in 668)
+% change b to last_badness in modules 660&674 (4 times), 667&678 (3 times)
+@x modules 658 and 673
+if (hbadness<inf_bad)and(o=normal)and(list_ptr(r)<>null) then
+@y (except it's vbadness in 673)
+if o=normal then if list_ptr(r)<>null then
+@z
+@x modules 664 and 676
+  begin set_glue_ratio_one(glue_set(r)); {this is the maximum shrinkage}
+@y
+  begin last_badness:=1000000;
+  set_glue_ratio_one(glue_set(r)); {use the maximum shrinkage}
+@z
+@x ibid
+else if (hbadness<100)and(o=normal)and(list_ptr(r)<>null) then
+@y (except it's vbadness in 676)
+else if o=normal then if list_ptr(r)<>null then
+@z
+
+366. New \emergencystretch feature
+@x modules 247--248 get a new dimen parameter
+@d dimen_pars=20 {total number of dimension parameters}
+@y
+@d emergency_stretch_code=20 {reduces badnesses on final pass of line-breaking}
+@d dimen_pars=21 {total number of dimension parameters}
+@z and appropriate further lines are added to match all the other parameters
+@x module 828
+@!second_pass:boolean; {is this our second attempt to break this paragraph?}
+@y
+@!second_pass:boolean; {is this our second attempt to break this paragraph?}
+@!final_pass:boolean; {is this our final attempt to break this paragraph?}
+@z
+% change second_pass to final_pass in modules 854 and 873
+@x module 863
+  second_pass:=false;
+  end
+else  begin threshold:=tolerance; second_pass:=true;
+@y
+  second_pass:=false; final_pass:=false;
+  end
+else  begin threshold:=tolerance; second_pass:=true;
+  final_pass:=(emergency_stretch<=0);
+@z
+@x ibid
+  @!stat if tracing_paragraphs>0 then print_nl("@@secondpass");@;@+tats@/
+  threshold:=tolerance; second_pass:=true; {if at first you don't
+    succeed, \dots}
+@y
+  if not second_pass then
+    begin@!stat if tracing_paragraphs>0 then print_nl("@@secondpass");@;@+tats@/
+    threshold:=tolerance; second_pass:=true; final_pass:=(emergency_stretch<=0);
+    end {if at first you don't succeed, \dots}
+  else begin @!stat if tracing_paragraphs>0 then
+      print_nl("@@finalpass");@;@+tats@/
+    background[2]:=background[2]+emergency_stretch; final_pass:=true;
+    end;
+@z
+
+367. New \errorcontextlines feature suggested by a TUG participant
+@x modules 236--238 get a new integer parameter
+@d int_pars=54 {total number of integer parameters}
+@y
+@d error_context_lines_code=54 {maximum intermediate line pairs shown}
+@d int_pars=55 {total number of integer parameters}
+@z and appropriate further lines are added to match all the other parameters
+@x module 311
+@<Local variables for formatting calculations@>@/
+begin base_ptr:=input_ptr; input_stack[base_ptr]:=cur_input;
+  {store current state}
+loop@+begin cur_input:=input_stack[base_ptr]; {enter into the context}
+  @<Display the current context@>;
+  if (state<>token_list) then
+    if (name>17) or (base_ptr=0) then goto done;
+@y
+@!nn:integer; {number of contexts shown so far, less one}
+@!bottom_line:boolean; {have we reached the final context to be shown?}
+@<Local variables for formatting calculations@>@/
+begin base_ptr:=input_ptr; input_stack[base_ptr]:=cur_input;
+  {store current state}
+nn:=-1; bottom_line:=false;
+loop@+begin cur_input:=input_stack[base_ptr]; {enter into the context}
+  if (state<>token_list) then
+    if (name>17) or (base_ptr=0) then bottom_line:=true;
+  if (base_ptr=input_ptr)or bottom_line or(nn<error_context_lines) then
+    @<Display the current context@>
+  else if nn=error_context_lines then
+    begin print_nl("..."); incr(nn); {omitted if |error_context_lines<0|}
+    end;
+  if bottom_line then goto done;
+@z
+% also insert begin...end around the Pascal code of module 312
+% and add the statement "incr(nn)" to that module
+
+368. char_warning inside hyphenation could clobber old_setting
+@x module 863
+done: @!stat if tracing_paragraphs>0 then end_diagnostic(true);@;@+tats@/
+@y
+done: @!stat if tracing_paragraphs>0 then
+  begin end_diagnostic(true); normalize_selector;
+  end;@+tats@/
+@z
+
+369. Make ".fmt" more easily switchable (Don Hosek).
+@x module 520 gets a new definition
+@y
+@d format_extension=".fmt" {the extension, as a \.{WEB} constant}
+@z now replace ".fmt" by format_extension in modules 529 and 1328.
+
+370. Possible range check on weird nullfont (Breitenlohner, 16 Oct 89).
+@x module 565
+if (bc>ec+1)or(ec>255) then abort;
+@y
+if (bc>ec+1)or(ec>255) then abort;
+if bc>255 then {|bc=256| and |ec=255|}
+  begin bc:=1; ec:=0;
+  end;
+@z
+
+371. Prevent save_stack conflicts, e.g. in {\hbox\expandafter{\csname
+     \endcsname}} (found by Sullivan).
+@x module 645
+@p procedure scan_spec; {scans a box specification and left brace}
+label found;
+begin if scan_keyword("to") then saved(0):=exactly
+@.to@>
+else if scan_keyword("spread") then saved(0):=additional
+@.spread@>
+else  begin saved(0):=additional; saved(1):=0;
+  goto found;
+  end;
+scan_normal_dimen; saved(1):=cur_val;
+found: save_ptr:=save_ptr+2; scan_left_brace;
+@y
+@p procedure scan_spec(@!c:group_code;@!three_codes:boolean);
+  {scans a box specification and left brace}
+label found;
+var @!s:integer; {temporarily saved value}
+@!spec_code:exactly..additional;
+begin if three_codes then s:=saved(0);
+if scan_keyword("to") then spec_code:=exactly
+@.to@>
+else if scan_keyword("spread") then spec_code:=additional
+@.spread@>
+else  begin spec_code:=additional; cur_val:=0;
+  goto found;
+  end;
+scan_normal_dimen;
+found: if three_codes then
+  begin saved(0):=s; incr(save_ptr);
+  end;
+saved(0):=spec_code; saved(1):=cur_val; save_ptr:=save_ptr+2;
+new_save_level(c); scan_left_brace;
+@z
+@x module 774
+scan_spec; new_save_level(align_group);@/
+@y
+scan_spec(align_group,false);@/
+@z
+@x module 1073
+  if t=0 then saved(0):=cur_val@+else saved(0):=-cur_val;
+  scan_box;
+  end;
+any_mode(leader_ship): begin saved(0):=leader_flag-a_leaders+cur_chr; scan_box;
+  end;
+any_mode(make_box): begin saved(0):=0; begin_box;
+  end;
+@y
+  if t=0 then scan_box(cur_val)@+else scan_box(-cur_val);
+  end;
+any_mode(leader_ship): scan_box(leader_flag-a_leaders+cur_chr);
+any_mode(make_box): begin_box(0);
+@z
+@x module 1075
+procedure box_end;
+var p:pointer; {|ord_noad| for new box in math mode}
+begin if saved(0)<box_flag then @<Append box |cur_box| to the current list,
+    shifted by |saved(0)|@>
+else if saved(0)<ship_out_flag then @<Store \(c)|cur_box| in a box register@>
+else if cur_box<>null then
+  if saved(0)>ship_out_flag then @<Append a new leader node that
+      uses |cur_box|@>
+@y
+procedure box_end(@!box_context:integer);
+var p:pointer; {|ord_noad| for new box in math mode}
+begin if box_context<box_flag then @<Append box |cur_box| to the current list,
+    shifted by |box_context|@>
+else if box_context<ship_out_flag then @<Store \(c)|cur_box| in a box register@>
+else if cur_box<>null then
+  if box_context>ship_out_flag then @<Append a new leader node that
+      uses |cur_box|@>
+@z
+@x module 1076
+  begin shift_amount(cur_box):=saved(0);
+@y
+  begin shift_amount(cur_box):=box_context;
+@z
+@x module 1077
+if saved(0)<box_flag+256 then
+  eq_define(box_base-box_flag+saved(0),box_ref,cur_box)
+else geq_define(box_base-box_flag-256+saved(0),box_ref,cur_box)
+@y
+if box_context<box_flag+256 then
+  eq_define(box_base-box_flag+box_context,box_ref,cur_box)
+else geq_define(box_base-box_flag-256+box_context,box_ref,cur_box)
+@z
+@x module 1078
+  begin append_glue; subtype(tail):=saved(0)-(leader_flag-a_leaders);
+@y
+  begin append_glue; subtype(tail):=box_context-(leader_flag-a_leaders);
+@z
+@x module 1079
+procedure begin_box;
+@y
+procedure begin_box(@!box_context:integer);
+@z
+@x ibid
+box_end; {in simple cases, we use the box immediately}
+@y
+box_end(box_context); {in simple cases, we use the box immediately}
+@z
+@x module 1083
+incr(save_ptr); scan_spec;
+if k=hmode then
+  if (saved(-3)<box_flag)and(abs(mode)=vmode) then
+    new_save_level(adjusted_hbox_group)
+  else new_save_level(hbox_group)
+else  begin if k=vmode then new_save_level(vbox_group)
+  else  begin new_save_level(vtop_group); k:=vmode;
+@y
+saved(0):=box_context;
+if k=hmode then
+  if (box_context<box_flag)and(abs(mode)=vmode) then
+    scan_spec(adjusted_hbox_group,true)
+  else scan_spec(hbox_group,true)
+else  begin if k=vmode then scan_spec(vbox_group,true)
+  else  begin scan_spec(vtop_group,true); k:=vmode;
+@z
+@x module 1084
+procedure scan_box; {the next input should specify a box or perhaps a rule}
+begin @<Get the next non-blank non-relax...@>;
+if cur_cmd=make_box then begin_box
+else if (saved(0)>=leader_flag)and((cur_cmd=hrule)or(cur_cmd=vrule)) then
+  begin cur_box:=scan_rule_spec; box_end;
+@y
+procedure scan_box(@!box_context:integer);
+  {the next input should specify a box or perhaps a rule}
+begin @<Get the next non-blank non-relax...@>;
+if cur_cmd=make_box then begin_box(box_context)
+else if (box_context>=leader_flag)and((cur_cmd=hrule)or(cur_cmd=vrule)) then
+  begin cur_box:=scan_rule_spec; box_end(box_context);
+@z
+@x module 1086
+pop_nest; box_end;
+@y
+pop_nest; box_end(saved(0));
+@z
+@x module 1117
+else  begin incr(save_ptr); saved(-1):=0; scan_left_brace;
+  new_save_level(disc_group); push_nest; mode:=-hmode; space_factor:=1000;
+@y
+else  begin incr(save_ptr); saved(-1):=0; new_save_level(disc_group);
+  scan_left_brace; push_nest; mode:=-hmode; space_factor:=1000;
+@z
+@x module 1119
+incr(saved(-1)); scan_left_brace; new_save_level(disc_group);
+@y
+incr(saved(-1)); new_save_level(disc_group); scan_left_brace;
+@z
+@x module 1167
+mmode+vcenter: begin scan_spec; new_save_level(vcenter_group); normal_paragraph;
+@y
+mmode+vcenter: begin scan_spec(vcenter_group,false); normal_paragraph;
+@z
+@x module 1172
+scan_left_brace; push_math(math_choice_group);
+@y
+push_math(math_choice_group); scan_left_brace;
+@z
+@x module 1174
+incr(saved(-1)); scan_left_brace; push_math(math_choice_group);
+@y
+incr(saved(-1)); push_math(math_choice_group); scan_left_brace;
+@z
+@x module 1241
+  if global then saved(0):=box_flag+256+cur_val
+  else saved(0):=box_flag+cur_val;
+  scan_optional_equals; scan_box;
+@y
+  if global then n:=256+cur_val@+else n:=cur_val;
+  scan_optional_equals; scan_box(box_flag+n);
+@z
+
+372. Bugfix 339 didn't go far enough (found by Sch\"opf and Mittelbach).
+@x module 516 [NOTE: THIS AFFECTS ALMOST ALL CHANGE FILES!]
+@ And here's the second.
+@^system dependencies@>
+
+@p function more_name(@!c:ASCII_code):boolean;
+begin if c=" " then more_name:=false
+else  begin if (c=">")or(c=":") then
+    begin area_delimiter:=pool_ptr; ext_delimiter:=0;
+    end
+  else if (c=".")and(ext_delimiter=0) then ext_delimiter:=pool_ptr;
+  str_room(1); append_char(c); {contribute |c| to the current string}
+@y
+@ And here's the second. The string pool might change as the file name is
+being scanned, since a new \.{\\csname} might be entered; therefore we keep
+|area_delimiter| and |ext_delimiter| relative to the beginning of the current
+string, instead of assigning an absolute address like |pool_ptr| to them.
+@^system dependencies@>
+
+@p function more_name(@!c:ASCII_code):boolean;
+begin if c=" " then more_name:=false
+else  begin str_room(1); append_char(c); {contribute |c| to the current string}
+  if (c=">")or(c=":") then
+    begin area_delimiter:=cur_length; ext_delimiter:=0;
+    end
+  else if (c=".")and(ext_delimiter=0) then ext_delimiter:=cur_length;
+@z
+@x module 517 [NOTE: THIS DOES TOO, AND SO DOES THE NEXT!]
+else  begin cur_area:=str_ptr; incr(str_ptr);
+  str_start[str_ptr]:=area_delimiter+1;
+@y
+else  begin cur_area:=str_ptr;
+  str_start[str_ptr+1]:=str_start[str_ptr]+area_delimiter; incr(str_ptr);
+@z
+@x ibid
+else  begin cur_name:=str_ptr; incr(str_ptr);
+  str_start[str_ptr]:=ext_delimiter; cur_ext:=make_string;
+@y
+else  begin cur_name:=str_ptr;
+  str_start[str_ptr+1]:=str_start[str_ptr]+ext_delimiter-area_delimiter-1;
+  incr(str_ptr); cur_ext:=make_string;
+@z
+
+373. Allow multiple hyphenmins in the same paragraph (Mike Ferguson).
+@x module 212, two new fields for list_state_record
+@y
+  @!lhm_field,@!rhm_field: quarterword;
+@z
+@x module 213, two new macros to access those fields
+@y
+@d lhmin==cur_list.lhm_field {\.{\\lefthyphenmin} at start of paragraph}
+@d rhmin==cur_list.rhm_field {\.{\\righthyphenmin} at start of paragraph}
+@z
+@x module 215, two new initializations
+@y
+lhmin:=0; rhmin:=0;
+@z
+@x module 218
+  if nest[p].ml_field<0 then print(" (\output routine)");
+@y
+  if m=hmode then@+if(nest[p].lhm_field<>2)or(nest[p].rhm_field<>3)then
+    begin print(" (hyphenmin "); print_int(nest[p].lhm_field); print_char(",");
+    print_int(nest[p].rhm_field); print_char(")");
+    end;
+  if nest[p].ml_field<0 then print(" (\output routine)");
+@z
+@x module 891
+l_hyf:=left_hyphen_min-1;@+if l_hyf<0 then l_hyf:=0;
+r_hyf:=right_hyphen_min-1;@+if r_hyf<0 then r_hyf:=0;
+min_hyf:=l_hyf+r_hyf+2; cur_lang:=0;
+@y
+l_hyf:=lhmin; r_hyf:=rhmin; cur_lang:=0;
+@z
+@x module 892
+@!l_hyf,@!r_hyf,@!min_hyf:integer; {limits on fragment sizes}
+@y
+@!l_hyf,@!r_hyf:integer; {limits on fragment sizes}
+@z
+@x module 894
+begin if min_hyf>63 then goto done1;
+prev_s:=cur_p; s:=link(prev_s);
+if s<>null then
+  begin @<Skip to node |ha|, or |goto done1| if no hyphenation
+    should be attempted@>;
+  @<Skip to node |hb|, putting letters into |hu| and |hc|@>;
+  @<Check that the nodes following |hb| permit hyphenation and that at least
+    |min_hyf| letters have been found, otherwise |goto done1|@>;
+@y
+begin prev_s:=cur_p; s:=link(prev_s);
+if s<>null then
+  begin @<Skip to node |ha|, or |goto done1| if no hyphenation
+    should be attempted@>;
+  if l_hyf+r_hyf>63 then goto done1;
+  @<Skip to node |hb|, putting letters into |hu| and |hc|@>;
+  @<Check that the nodes following |hb| permit hyphenation and that at least
+    |l_hyf+r_hyf| letters have been found, otherwise |goto done1|@>;
+@z
+@x module 899
+if hn<min_hyf then goto done1;
+@y
+if hn<l_hyf+r_hyf then goto done1;
+@z
+@x module 902
+for j:=l_hyf+1 to hn-r_hyf-1 do if odd(hyf[j]) then goto found1;
+@y
+for j:=l_hyf to hn-r_hyf do if odd(hyf[j]) then goto found1;
+@z
+@x module 923
+for j:=0 to hn-r_hyf do
+@y
+for j:=0 to hn-r_hyf+1 do
+@z
+@x ibid
+found: for j:=0 to l_hyf do hyf[j]:=0;
+for j:=0 to r_hyf do hyf[hn-j]:=0
+@y
+found: for j:=0 to l_hyf-1 do hyf[j]:=0;
+for j:=0 to r_hyf-1 do hyf[hn-j]:=0
+@z
+@x module 1091 begins with a new subroutine
+@y
+function norm_min(@!h:integer):small_number;
+begin if h<=0 then norm_min:=1@+else if h>=63 then norm_min:=63@+
+else norm_min:=h;
+end;
+@z
+@x module 1091 then uses the new subroutine
+push_nest; mode:=hmode; space_factor:=1000; clang:=0;
+@y
+lhmin:=norm_min(left_hyphen_min); rhmin:=norm_min(right_hyphen_min);
+push_nest; mode:=hmode; space_factor:=1000; clang:=0;
+@z
+@x module 1341
+@d stored_language(#)==mem[#+1].int {language number, in the range |0..255|}
+@y
+@d what_lang(#)==link(#+1) {language number, in the range |0..255|}
+@d what_lhm(#)==type(#+1) {minimum left fragment, in the range |1..63|}
+@d what_rhm(#)==subtype(#+1) {minimum right fragment, in the range |1..63|}
+@z
+@x module 1356
+  print_int(stored_language(p));
+@y
+  print_int(what_lang(p)); print(" (hyphenmin ");
+  print_int(what_lhm(p)); print_char(",");
+  print_int(what_rhm(p)); print_char(")");
+@z
+@x modules 1362 and 1363
+@ @<Advance \(p)past a whatsit node in the \(l)|line_break| loop@>=
+if subtype(cur_p)=language_node then cur_lang:=stored_language(cur_p)
+
+@ @<Advance \(p)past a whatsit node in the \(p)pre-hyphenation loop@>=
+if subtype(s)=language_node then cur_lang:=stored_language(s)
+@y
+@ @d adv_past(#)==@+if subtype(#)=language_node then
+    begin cur_lang:=what_lang(#); l_hyf:=what_lhm(#); r_hyf:=what_rhm(#);@+end
+
+@<Advance \(p)past a whatsit node in the \(l)|line_break| loop@>=@+
+adv_past(cur_p)
+
+@ @<Advance \(p)past a whatsit node in the \(p)pre-hyphenation loop@>=@+
+adv_past(s)
+@z
+@x module 1376
+  stored_language(tail):=l; clang:=l;
+@y
+  what_lang(tail):=l; clang:=l;@/
+  what_lhm(tail):=norm_min(left_hyphen_min);
+  what_rhm(tail):=norm_min(right_hyphen_min);
+@z
+@x module 1377
+  stored_language(tail):=clang;
+@y
+  what_lang(tail):=clang;
+  what_lhm(tail):=norm_min(left_hyphen_min);
+  what_rhm(tail):=norm_min(right_hyphen_min);
+@z
+
+374. Make \par and end_template definitely non-character (Marc van Leeuwen)
+@x module 14 gets a new line
+@y
+if mem_top<256+11 then bad:=7; {we will want |null_list>255|}
+@z
+@x module 334
+primitive("par",par_end,0); par_loc:=cur_val; par_token:=cs_token_flag+par_loc;
+@y
+primitive("par",par_end,256); {cf. |scan_file_name|}
+par_loc:=cur_val; par_token:=cs_token_flag+par_loc;
+@z
+
+375. Alignments must be more robust to prevent crashes (Marc van Leeuwen)
+@x module 324
+else if token_type=u_template then align_state:=0;
+@y
+else if token_type=u_template then
+  if align_state>500000 then align_state:=0
+  else fatal_error("(interwoven alignment preambles are not allowed)");
+@.interwoven alignment preambles...@>
+@z
+@x module 782
+if (cur_cmd=assign_glue)and(cur_chr=glue_base+tab_skip_code) then
+@y
+if cur_cmd=endv then
+  fatal_error("(interwoven alignment preambles are not allowed)");
+@.interwoven alignment preambles...@>
+if (cur_cmd=assign_glue)and(cur_chr=glue_base+tab_skip_code) then
+@z
+@x module 791
+p:=link(q);
+@y
+if align_state<500000 then
+  fatal_error("(interwoven alignment preambles are not allowed)");
+@.interwoven alignment preambles...@>
+p:=link(q);
+@z
+
+376. Avoid kern removal in discretionary breaks (Marc van Leeuwen)
+@x module 815
+label done,done1,done2,done3,done4,continue;
+@y
+label done,done1,done2,done3,done4,done5,continue;
+@z
+@x module 866
+glue_node: begin @<If node |cur_p| is a legal breakpoint, call |try_break|@>;
+  @<Update the active widths by including the glue in |glue_ptr(cur_p)|@>;
+@y
+glue_node: begin @<If node |cur_p| is a legal breakpoint, call |try_break|;
+  then update the active widths by including the glue in |glue_ptr(cur_p)|@>;
+@z
+@x ibid
+disc_node: @<Try to break after a discretionary fragment@>;
+@y
+disc_node: @<Try to break after a discretionary fragment, then |goto done5|@>;
+@z
+@x ibid
+end
+@y
+done5:end
+@z
+Combine modules 868 and 869 into a single module, with a semicolon between.
+@x module 870 (which becomes module 869) gets ... in its title
+@y and the following new code just before its final "end":
+r:=replace_count(cur_p); s:=link(cur_p);
+while r>0 do
+  begin @<Add the width of node |s| to |act_width|@>;
+  decr(r); s:=link(s);
+  end;
+prev_p:=cur_p; cur_p:=s; goto done5;
+@z
+@x Now module 871 becomes 870, and we add a new (very similar) module 871:
+@y
+@ @<Add the width of node |s| to |act_width|@>=
+if is_char_node(s) then
+  begin f:=font(s);
+  act_width:=act_width+char_width(f)(char_info(f)(character(s)));
+  end
+else  case type(s) of
+  ligature_node: begin f:=font(lig_char(s));
+    act_width:=act_width+
+      char_width(f)(char_info(f)(character(lig_char(s))));
+    end;
+  hlist_node,vlist_node,rule_node,kern_node:
+    act_width:=act_width+width(s);
+  othercases confusion("disc4")
+@:this can't happen disc4}{\quad disc4@>
+  endcases
+@z
+@x module 877
+@!disc_break:boolean; {was the current break at a discretionary node?}
+@y
+@!disc_break:boolean; {was the current break at a discretionary node?}
+@!post_disc_break:boolean; {and did it have a nonempty post-break part?}
+@z
+@x ibid
+if cur_p<>null then @<Prune unwanted nodes at the beginning of the next line@>;
+@y
+if cur_p<>null then if not post_disc_break then
+  @<Prune unwanted nodes at the beginning of the next line@>;
+@z
+@x module 881
+q:=cur_break(cur_p); disc_break:=false;
+@y
+q:=cur_break(cur_p); disc_break:=false; post_disc_break:=false;
+@z
+@x module 883
+  if not is_char_node(s) then if next_break(cur_p)<>null then
+    if cur_break(next_break(cur_p))=s then s:=r;
+@y that subtle bug is no longer possible so we can remove the code
+@z
+@x module 884
+link(s):=r; r:=post_break(q); post_break(q):=null;
+@y
+link(s):=r; r:=post_break(q); post_break(q):=null; post_disc_break:=true;
+@z
+
+377. Pick up a few discretionary hyphens that were lost because of
+the new (cautious) algorithm.
+@x module 914
+@ @d advance_major_tail==begin major_tail:=link(major_tail); incr(r_count);
+    end
+
+@<Create and append a discretionary node as an alternative...@>=
+begin r:=get_node(small_node_size);
+@y
+@ In this repeat loop we will insert another discretionary if |hyf[j-1]| is
+odd, after both branches of the previous discretionary end at position |j-1|.
+Strictly speaking, we aren't justified in doing this, because we don't know
+that a hyphen after |j-1| is truly independent of those branches. But in almost
+all applications we would rather not lose a potentially valuable hyphenation
+point. (Consider the word `difficult', where the letter `c' is in position |j|.)
+
+@d advance_major_tail==begin major_tail:=link(major_tail); incr(r_count);
+    end
+
+@<Create and append a discretionary node as an alternative...@>=
+repeat r:=get_node(small_node_size);
+@z
+@x ibid
+i:=hyphen_passed;
+@y
+i:=hyphen_passed; hyf[i]:=0;
+@z
+@x ibid
+end
+@y
+hyphen_passed:=j-1; link(hold_head):=null;
+until not odd(hyf[j-1])
+@z
+
+378. Undumped trie must also be dumpable again (Breitenlohner, 11 Dec 89)
+@x module 1325
+undump_size(0)(trie_size)('trie size')(j); {|trie_max|}
+for k:=0 to j do undump_hh(trie[k]);
+undump_size(0)(trie_op_size)('trie op size')(j); {|trie_op_ptr|}
+@y
+undump_size(0)(trie_size)('trie size')(j); @+init trie_max:=j;@+tini
+for k:=0 to j do undump_hh(trie[k]);
+undump_size(0)(trie_op_size)('trie op size')(j); @+init trie_op_ptr:=j;@+tini
+@z
+@x ibid
+k:=256;
+while j>0 do
+  begin undump(0)(k-1)(k); undump(1)(j)(x); j:=j-x; op_start[k]:=qo(j);
+@y
+init for k:=0 to 255 do trie_used[k]:=min_quarterword;@+tini
+k:=256;
+while j>0 do
+  begin undump(0)(k-1)(k); undump(1)(j)(x);@+init trie_used[k]:=qi(x);@+tini
+  j:=j-x; op_start[k]:=qo(j);
+@z
+
+379. Allow output routine to access page totals. (Suggested by Frank
+Mittelbach and Chris Rowley, December 1989)
+@x module 421
+begin if page_contents=empty then
+@y
+begin if (page_contents=empty) and (not output_active) then
+@z
+
+380. Slightly more robust recovery and detection of \output anomalies.
+(Suggested by Chris Thompson, provoked by George Russell, January 1990)
+@x module 1026
+begin if loc<>null then @<Recover from an unbalanced output routine@>;
+@y
+begin if (loc<>null) or 
+ ((token_type<>output_text)and(token_type<>backed_up)) then
+  @<Recover from an unbalanced output routine@>;
+@z
+@x module 1027
+help2("Your sneaky output routine has fewer real {'s than }'s.")@/
+@y
+help2("Your sneaky output routine has problematic {'s and/or }'s.")@/
+@z
+
+381. \eqno\aftergroup*$$ should yield * after the $$ (Michael Downes, 29 Jan 90)
+@x module 1194
+  begin cur_mlist:=p; cur_style:=text_style; mlist_penalties:=false;
+@y
+  begin @<Check that another \.\$ follows@>;
+  cur_mlist:=p; cur_style:=text_style; mlist_penalties:=false;
+@z
+@x ibid
+else  begin @<Check that another \.\$ follows@>;
+@y
+else  begin if a=null then @<Check that another \.\$ follows@>;
+@z
+
+382. Missed a case in the 8-bit change (Wayne Sullivan, 1 Feb 1990)
+@x module 360
+    begin if (end_line_char<0)or(end_line_char>127) then incr(limit);
+@y
+    begin if end_line_char_inactive then incr(limit);
+@z
+
+383. Linebreaking needs to be more robust when total demerits get
+very high (Frank Mittelbach, 22 Feb 1990)
+@x module 830
+@!artificial_badness:boolean; {has |b| been forced to zero?}
+@y
+@!artificial_demerits:boolean; {has |d| been forced to zero?}
+@z
+@x module 833 (this change is cosmetic only)
+@!minimal_demerits:array[very_loose_fit..tight_fit] of scaled; {best total
+  demerits known for current line class and position, given the fitness}
+@!minimum_demerits:scaled; {best total demerits known for current line class
+@y
+@!minimal_demerits:array[very_loose_fit..tight_fit] of integer; {best total
+  demerits known for current line class and position, given the fitness}
+@!minimum_demerits:integer; {best total demerits known for current line class
+@z
+@x module 836 here we want to ensure that total_demerits < awful_bad
+minimum_demerits:=minimum_demerits+abs(adj_demerits);
+@y
+if abs(adj_demerits)>=awful_bad-minimum_demerits then
+  minimum_demerits:=awful_bad-1
+else minimum_demerits:=minimum_demerits+abs(adj_demerits);
+@z
+@x module 851
+begin @!stat artificial_badness:=false;@+tats@/
+@y
+begin artificial_demerits:=false;@/
+@z
+@x module 854
+  begin b:=0; {set badness zero, this break is forced}
+  @!stat artificial_badness:=true;@+tats
+  end
+@y
+  artificial_demerits:=true {set demerits zero, this break is forced}
+@z
+@x module 855
+@<Compute the demerits, |d|, from |r| to |cur_p|@>;
+@y
+if artificial_demerits then d:=0
+else @<Compute the demerits, |d|, from |r| to |cur_p|@>;
+@z
+@x module 856
+if artificial_badness then print_char("*")@+else print_int(b);
+@.*\relax@>
+print(" p="); print_int(pi);
+print(" d="); print_int(d);
+@y
+if b>inf_bad then print_char("*")@+else print_int(b);
+@.*\relax@>
+print(" p="); print_int(pi); print(" d=");
+if artificial_demerits then print_char("*")@+else print_int(d);
+@z
+@x module 859
+d:=line_penalty+b; d:=d*d;
+@y
+begin d:=line_penalty+b;
+if abs(d)>=10000 then d:=100000000@+else d:=d*d;
+@z
+@x ibid
+if abs(fit_class-fitness(r))>1 then d:=d+adj_demerits
+@y
+if abs(fit_class-fitness(r))>1 then d:=d+adj_demerits;
+end
+@z
+
+384. Math fonts may disappear outside of \eqno (Marc van Leeuwen).
+@x module 1194
+  if danger then flush_math;
+@y
+  danger:=false;
+  @<Check that the necessary fonts for math symbols are present;
+    if not, flush the current math lists and set |danger:=true|@>;
+@z
+
+385. Forgot to rule out charnode when testing for node type (Marc van Leeuwen).
+@x module 805
+  begin if type(q)=unset_node then
+    @<Set the unset box |q| and the unset boxes in it@>
+  else if type(q)=rule_node then
+    @<Make the running dimensions in rule |q| extend to the
+      boundaries of the alignment@>;
+@y
+  begin if not is_char_node(q) then
+    if type(q)=unset_node then
+      @<Set the unset box |q| and the unset boxes in it@>
+    else if type(q)=rule_node then
+      @<Make the running dimensions in rule |q| extend to the
+        boundaries of the alignment@>;
+@z
+@x module 903
+if type(hb)=ligature_node then if odd(subtype(hb)) then
+@y
+if not is_char_node(hb) then
+ if type(hb)=ligature_node then if odd(subtype(hb)) then
+@z
+@x module 1202
+  if p<>null then if type(p)=glue_node then d:=0;
+@y
+  if p<>null then if not is_char_node(p) then if type(p)=glue_node then d:=0;
+@z
+
+386. Don't change the font of punctuation before a hyphenated word
+     (Scott Allendorf, reported 7 Mar 90)
+@x module 895
+label common_ending,done,found,found1,not_found,not_found+1,exit;
+@y
+label common_ending,done,found,found1,found2,not_found,exit;
+@z
+@x module 903
+if is_char_node(ha) then
+  begin init_list:=ha; init_lig:=false; hu[0]:=qo(character(ha));
+  end
+else if type(ha)=ligature_node then
+  begin init_list:=lig_ptr(ha); init_lig:=true; init_lft:=(subtype(ha)>1);
+  hu[0]:=qo(character(lig_char(ha)));
+  if init_list=null then if init_lft then
+    begin hu[0]:=256; init_lig:=false;
+    end; {in this case a ligature will be reconstructed from scratch}
+  free_node(ha,small_node_size);
+  end
+else goto not_found+1; {no punctuation found}
+s:=cur_p; {we have |cur_p<>ha| because |type(cur_p)=glue_node|}
+while link(s)<>ha do s:=link(s);
+j:=0; goto common_ending;
+not_found+1: j:=1; s:=ha; init_list:=null;
+if not is_char_node(r) then if type(r)=ligature_node then
+ if subtype(r)>1 then
+  begin j:=0; hu[0]:=256; init_lig:=false;
+  end;
+@y
+if is_char_node(ha) then
+  if font(ha)<>hf then goto found2
+  else begin init_list:=ha; init_lig:=false; hu[0]:=qo(character(ha));
+    end
+else if type(ha)=ligature_node then
+  if font(lig_char(ha))<>hf then goto found2
+  else begin init_list:=lig_ptr(ha); init_lig:=true; init_lft:=(subtype(ha)>1);
+    hu[0]:=qo(character(lig_char(ha)));
+    if init_list=null then if init_lft then
+      begin hu[0]:=256; init_lig:=false;
+      end; {in this case a ligature will be reconstructed from scratch}
+    free_node(ha,small_node_size);
+    end
+else begin {no punctuation found; look for left boundary}
+  if not is_char_node(r) then if type(r)=ligature_node then
+   if subtype(r)>1 then goto found2;
+  j:=1; s:=ha; init_list:=null; goto common_ending;
+  end;
+s:=cur_p; {we have |cur_p<>ha| because |type(cur_p)=glue_node|}
+while link(s)<>ha do s:=link(s);
+j:=0; goto common_ending;
+found2: s:=ha; j:=0; hu[0]:=256; init_lig:=false; init_list:=null;
+@z
+
+387. Balance the parens showing on the terminal (for Lispers).
+@x module 304
+@!in_open : 0..max_in_open; {the number of lines in the buffer, less one}
+@y
+@!in_open : 0..max_in_open; {the number of lines in the buffer, less one}
+@!open_parens : 0..max_in_open; {the number of open text files}
+@z
+@x module 331
+in_open:=0; max_buf_stack:=0;
+@y
+in_open:=0; open_parens:=0; max_buf_stack:=0;
+@z
+@x module 362
+  begin print_char(")"); force_eof:=false;
+  update_terminal; {show user that file has been read}
+@y
+  begin print_char(")"); decr(open_parens);
+  update_terminal; {show user that file has been read}
+  force_eof:=false;
+@z
+@x module 537
+print_char("("); print(name); update_terminal; state:=new_line;
+@y
+print_char("("); incr(open_parens); print(name); update_terminal;
+state:=new_line;
+@z
+@x module 1334
+if job_name=0 then open_log_file;
+@y
+if job_name=0 then open_log_file;
+while open_parens>0 do
+  begin print(" )"); decr(open_parens);
+  end;
+@z
+
+388. Optimize \ifx\p\q after \let\p=\q (Marc van Leeuwen says that
+  AmS-TeX uses this a lot).
+@x module 508
+  while (p<>null)and(q<>null) do
+  if info(p)<>info(q) then p:=null
+  else  begin p:=link(p); q:=link(q);
+    end;
+b:=((p=null)and(q=null));
+@y
+if p=q then b:=true
+else begin while (p<>null)and(q<>null) do
+    if info(p)<>info(q) then p:=null
+    else  begin p:=link(p); q:=link(q);
+      end;
+  b:=((p=null)and(q=null));
+  end;
+@z
+@x module 538 (while we're at it, might as well optimize this too)
+begin if not input_ln(cur_file,false) then do_nothing;
+@y
+begin if input_ln(cur_file,false) then do_nothing;
+@z
+@x module 1020 (and this)
+else  begin wait:=false; s:=ins_ptr(p);
+  link(last_ins_ptr(r)):=s; s:=last_ins_ptr(r);
+@y
+else  begin wait:=false; s:=last_ins_ptr(r); link(s):=ins_ptr(p);
+@z
+
+389. Treat migration properly in displays (Marc van Leeuwen).
+@x module 1199 (a bad bug that really has bitten)
+adjust_tail:=adjust_head; b:=hpack(p,natural);
+@y
+adjust_tail:=adjust_head; b:=hpack(p,natural); p:=list_ptr(b);
+@z
+@x module 1204
+shift_amount(b):=s+d; append_to_vlist(b);
+if t<>adjust_head then
+  begin link(tail):=link(adjust_head); tail:=t;
+   end
+@y
+shift_amount(b):=s+d; append_to_vlist(b)
+@z
+@x module 1205
+  tail_append(new_penalty(post_display_penalty));
+  end
+else  begin tail_append(new_penalty(post_display_penalty));
+  tail_append(new_param_glue(g2));
+  end
+@y
+  g2:=0;
+  end;
+if t<>adjust_head then {migrating material comes after equation number}
+  begin link(tail):=link(adjust_head); tail:=t;
+  end;
+tail_append(new_penalty(post_display_penalty));
+if g2>0 then tail_append(new_param_glue(g2))
+@z
+
+-----------Here I draw the line with respect to further changes
+
+390. Uninitialized nullfont parameters (found by Lance Carnes, 11 May 90).
+@x module 552
+hyphen_char[null_font]:="-"; skew_char[null_font]:=-1;
+@y
+hyphen_char[null_font]:="-"; skew_char[null_font]:=-1;
+bchar_label[null_font]:=non_address;
+font_bchar[null_font]:=non_char; font_false_bchar[null_font]:=non_char;
+@z
+
+391. Disable \write{\the\prevgraf} (B. Jackowski, July 1990).
+@x module 422
+begin nest[nest_ptr]:=cur_list; p:=nest_ptr;
+while abs(nest[p].mode_field)<>vmode do decr(p);
+scanned_result(nest[p].pg_field)(int_val);
+end
+@y
+if mode=0 then scanned_result(0)(int_val) {|prev_graf=0| within \.{\\write}}
+else begin nest[nest_ptr]:=cur_list; p:=nest_ptr;
+  while abs(nest[p].mode_field)<>vmode do decr(p);
+  scanned_result(nest[p].pg_field)(int_val);
+  end
+@z
+
+392. Report correct line number when buffer overflows (George Russell).
+@x module 538
+begin if input_ln(cur_file,false) then do_nothing;
+firm_up_the_line;
+if end_line_char_inactive then decr(limit)
+else  buffer[limit]:=end_line_char;
+first:=limit+1; loc:=start; line:=1;
+@y
+begin line:=1;
+if input_ln(cur_file,false) then do_nothing;
+firm_up_the_line;
+if end_line_char_inactive then decr(limit)
+else  buffer[limit]:=end_line_char;
+first:=limit+1; loc:=start;
+@z
+
+-------------
+Note: When making change 376, I forgot to delete the redundant
+code in module 883, and I should also have changed the name of that
+module. These cosmetic changes (and some changes to the comments)
+were made in version 3.14, in addition to the following two changes.
+-------------
+
+393. Show unprintable characters in font id's (Wayne Sullivan, Dec 1990)
+@x module 63
+print(s);
+@y
+slow_print(s);
+@z
+@x module 262 can now be spruced up
+else  begin print_esc(""); slow_print(text(p));
+@y
+else  begin print_esc(text(p));
+@z
+@x and module 263 likewise
+else  begin print_esc(""); slow_print(text(p));
+  end;
+@y
+else print_esc(text(p));
+@z
+
+394. Avoid range check if total_pages>65535 (Eberhard Mattes, Dec 1990)
+@x module 642
+  dvi_out(total_pages div 256); dvi_out(total_pages mod 256);@/
+@y
+  dvi_out((total_pages div 256) mod 256); dvi_out(total_pages mod 256);@/
+@z
+
+395. Less confusing error message (18 Sep 91)
+@x module 436
+  begin print_err("Bad math code");
+@.Bad math code@>
+  help2("A numeric math code must be between 0 and 32767.")@/
+@y (because a \mathcode can be 32768, but not a \mathchar)
+  begin print_err("Bad mathchar");
+@.Bad mathchar@>
+  help2("A mathchar number must be between 0 and 32767.")@/
+@z
+
+396. Internal strings should not be expanded even if unprintable;
+i.e., selector=new_string => print(c)==print_char(c), print(s)==slow_print(s).
+This change completes what I began with number 393 (18 Sep 91).
+@x modules 59 and 60 (same change to both)
+  else if (@<Character |s| is the current new-line character@>) then
+    if selector<pseudo then
+      begin print_ln; return;
+      end;
+@y
+  else if selector>pseudo then
+      begin print_char(s); return; {internal strings are not expanded}
+      end
+    else if (@<Character |s| is the current new-line character@>) then
+      if selector<pseudo then
+        begin print_ln; return;
+        end;
+@z
+@x module 61
+else  begin print(format_ident); print_ln;
+@y
+else  begin slow_print(format_ident); print_ln;
+@z
+@x module 84
+  print(input_stack[base_ptr].name_field);
+@y
+  slow_print(input_stack[base_ptr].name_field);
+@z
+@x module 518
+begin print(a); print(n); print(e);
+@y
+begin slow_print(a); slow_print(n); slow_print(e);
+@z
+@x module 536
+print(format_ident); print("  ");
+@y
+slow_print(format_ident); print("  ");
+@z
+@x module 537
+print_char("("); incr(open_parens); print(name); update_terminal;
+@y
+print_char("("); incr(open_parens); slow_print(name); update_terminal;
+@z
+@x module 581
+  print(font_name[f]); print_char("!"); end_diagnostic(false);
+@y
+  slow_print(font_name[f]); print_char("!"); end_diagnostic(false);
+@z
+@x module 642
+  print_nl("Output written on "); print(output_file_name);
+@y
+  print_nl("Output written on "); slow_print(output_file_name);
+@z
+@x module 1261
+set_font:begin print("select font "); print(font_name[chr_code]);
+@y
+set_font:begin print("select font "); slow_print(font_name[chr_code]);
+@z
+@x module 1280
+print(s); update_terminal;
+@y
+slow_print(s); update_terminal;
+@z
+@x module 1283
+begin print_err(s);
+@y
+begin print_err(""); slow_print(s);
+@z
+@x module 1328
+print(w_make_name_string(fmt_file)); flush_string;
+print_nl(format_ident)
+@y
+slow_print(w_make_name_string(fmt_file)); flush_string;
+print_nl(""); slow_print(format_ident)
+@z
+@x module 1333
+    print(log_name); print_char(".");
+@y
+    slow_print(log_name); print_char(".");
+@z
+@x module 1339
+10: print(n);
+@y
+10: slow_print(n);
+@z
+
+397. Retain more right context for reconstructing ligatures (19 Sep 91)
+@x module 892
+@!l_hyf,@!r_hyf:integer; {limits on fragment sizes}
+@y
+@!l_hyf,@!r_hyf:integer; {limits on fragment sizes}
+@!hyf_bchar:halfword; {boundary character after $c_n$}
+@z
+@x module 897
+    c:=qo(character(s));
+@y
+    hyf_bchar:=character(s); c:=qo(hyf_bchar);
+@z
+@x module 897 again
+  s:=link(s);
+@y
+  s:=link(s); hyf_bchar:=non_char;
+@z
+@x module 898
+j:=hn; q:=lig_ptr(s);
+@y
+j:=hn; q:=lig_ptr(s);@+if q>null then hyf_bchar:=character(q);
+@z
+@x module 903
+q:=link(hb); link(hb):=null; r:=link(ha); link(ha):=null; bchar:=non_char;
+@y
+q:=link(hb); link(hb):=null; r:=link(ha); link(ha):=null; bchar:=hyf_bchar;
+@z
+
+398. Patch the previous code, which could cause double kerning (CET1, 29 Sep 91)
+@x module 897
+    hb:=s; incr(hn); hu[hn]:=c; hc[hn]:=lc_code(c);
+    end
+  else if type(s)=ligature_node then
+    @<Move the characters of a ligature node to |hu| and |hc|;
+      but |goto done3| if they are not all letters@>
+  else if (type(s)<>kern_node)or(subtype(s)<>normal) then goto done3;
+  s:=link(s); hyf_bchar:=non_char;
+@y
+    hb:=s; incr(hn); hu[hn]:=c; hc[hn]:=lc_code(c); hyf_bchar:=non_char;
+    end
+  else if type(s)=ligature_node then
+    @<Move the characters of a ligature node to |hu| and |hc|;
+      but |goto done3| if they are not all letters@>
+  else if (type(s)=kern_node)and(subtype(s)=normal) then hb:=s
+  else goto done3;
+  s:=link(s);
+@z
+@x module 898
+hb:=s; hn:=j;
+@y
+hb:=s; hn:=j;
+if odd(subtype(s)) then hyf_bchar:=font_bchar[hf]@+else hyf_bchar:=non_char;
+@z
+@x module 903
+if not is_char_node(hb) then
+ if type(hb)=ligature_node then if odd(subtype(hb)) then
+  bchar:=font_bchar[hf];
+@y
+@z
+
+399. Disallow \setbox in do_assignments (problem found by Robert Hunt, Nov 91)
+@x module 76
+@!deletions_allowed:boolean; {is it safe for |error| to call |get_token|?}
+@y
+@!deletions_allowed:boolean; {is it safe for |error| to call |get_token|?}
+@!set_box_allowed:boolean; {is it safe to do a \.{\\setbox} assignment?}
+@z
+@x module 77
+deletions_allowed:=true; error_count:=0; {|history| is initialized elsewhere}
+@y
+deletions_allowed:=true; set_box_allowed:=true;
+error_count:=0; {|history| is initialized elsewhere}
+@z
+@x module 1241
+  scan_optional_equals; scan_box(box_flag+n);
+@y
+  if set_box_allowed then scan_box(box_flag+n)
+  else begin print_err("Improper "); print_esc("setbox");
+@.Improper \\setbox@>
+    help2("Sorry, \setbox is not allowed after \halign in a display,")@/
+    ("or between \accent and an accented character."); error;
+    end;
+@z
+@x module 1270
+  prefixed_command;
+@y
+  set_box_allowed:=false; prefixed_command; set_box_allowed:=true;
+@z
+
+400. Defend against negative cur_mu (Wayne Sullivan, Nov 91)
+@x module 716
+begin n:=x_over_n(m,@'200000); f:=remainder;@/
+@y
+begin n:=x_over_n(m,@'200000); f:=remainder;@/
+if f<0 then
+  begin decr(n); f:=f+@'200000;
+  end;
+@z
+@x module 717
+  begin n:=x_over_n(m,@'200000); f:=remainder;@/
+@y
+  begin n:=x_over_n(m,@'200000); f:=remainder;@/
+  if f<0 then
+    begin decr(n); f:=f+@'200000;
+    end;
+@z
+
+401. Defend against `|}{|' in |\read| (Michael Downes).
+@x module 483
+  store_new_token(cur_tok);
+@y
+  if align_state<1000000 then {unmatched `\.\}' aborts the line}
+    begin repeat get_token; until cur_tok=0;
+    align_state:=1000000; goto done;
+    end;
+  store_new_token(cur_tok);
+@z
+
+402. Economize string storage under multiple \font defs (B. Jackowski)
+@x module 1257
+@!old_setting:0..max_selector; {holds |selector| setting}
+@y
+@!old_setting:0..max_selector; {holds |selector| setting}
+@!flushable_string:str_number; {string not yet referenced}
+@z
+@x module 1260
+for f:=font_base+1 to font_ptr do
+  if str_eq_str(font_name[f],cur_name)and str_eq_str(font_area[f],cur_area) then
+    begin if s>0 then
+@y
+flushable_string:=str_ptr-1;
+for f:=font_base+1 to font_ptr do
+  if str_eq_str(font_name[f],cur_name)and str_eq_str(font_area[f],cur_area) then
+    begin if cur_name=flushable_string then
+      begin flush_string; cur_name:=font_name[f];
+      end;
+    if s>0 then
+@z
+
+403. Don't look for \newlinechar within unprintable chars (B. Raichle, Nov 91)
+@x module 59
+var j:pool_pointer; {current character code position}
+@y
+var j:pool_pointer; {current character code position}
+@!nl:integer; {new-line character to restore}
+@z
+@x
+  else if selector>pseudo then
+      begin print_char(s); return; {internal strings are not expanded}
+      end
+    else if (@<Character |s| is the current new-line character@>) then
+      if selector<pseudo then
+        begin print_ln; return;
+        end;
+@y
+  else begin if selector>pseudo then
+      begin print_char(s); return; {internal strings are not expanded}
+      end;
+    if (@<Character |s| is the current new-line character@>) then
+      if selector<pseudo then
+        begin print_ln; return;
+        end;
+    nl:=new_line_char; new_line_char:=-1;
+      {temporarily disable new-line character}
+    j:=str_start[s];
+    while j<str_start[s+1] do
+      begin print_char(so(str_pool[j])); incr(j);
+      end;
+    new_line_char:=nl; return;
+    end;
+@z
+@x module 60
+label exit;
+var j:pool_pointer; {current character code position}
+begin if s>=str_ptr then s:="???" {this can't happen}
+@.???@>
+else if s<256 then
+  if s<0 then s:="???" {can't happen}
+  else if selector>pseudo then
+      begin print_char(s); return; {internal strings are not expanded}
+      end
+    else if (@<Character |s| is the current new-line character@>) then
+      if selector<pseudo then
+        begin print_ln; return;
+        end;
+j:=str_start[s];
+while j<str_start[s+1] do
+  begin print(so(str_pool[j])); incr(j);
+  end;
+exit:end;
+label exit;
+var j:pool_pointer; {current character code position}
+begin if s>=str_ptr then s:="???" {this can't happen}
+@.???@>
+else if s<256 then
+  if s<0 then s:="???" {can't happen}
+  else if selector>pseudo then
+      begin print_char(s); return; {internal strings are not expanded}
+      end
+    else if (@<Character |s| is the current new-line character@>) then
+      if selector<pseudo then
+        begin print_ln; return;
+        end;
+j:=str_start[s];
+while j<str_start[s+1] do
+  begin print(so(str_pool[j])); incr(j);
+  end;
+exit:end;
+@y
+var j:pool_pointer; {current character code position}
+begin if (s>=str_ptr) or (s<256) then print(s)
+else begin j:=str_start[s];
+  while j<str_start[s+1] do
+    begin print(so(str_pool[j])); incr(j);
+    end;
+  end;
+end;
+@z
+
+404. False boundary character logic was incorrect (found by Eberhard
+  Mattes and Bernd Raichle, 6 Feb 92)
+@x module 1036
+cur_q:=tail; cur_l:=cur_r; {or |character(lig_stack)|}
+@y the following is needed since cur_r might have been changed to non_char
+cur_q:=tail; cur_l:=character(lig_stack);
+@z
+
+405. New paragraph and resume-after-display should continue current
+  \language (Sch\"opf and Thompson, 17 July 92)
+@@@ Undo the changes to modules 212, 213, 215 in change number 373.
+@x module 218
+  if m=hmode then@+if(nest[p].lhm_field<>2)or(nest[p].rhm_field<>3)then
+    begin print(" (hyphenmin "); print_int(nest[p].lhm_field); print_char(",");
+    print_int(nest[p].rhm_field); print_char(")");
+    end;
+@y
+  if m=hmode then if (nest[p].pg_field <> @'40600000) then
+    begin print(" (language"); print_int(nest[p].pg_field mod @'200000);
+    print(":hyphenmin"); print_int(nest[p].pg_field div @'20000000);
+    print_char(","); print_int((nest[p].pg_field div @'200000) mod @'100);
+    print_char(")");
+    end;
+@z
+@x module 816
+pop_nest;
+@y prev_graf now carries the language parameters at start of horizontal mode
+init_cur_lang:=prev_graf mod @'200000;
+init_l_hyf:=prev_graf div @'20000000;
+init_r_hyf:=(prev_graf div @'200000) mod @'100;
+pop_nest;
+@z
+@x module 891
+l_hyf:=lhmin; r_hyf:=rhmin; cur_lang:=0;
+@y
+cur_lang:=init_cur_lang; l_hyf:=init_l_hyf; r_hyf:=init_r_hyf;
+@z
+@x module 892
+@!cur_lang:ASCII_code; {current hyphenation table of interest}
+@!l_hyf,@!r_hyf:integer; {limits on fragment sizes}
+@y
+@!cur_lang,@!init_cur_lang:ASCII_code; {current hyphenation table of interest}
+@!l_hyf,@!r_hyf,@!init_l_hyf,@!init_r_hyf:integer; {limits on fragment sizes}
+@z
+@x module 1091
+lhmin:=norm_min(left_hyphen_min); rhmin:=norm_min(right_hyphen_min);
+push_nest; mode:=hmode; space_factor:=1000; clang:=0;@/
+@y
+push_nest; mode:=hmode; space_factor:=1000; set_cur_lang; clang:=cur_lang;
+prev_graf:=(norm_min(left_hyphen_min)*@'100+norm_min(right_hyphen_min))
+             *@'200000+cur_lang;
+@z
+@x module 1200
+push_nest; mode:=hmode; space_factor:=1000; clang:=0;
+@y
+push_nest; mode:=hmode; space_factor:=1000; set_cur_lang; clang:=cur_lang;
+prev_graf:=(norm_min(left_hyphen_min)*@'100+norm_min(right_hyphen_min))
+             *@'200000+cur_lang;
+@z
+
+406. Avoid (harmless) range errors (Philip Taylor and CET1, 17 Dec 92).
+@x module 934
+var n:small_number; {length of current word}
+@!j:small_number; {an index into |hc|}
+@y
+var n:0..64; {length of current word; not always a |small_number|}
+@!j:0..64; {an index into |hc|}
+@z
+@x module 960
+var k,@!l:small_number; {indices into |hc| and |hyf|}
+@y
+var k,@!l:0..64; {indices into |hc| and |hyf|;
+                  not always in |small_number| range}
+@z
+
+407. Kerns inserted via boundary chars should not disappear (William E. Baxter,
+     25 Feb 93)
+@x module 837
+Kern nodes for accents are treated specially: They do not
+disappear at a line break.
+@y
+Kern nodes do not disappear at a line break unless they are |explicit|.
+@z
+@x ibid
+  math_node,kern_node: if subtype(s)=acc_kern then goto done
+    else break_width[1]:=break_width[1]-width(s);
+@y
+  math_node: break_width[1]:=break_width[1]-width(s);
+  kern_node: if subtype(s)<>explicit then goto done
+    else break_width[1]:=break_width[1]-width(s);
+@z
+@x module 839
+plus $l_1$, so the length from |cur_p| to |cur_p| should be $\gamma+l_0+l_1-l$,
+minus the length of nodes that will be discarded after the discretionary break.
+@y (this change and the next two should have been made long ago, with #376!)
+plus $l_1$, so the length from |cur_p| to |cur_p| should be $\gamma+l_0+l_1-l$.
+If the post-break text of the discretionary is empty, a break may also
+discard~|q|; in that unusual case we subtract the length of~|q| and any
+other nodes that will be discarded after the discretionary break.
+@z
+@x module 840
+  begin @<Add the width of node |s| to |break_width| and increase |t|,
+    unless it's discardable@>;
+  s:=link(s);
+  end;
+break_width[1]:=break_width[1]+disc_width;
+if t=0 then s:=link(v); {more nodes may also be discardable after the break}
+@y
+  begin @<Add the width of node |s| to |break_width|@>;
+  s:=link(s);
+  end;
+break_width[1]:=break_width[1]+disc_width;
+if post_break(cur_p)=null then s:=link(v);
+          {nodes may be discardable after the break}
+@z
+@x module 842 (which now has a new title)
+  hlist_node,vlist_node,rule_node:break_width[1]:=break_width[1]+width(s);
+  kern_node: if (t=0)and(subtype(s)<>acc_kern) then t:=-1 {discardable}
+  othercases confusion("disc2")
+@:this can't happen disc2}{\quad disc2@>
+  endcases;
+incr(t)
+@y
+  hlist_node,vlist_node,rule_node,kern_node:
+    break_width[1]:=break_width[1]+width(s);
+  othercases confusion("disc2")
+@:this can't happen disc2}{\quad disc2@>
+  endcases
+@z
+@x module 866
+kern_node: kern_break;
+@y
+kern_node: if subtype(cur_p)=explicit then kern_break
+  else act_width:=act_width+width(cur_p);
+@z
+@x module 868
+  else if precedes_break(prev_p) then try_break(0,unhyphenated);
+@y
+  else if precedes_break(prev_p) then try_break(0,unhyphenated)
+  else if (type(prev_p)=kern_node)and(subtype(prev_p)<>explicit) then
+    try_break(0,unhyphenated);
+@z
+@x module 879
+  if subtype(q)=acc_kern then if type(q)=kern_node then goto done1;
+@y
+  if type(q)=kern_node then if subtype(q)<>explicit then goto done1;
+@z
+
+408. Prevent boundary kern from disappearing after hyphenation (25 Feb 93)
+@x module 897
+  else if (type(s)=kern_node)and(subtype(s)=normal) then hb:=s
+@y
+  else if (type(s)=kern_node)and(subtype(s)=normal) then
+    begin hb:=s;
+    hyf_bchar:=font_bchar[hf];
+    end
+@z
+
+409. Avoid potential future bug [P Breitenlohner] (26 Jun 93)
+@x module 628 [shift_amount(leader_box)=0 now but maybe not in extensions]
+dvi_v:=save_v; dvi_h:=save_h; cur_v:=save_v;
+@y
+dvi_v:=save_v; dvi_h:=save_h; cur_v:=base_line;
+@z
+@x module 637
+dvi_v:=save_v; dvi_h:=save_h; cur_h:=save_h;
+@y
+dvi_v:=save_v; dvi_h:=save_h; cur_h:=left_edge;
+@z
+
+410. Mustn't let |non-address| depend on |font_mem_size|
+@x module 549
+@d non_address==font_mem_size {a spurious |font_index|}
+@y
+@d non_address=0 {a spurious |bchar_label|}
+@z
+@x module 916
+if bchar_label[hf]<non_address then {put left boundary at beginning of new line}
+@y
+if bchar_label[hf]<>non_address then {put left boundary at beginning of new line}
+@z
+@x module 1323, this will detect obsolete format files
+undump(0)(font_mem_size)(bchar_label[k]);
+@y
+undump(0)(fmem_ptr-1)(bchar_label[k]);
+@z
+
+411. Allow large |font_mem_size|, many font parameters.
+@x module 549
+@!font_params:array[internal_font_number] of halfword; {how many font
+@y
+@!font_params:array[internal_font_number] of font_index; {how many font
+@z
+
+412. Math kerns are explicit; this matters, after change 405 (W Carlip, Sep 94)
+@x module 717
+  width(p):=mu_mult(width(p)); subtype(p):=normal;
+@y
+  width(p):=mu_mult(width(p)); subtype(p):=explicit;
+@z
+
+413. Avoid overflow on real-to-integer conversion
+@x module 619
+@!edge:scaled; {left edge of sub-box, or right edge of leader space}
+@y
+@!edge:scaled; {left edge of sub-box, or right edge of leader space}
+@!glue_temp:real; {glue value before rounding}
+@z
+@x module 625
+@ @<Move right or output leaders@>=
+begin g:=glue_ptr(p); rule_wd:=width(g);
+if g_sign<>normal then
+  begin if g_sign=stretching then
+    begin if stretch_order(g)=g_order then
+      rule_wd:=rule_wd+round(float(glue_set(this_box))*stretch(g));
+@^real multiplication@>
+    end
+  else  begin if shrink_order(g)=g_order then
+      rule_wd:=rule_wd-round(float(glue_set(this_box))*shrink(g));
+@y
+@ @d vet_glue(#)== glue_temp:=#;
+  if glue_temp>float_constant(1000000000) then
+           glue_temp:=float_constant(1000000000)
+  else if glue_temp<-float_constant(1000000000) then
+           glue_temp:=-float_constant(1000000000)
+
+@<Move right or output leaders@>=
+begin g:=glue_ptr(p); rule_wd:=width(g);
+if g_sign<>normal then
+  begin if g_sign=stretching then
+    begin if stretch_order(g)=g_order then
+      begin vet_glue(float(glue_set(this_box))*stretch(g));
+@^real multiplication@>
+      rule_wd:=rule_wd+round(glue_temp);
+      end;
+    end
+  else if shrink_order(g)=g_order then
+    begin vet_glue(float(glue_set(this_box))*shrink(g));
+      rule_wd:=rule_wd-round(glue_temp);
+@z
+@x module 629
+@!edge:scaled; {bottom boundary of leader space}
+@y
+@!edge:scaled; {bottom boundary of leader space}
+@!glue_temp:real; {glue value before rounding}
+@z
+@x module 634
+      rule_ht:=rule_ht+round(float(glue_set(this_box))*stretch(g));
+@^real multiplication@>
+    end
+  else  begin if shrink_order(g)=g_order then
+      rule_ht:=rule_ht-round(float(glue_set(this_box))*shrink(g));
+@y
+      begin vet_glue(float(glue_set(this_box))*stretch(g));
+@^real multiplication@>
+      rule_ht:=rule_ht+round(glue_temp);
+      end;
+    end
+  else if shrink_order(g)=g_order then
+    begin vet_glue(float(glue_set(this_box))*shrink(g));
+    rule_ht:=rule_ht-round(glue_temp);
+@z
+
+414. final cleanup should not retain spurious reference counts (20 Mar 95)
+@x module 1335
+while open_parens>0 do
+@y
+while input_ptr>0 do
+  if state=token_list then end_token_list@+else end_file_reading;
+while open_parens>0 do
+@z
+@x module 1335, continued
+  cur_if:=subtype(cond_ptr); cond_ptr:=link(cond_ptr);
+@y
+  cur_if:=subtype(cond_ptr); temp_ptr:=cond_ptr;
+  cond_ptr:=link(cond_ptr); free_node(temp_ptr,if_node_size);
+@z
+@x module 1335, concluded
+  begin @!init store_fmt_file; return;@+tini@/
+@y
+  begin @!init for c:=top_mark_code to split_bot_mark_code do
+    if cur_mark[c]<>null then delete_token_ref(cur_mark[c]);
+  store_fmt_file; return;@+tini@/
+@z
+
+415. we need not raise hassles about two-digit years (23 Nov 98)
+@x module 1328
+print_int(year mod 100); print_char(".");
+@y
+print_int(year); print_char(".");
+@z
+
+416. \xleaders often drops the final box (Hiroshi Nakashima, 12 July 99)
+@x modules 627 and 636
+  else  begin lx:=(2*lr+lq+1) div (2*lq+2); {round|(lr/(lq+1))|}
+@y
+  else  begin lx:=lr div (lq+1);
+@z
+
+417. disallow 100000 unbalanced }s outside of alignment (Ralf Roth, 30 Aug 01)
+@x module 789
+to another alignment is being scanned.
+
+@<Insert the \(v)\<v_j>...@>=
+begin if scanner_status=aligning then
+@y
+to another alignment is being scanned, or when no alignment preamble is active.
+
+@<Insert the \(v)\<v_j>...@>=
+begin if (scanner_status=aligning) or (cur_align=null) then
+@z
+
+418. don't allow end-template except at end of template (Roth, 30 Aug 01)
+@x module 325
+while (state=token_list)and(loc=null) do end_token_list; {conserve stack space}
+@y
+while (state=token_list)and(loc=null)and(token_type<>v_template) do
+  end_token_list; {conserve stack space}
+@z
+@x module 390
+while (state=token_list)and(loc=null) do end_token_list; {conserve stack space}
+@y
+while (state=token_list)and(loc=null)and(token_type<>v_template) do
+  end_token_list; {conserve stack space}
+@z
+@x module 1131
+during an entire alignment, until |fin_align| removes it.
+
+@<Declare act...@>=
+procedure do_endv;
+begin if cur_group=align_group then
+@y
+during an entire alignment, until |fin_align| removes it.
+
+A devious user might force an |endv| command to occur just about anywhere;
+we must defeat such hacks.
+
+@<Declare act...@>=
+procedure do_endv;
+begin base_ptr:=input_ptr; input_stack[base_ptr]:=cur_input;
+while (input_stack[base_ptr].index_field<>v_template) and
+      (input_stack[base_ptr].loc_field=null) and
+      (input_stack[base_ptr].state_field=token_list) do decr(base_ptr);
+if (input_stack[base_ptr].index_field<>v_template) or
+      (input_stack[base_ptr].loc_field<>null) or
+      (input_stack[base_ptr].state_field<>token_list) then
+  fatal_error("(interwoven alignment preambles are not allowed)");
+@.interwoven alignment preambles...@>
+ if cur_group=align_group then
+@z
+
+419. Improve rounding of glue during output.
+@x module 3
+@!@^dirty \PASCAL@>
+@y
+@!@^dirty \PASCAL@>
+
+Incidentally, \PASCAL's standard |round| function can be problematical,
+because it disagrees with the IEEE floating-point standard.
+Many implementors have
+therefore chosen to substitute their own home-grown rounding procedure.
+@z
+@x module 619
+begin this_box:=temp_ptr; g_order:=glue_order(this_box);
+@y
+@!cur_glue:real; {glue seen so far}
+@!cur_g:scaled; {rounded equivalent of |cur_glue| times the glue ratio}
+begin cur_g:=0; cur_glue:=float_constant(0);
+this_box:=temp_ptr; g_order:=glue_order(this_box);
+@z
+@x module 625
+begin g:=glue_ptr(p); rule_wd:=width(g);
+if g_sign<>normal then
+  begin if g_sign=stretching then
+    begin if stretch_order(g)=g_order then
+      begin vet_glue(float(glue_set(this_box))*stretch(g));
+@^real multiplication@>
+      rule_wd:=rule_wd+round(glue_temp);
+      end;
+    end
+  else if shrink_order(g)=g_order then
+    begin vet_glue(float(glue_set(this_box))*shrink(g));
+      rule_wd:=rule_wd-round(glue_temp);
+    end;
+  end;
+@y
+begin g:=glue_ptr(p); rule_wd:=width(g)-cur_g;
+if g_sign<>normal then
+  begin if g_sign=stretching then
+    begin if stretch_order(g)=g_order then
+      begin cur_glue:=cur_glue+stretch(g);
+      vet_glue(float(glue_set(this_box))*cur_glue);
+@^real multiplication@>
+      cur_g:=round(glue_temp);
+      end;
+    end
+  else if shrink_order(g)=g_order then
+      begin cur_glue:=cur_glue-shrink(g);
+      vet_glue(float(glue_set(this_box))*cur_glue);
+      cur_g:=round(glue_temp);
+      end;
+  end;
+rule_wd:=rule_wd+cur_g;
+@z
+@x module 629
+begin this_box:=temp_ptr; g_order:=glue_order(this_box);
+@y
+@!cur_glue:real; {glue seen so far}
+@!cur_g:scaled; {rounded equivalent of |cur_glue| times the glue ratio}
+begin cur_g:=0; cur_glue:=float_constant(0);
+this_box:=temp_ptr; g_order:=glue_order(this_box);
+@z
+@x module 634
+begin g:=glue_ptr(p); rule_ht:=width(g);
+if g_sign<>normal then
+  begin if g_sign=stretching then
+    begin if stretch_order(g)=g_order then
+      begin vet_glue(float(glue_set(this_box))*stretch(g));
+@^real multiplication@>
+      rule_ht:=rule_ht+round(glue_temp);
+      end;
+    end
+  else if shrink_order(g)=g_order then
+    begin vet_glue(float(glue_set(this_box))*shrink(g));
+    rule_ht:=rule_ht-round(glue_temp);
+    end;
+  end;
+@y
+begin g:=glue_ptr(p); rule_ht:=width(g)-cur_g;
+if g_sign<>normal then
+  begin if g_sign=stretching then
+    begin if stretch_order(g)=g_order then
+      begin cur_glue:=cur_glue+stretch(g);
+      vet_glue(float(glue_set(this_box))*cur_glue);
+@^real multiplication@>
+      cur_g:=round(glue_temp);
+      end;
+    end
+  else if shrink_order(g)=g_order then
+      begin cur_glue:=cur_glue-shrink(g);
+      vet_glue(float(glue_set(this_box))*cur_glue);
+      cur_g:=round(glue_temp);
+      end;
+  end;
+rule_ht:=rule_ht+cur_g;
+@z
+
+420. Error recovery hindered by missing goto statement (reported by
+David Fuchs, September 2007)
+
+@x module 395
+incr(align_state); long_state:=call; cur_tok:=par_token; ins_error;
+@y
+incr(align_state); long_state:=call; cur_tok:=par_token; ins_error;
+goto continue;
+@z
+
+421. Slight improvement to inner loop speed also eliminates a case
+of "dirty Pascal"
+
+@x module 1035
+  begin if character(tail)=qi(hyphen_char[main_f]) then if link(cur_q)>null then
+@y
+  begin if link(cur_q)>null then
+    if character(tail)=qi(hyphen_char[main_f]) then ins_disc:=true;
+@z
+
+422. Amendment to bugfix 414 (reported by David Fuchs, September 2007)
+
+@x module 1335
+  store_fmt_file; return;@+tini@/
+@y
+  if last_glue<>max_halfword then delete_glue_ref(last_glue);
+  store_fmt_file; return;@+tini@/
+@z
+
+423. Remove leaking glue reference after error (DRF, September 2007)
+
+@x module 1236
+  help2("I can't carry out that multiplication or division,")@/
+    ("since the result is out of range.");
+@y
+  help2("I can't carry out that multiplication or division,")@/
+    ("since the result is out of range.");
+  if p>=glue_val then delete_glue_ref(cur_val);
+@z
+
+424. Leaders with muglue is henceforth disallowed (indeed, David Fuchs
+observed that it has never worked, except in 180pt fonts!)
+
+@x module 1078
+if ((cur_cmd=hskip)and(abs(mode)<>vmode))or@|
+   ((cur_cmd=vskip)and(abs(mode)=vmode))or@|
+   ((cur_cmd=mskip)and(abs(mode)=mmode)) then
+@y
+if ((cur_cmd=hskip)and(abs(mode)<>vmode))or@|
+   ((cur_cmd=vskip)and(abs(mode)=vmode)) then
+@z
+
+425. An optimization suggested by Fuchs that I couldn't resist, because
+it improves the inner loop whenever the last letter of a word
+has a lig/kern program. Also another twiddle for the inner loop.
+
+@x module 1039
+if char_tag(main_i)<>lig_tag then goto main_loop_wrapup;
+@y
+if char_tag(main_i)<>lig_tag then goto main_loop_wrapup;
+if cur_r=non_char then goto main_loop_wrapup;
+@z
+@x module 1036
+tail_append(lig_stack) {|main_loop_lookahead| is next}
+@y
+link(tail):=lig_stack; tail:=lig_stack {|main_loop_lookahead| is next}
+@z
+
+426. For robustness, enforce a restriction checked by TFtoPL (suggested
+by DRF)
+
+@x module 365
+if lf<>6+lh+(ec-bc+1)+nw+nh+nd+ni+nl+nk+ne+np then abort;
+@y
+if lf<>6+lh+(ec-bc+1)+nw+nh+nd+ni+nl+nk+ne+np then abort;
+if (nw=0)or(nh=0)or(nd=0)or(ni=0) then abort;
+@z
+
+427. Tell more precisely the effective size of 1:1 insertions (DEK, 27 Feb 08)
+
+@x module 986
+      t:=x_over_n(height(r),1000)*count(t); print_scaled(t);
+@y
+      if count(t)=1000 then t:=height(r)
+      else t:=x_over_n(height(r),1000)*count(t);
+      print_scaled(t);
+@z
+
+428. \csname\endcsname should be followed by space in print_cs, just as all
+other multiletter control sequences are (found by Oleg Bulatov, 14 Sep 2008)
+
+@x module 262
+      begin print_esc("csname"); print_esc("endcsname");
+@y
+      begin print_esc("csname"); print_esc("endcsname"); print_char(" ");
+@z
+
+429. Don't echo error message to terminal when tracing paragraphs
+(Udo Wermuth, 15 January 2017)
+@x module 826
+  begin no_shrink_error_yet:=false;
+@y
+  begin no_shrink_error_yet:=false;
+  @!stat if tracing_paragraphs>0 then end_diagnostic(true);@+tats@;
+@z
+@x
+  error;
+@y
+  error;
+  @!stat if tracing_paragraphs>0 then begin_diagnostic;@+tats@;
+@z
+
+430. Defeat interactions during batch mode (Xiaosa Zhang, 27 June 2020)
+@x module 83
+@ @<Get user's advice...@>=
+loop@+begin continue: clear_for_error_prompt; prompt_input("? ");
+@y
+@ @<Get user's advice...@>=
+loop@+begin continue: if interaction<>error_stop_mode then return;
+  clear_for_error_prompt; prompt_input("? ");
+@z
+
+431. Don't exit to editor if no input file is at the bottom line
+(Xiaosa Zhang, 03 July 2020)
+@x module 84
+"E": if base_ptr>0 then
+@y
+"E": if base_ptr>0 then if input_stack[base_ptr].name_field>=256 then
+@z
+@x module 85
+if base_ptr>0 then print("E to edit your file,");
+@y
+if base_ptr>0 then if input_stack[base_ptr].name_field>=256 then
+  print("E to edit your file,");
+@z
+
+432. Keep date and time in system variables, use them in opening banner
+(Udo Wermuth, 11 December 2020)
+@x module 241
+Since standard \PASCAL\ cannot provide such information, something special
+is needed. The program here simply specifies July 4, 1776, at noon; but
+users probably want a better approximation to the truth.
+
+@p procedure fix_date_and_time;
+begin time:=12*60; {minutes since midnight}
+day:=4; {fourth day of the month}
+month:=7; {seventh month of the year}
+year:=1776; {Anno Domini}
+@y
+Since standard \PASCAL\ cannot provide such information, something special
+is needed. The program here simply assumes that suitable values appear in
+the global variables \\{sys\_time}, \\{sys\_day}, \\{sys\_month}, and
+\\{sys\_year} (which are initialized to noon on 4 July 1776,
+in case the implementor is careless).
+
+@p procedure fix_date_and_time;
+begin sys_time:=12*60;
+sys_day:=4; sys_month:=7; sys_year:=1776;  {self-evident truths}
+time:=sys_time; {minutes since midnight}
+day:=sys_day; {day of the month}
+month:=sys_month; {month of the year}
+year:=sys_year; {Anno Domini}
+@z
+@x module 246
+@ Of course we had better declare another global variable, if the previous
+routines are going to work.
+
+@<Glob...@>=
+@!old_setting:0..max_selector;
+@y  
+@ Of course we had better declare a few more global variables, if the previous
+routines are going to work.
+
+@<Glob...@>=
+@!old_setting:0..max_selector;
+@!sys_time,@!sys_day,@!sys_month,@!sys_year:integer;
+    {date and time supplied by external system}
+@z
+@x module 536
+print_int(day); print_char(" ");
+months:='JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC';
+for k:=3*month-2 to 3*month do wlog(months[k]);
+print_char(" "); print_int(year); print_char(" ");
+print_two(time div 60); print_char(":"); print_two(time mod 60);
+@y
+print_int(sys_day); print_char(" ");
+months:='JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC';
+for k:=3*sys_month-2 to 3*sys_month do wlog(months[k]);
+print_char(" "); print_int(sys_year); print_char(" ");
+print_two(sys_time div 60); print_char(":"); print_two(sys_time mod 60);
+@z
+
+433. After nine parameters, delete both # and the token that follows
+(Bruno Le Floch, 22 October 2020)
+@x module 473
+label found,done,done1,done2;
+@y
+label found,continue,done,done1,done2;
+@z
+@x module 474
+begin loop begin get_token; {set |cur_cmd|, |cur_chr|, |cur_tok|}
+@y
+begin loop begin continue: get_token; {set |cur_cmd|, |cur_chr|, |cur_tok|}
+@z
+@x module 476
+  help1("I'm going to ignore the # sign you just used."); error;
+@y
+  help2("I'm going to ignore the # sign you just used,")@/
+    ("as well as the token that followed it."); error; goto continue;
+@z
+
+434. Don't accept an implicit left brace after # in macro head
+(Udo Wermuth, 20 May 2020)
+@x module 476
+if cur_cmd=left_brace then
+@y
+if cur_tok<left_brace_limit then
+@z
+
+435. Keep garbage out of the buffer if a |\read| end unexpectedly
+(DRF, 17 February 2018)
+@x module 486
+    align_state:=1000000; error;
+@y
+    align_state:=1000000; limit:=0; error;
+@z
+
+436. Zero out nonexistent chars, to prevent rogue TFM files
+(DRF, 06 October 2020)
+@x module 722
+    math_type(a):=empty;
+@y
+    math_type(a):=empty; cur_i:=null_character;
+@z
+
+437. Don't classify fraction noads as inner noads (DRF, 25 March 2019)
+@x module 761
+fraction_noad: begin t:=inner_noad; s:=fraction_noad_size;
+  end;
+@y
+fraction_noad: s:=fraction_noad_size;
+@z
+
+438. Properly identify tabskip glue when tracing repeated templates
+(Igor Liferenko, 10 January 2020)
+@x module 793
+link(p):=new_glue(glue_ptr(cur_loop));
+@y
+link(p):=new_glue(glue_ptr(cur_loop));
+subtype(link(p)):=tab_skip_code+1;
+@z
+
+439. Use the correct range for local variable hn (DRF, 31 October 2020)
+@x module 892
+@!hn:small_number; {the number of positions occupied in |hc|}
+@y
+@!hn:0..64; {the number of positions occupied in |hc|;
+                                  not always a |small_number|}
+@z
+
+440. Normalize newlinechar when printing the final stats
+(Udo Wermuth, 29 November 2020)
+@x module 1333
+begin @<Finish the extensions@>;
+@y
+begin @<Finish the extensions@>; new_line_char:=-1;
+@z
+@x module 1335
+begin c:=cur_chr;
+@y
+begin c:=cur_chr; if c<>1 then new_line_char:=-1;
+@z
+
+-----------
+999. The absolutely final change (to be made after my death)
+@x module 2
+@d banner=='This is TeX, Version 3.141592653' {printed when \TeX\ starts}
+@y
+@d banner=='This is TeX, Version $\pi$' {printed when \TeX\ starts}
+@z
+When this change is made, the corresponding line should be changed in
+Volume B, and also on page 23 of The TeXbook.
+My last will and testament for TeX is that no further changes be made
+under any circumstances. Improved systems should not be called simply `TeX';
+that name, unqualified, should refer only to the program for which I have
+taken personal responsibility.  -- Don Knuth
+
+* Possibly nice ideas that will not be implemented
+
+. classes of marks analogous to classes of insertions
+
+. \showcontext to show the current location without stopping for error
+
+. \show commands to be less like errors
+
+. \everyeof to insert tokens before an \input file ends
+  (strange example: \everyeof{\noexpand} will allow things
+    like \xdef\a{\input foo}!)
+
+. generalize \leftskip and \rightskip to token lists (problems with
+   displayed math then)
+
+. generalize \widowline and \clubline to go further into a paragraph
+
+. \lastbox to remove and box a charnode if one is there
+
+. \lastbox to set a new quantity \lastboxshift, to preserve info now lost
+
+. \posttolerance for third pass of line breaking
+
+* Design errors that are too late to fix
+
+. additional parameters should be in symbol fonts to govern the space between
+  rules and text in \over, \sqrt, etc.
+
+. multilingual typesetting doesn't work properly when the \lccode changes
+  within a paragraph
+
+. large accents cannot be brought close to small letters in math mode
+
+. \hyphenation is not sensitive to \language
+
+* Bad ideas that will not be implemented
+
+. several people want to be able to remove arbitrary elements of lists,
+   but that must never be done because some of those elements (e.g. kerns
+   for accents) depend on floating point arithmetic
+
+. if anybody wants letter spacing desperately they should put it in their own
+   private version (e.g. generalize the hpack routine) and NOT call it TeX.
diff --git a/Master/tlpkg/bin/tlpkg-ctan-check b/Master/tlpkg/bin/tlpkg-ctan-check
index 2ca7d79fd45..5ec3946c43f 100755
--- a/Master/tlpkg/bin/tlpkg-ctan-check
+++ b/Master/tlpkg/bin/tlpkg-ctan-check
@@ -415,7 +415,7 @@ my @TLP_working = qw(
     kblocks kdgdocs kerkis kerntest ketcindy
     keycommand keyfloat keyindex keyreader keystroke
     keyval2e keyvaltable kix kixfont
-    knitting knittingpattern knowledge knuth knuth-lib knuth-local
+    knitting knittingpattern knowledge knuth knuth-errata knuth-lib knuth-local
     koma-moderncvclassic koma-script koma-script-examples koma-script-sfs
     komacv komacv-rg kotex-oblivoir kotex-plain kotex-utf kotex-utils
     kpfonts kpfonts-otf ksfh_nat ksp-thesis
@@ -433,7 +433,7 @@ my @TLP_working = qw(
     latex-git-log latex-graphics-companion latex-graphics-dev
     latex-make latex-mr latex-notes-zh-cn
     latex-papersize latex-refsheet
-    latex-tds latex-tools-dev latex-uni8
+    latex-tools-dev latex-uni8
     latex-veryshortguide latex-via-exemplos latex-web-companion
     latex2e-help-texinfo latex2e-help-texinfo-fr
     latex2e-help-texinfo-spanish latex2man latex2nemeth
diff --git a/Master/tlpkg/bin/tlpkginfo b/Master/tlpkg/bin/tlpkginfo
index 7ab4ba42658..15955427bf7 100755
--- a/Master/tlpkg/bin/tlpkginfo
+++ b/Master/tlpkg/bin/tlpkginfo
@@ -78,12 +78,6 @@ sub ctaninfo {
        hacm inriafonts imtekda mathdesign sdaps tufte-latex xassoccnt),
     );
   
-  # special packages from latex-tds project; used by prepare()
-  $latex_tds_pkgs  = "latex-tds";
-#  $latex_tds_pkgs .= "|psnfss"; # amsmath|cyrillic|graphics|latex|tools on own
-  $latex_tds_pkgs .= "|knuth";  # other
-  $latex_tds_dir = "$CTAN/macros/latex/contrib/latex-tds";
-  
   # the CJK material is split into several packages.
   $cjk_pkgs = "bin-(cjk|ttf)utils|dnp|(|garuda-|norasi-)c90";
 
@@ -432,9 +426,6 @@ sub prepare {
   } elsif ($pkg eq "latex") {
     $tds_path = "$CTAN/install/macros/latex/latex-base.tds.zip";
 
-  # ...and except for files in latex-tds...
-  } elsif ($pkg =~ /^($latex_tds_pkgs)$/) {
-    $tds_path = "$latex_tds_dir/$pkg.tds.zip";
   }
 
   my $tds_path_ok = -s $tds_path ? 1 : 0;
diff --git a/Master/tlpkg/tlpsrc/collection-langenglish.tlpsrc b/Master/tlpkg/tlpsrc/collection-langenglish.tlpsrc
index 62c29b88d83..55eb18ecabe 100644
--- a/Master/tlpkg/tlpsrc/collection-langenglish.tlpsrc
+++ b/Master/tlpkg/tlpsrc/collection-langenglish.tlpsrc
@@ -27,6 +27,7 @@ depend happy4th
 depend impatient
 depend intro-scientific
 depend knuth
+depend knuth-errata
 depend l2tabu-english
 depend latex-brochure
 depend latex-course
diff --git a/Master/tlpkg/tlpsrc/knuth-errata.tlpsrc b/Master/tlpkg/tlpsrc/knuth-errata.tlpsrc
new file mode 100644
index 00000000000..e69de29bb2d
--- /dev/null
+++ b/Master/tlpkg/tlpsrc/knuth-errata.tlpsrc
author	Karl Berry <karl@freefriends.org>	2021-03-08 18:32:57 +0000
committer	Karl Berry <karl@freefriends.org>	2021-03-08 18:32:57 +0000
commit	b8bbb5c4096ec141403ff5e06e55c25eb7f3c805 (patch)
tree	64c2b4b1b84765421aba98966cb8a4d9a297015c /Master
parent	a4aa2281f58a777d7188ff716f0b38e78098e480 (diff)