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diff --git a/info/digests/tex-implementors/036 b/info/digests/tex-implementors/036 new file mode 100644 index 0000000000..1a9a31fa85 --- /dev/null +++ b/info/digests/tex-implementors/036 @@ -0,0 +1,540 @@ +Date: 14 March 91 Message No: 036 + +To: TeX implementors and distributors + +From: Barbara Beeton + +Subject: Messages from DEK, part 1 + + +The latest package of marked-up messages from DEK was postmarked +15 January 92. It contained 10 checks, including two for actual bugs. +Unfortunately, other matters have conspired to delay my forwarding of +all this material, and I apologize. (I don't suppose anyone out there +would like to be a TUGboat production assistant? Or has lots of +experience in moving from one office to another with less shelf space +without losing track of anything? Didn't think so, somehow.) + +As some of you may know, DEK was awarded an honorary doctorate by the +Royal Institute of Technology in Stockholm last November. At that time, +some bug reports and other questions were apparently given to him in +person, and changes have been delayed as explained in this note which +accompanied the package: + + Barbara: Many thanks for this compilation! I will not however be + ready to update the sources until February because I mistakenly + put some things recd in Sweden into the wrong box and they are + currently being shipped via _sea_ _mail_. + I have gone through this material but will hold off updating the + master sources until I've gotten through some other things sent + to me in Stockholm from Poland, some of which may be extremely + important + +I have just finished checking the /tex area at labrea. There are no new +files in the errata directory, and as these are usually the first to be +installed, I assume that the main update has not yet been made. + + +######################################################################## + +Contents: + [ part 1 ] + >>> responses to DEK Sep 26 package + >>> DEK's alpha test, TeX 3.14a + >>> TeXbook errata + >>> inconsistent ligature/kerning behavior + >>> inconsistent expansion of \string, etc.; \newlinechar + >>> \halign + box assignment within displays + >>> positive/negative xn_over_d, tex.web section 107 + >>> DRF's "remaining comments" + >>> suggestion -- additional tracing facilities for \if* + >>> DEK's "local" change files, not at labrea + [ part 2 ] + >>> glue_ratio overflow + >>> \TeX logo; some problems with \loop + >>> cedilla accent macro in plain.tex + >>> missing \mathsurround in plain.tex + >>> \arrowvert code, plain.tex + >>> MF -- bugs or features? (also, some ACP errata) + >>> MFbook errata + >>> WEAVE -- Peter Breitenlohner + >>> WEAVE -- Brian {Hamilton Kelly} + [ sent separately ] + >>> Barry Smith, |history| variable in TeX.WEB + >>> Chris Rowley, two items: \fontdimen2 and marks + +************************************************************************ + +>>> responses to DEK Sep 26 package + +Date: Mon, 23 Dec 91 13:23:58 +0100 +From: Eberhard Mattes <mattes@azu.informatik.uni-stuttgart.de> +Subject: Backenfisch, tex.web + +> [ dek: should i have used `backenfisch' instead? ] + +Maybe deleting `compound' on p. 96 would be better since I have found +no word with ck hyphenated k-k *because* it is a compound word. +(Of course there are words containing tt hyphenated tt-t *because* +they are compound words.) + + [ dek: + point well taken ... but I wasn't serious and i _did_ delete + `compound' in September as he requested + ] + --- + +In tex.web, there's a @^system dependencies@> missing for the line + [ dek: \S798 ] + +if n>max_quarterword then confusion("256 spans"); {this can happen, but won't} + ^^^ + This is system-dependent. + [ dek: $2.56 ] + +Yours, + Eberhard Mattes (mattes@azu.informatik.uni-stuttgart.de) + +<<< end responses to DEK Sep 26 package + +************************************************************************ + +>>> DEK's alpha test, TeX 3.14a + +Date: Tue 24 Sep 91 11:22:21-EST +From: bbeeton <BNB@MATH.AMS.COM> +To: cet1%phx.cam.ac.uk@nsfnet-relay.ac.uk, + tex%uk.ac.cranfield.rmcs@nsfnet-relay.ac.uk, pzf5hz@ruipc1e.Bitnet +Subject: message from dek -- tex alpha version 3.14a + +chris, brian, and frank, +you are hereby deputized to follow dek's instructions and test out +the new version. [ ... ] +i won't forward this information to anyone else [for at least two +weeks], and you probably should be discreet about it too. thanks. +cheers. -- bb + -------------------- +Date: Fri, 20 Sep 91 12:50:54 -0700 +Subject: note from Don + + [ copy of message from dek ] + ------- +Date: Thu, 26 SEP 91 22:31:01 BST +From: TEX@rmcs.cranfield.ac.uk +Reply-to: Brian {Hamilton Kelly} <TeX@rmcs.cranfield.ac.uk> +Subject: RE: message from dek -- tex alpha version 3.14a + +In message <685725741.0.BNB@MATH.AMS.COM> +of Tue 24 Sep 91 11:22:21-EST, bbeeton <BNB@com.AMS.MATH> wrote: + +> chris, brian, and frank, +> you are hereby deputized to follow dek's instructions ... +> ... (i will take care of the envelope of "comments and checks" + ^ + (Would I spell this cheques? :-) +> as soon as i can after i get back to providence.) + +Well, I've collected the new files (I *love* the README!!), modified my +change file to accommodate the new banner and a few of the +|slow_print|s, and built 3.14a. It's great!! Fixes my problem with +hyphenation vs. boundary ligatures perfectly. And what an elegant +solution: I'd expected the fix to be complicated, but it just requires +one simple global and the odd preservation of context. + +> Date: Fri, 20 Sep 91 12:50:54 -0700 +> Subject: note from Don +> +> Meanwhile, there's some more "immediate" news. I've prepared an +> alpha-test version of TeX, called version 3.14a. Before I release +> it officially, I'd like CET1 and Brian Hamilton-Kelly and maybe +> Frank Mittelbach [and anybody else you think best, but I don't really +> want this version to proliferate] to try it. There are two changes, +> one to cure the anomaly Frank noticed about \newlinechar acting +> differently wrt \write and \message [and other similar glitches I +> then noticed myself], the other to fix I hope the problem Brian was +> having with Greek. I'm reluctant to let the version number converge to +> \pi too quickly, so I would at least like to have Brian accumulate +> some experience with his Greek tests before putting this out widely. +> Of course anybody is free to use it at their own risk. + +Be warned, however, that so far I've only tested it against the input +that caused me problems back in April. I'll try to do some more +thorough testing in the near future. + + [ dek: + Certainly hope you did by now -- I need more reassurance than + a single test + ] + +> The files tex.web and tex82.bug have been moved to labrea.stanford.edu +> where they are accessible via anonymous ftp. After logging in, +> connect to directory alpha (which is for alpha-test software). +> I forgot to copy the trip test files; if they are desperately needed, +> I could bring them in from home. + +I haven't TRIPped the new TeX for this reason. The interesting thing +would be if TRIP were extended to check the new ligature/hyphenation +code: I expect that, with DEK's customary thoroughness, he'll have done +this, so look forward to applying the tests myself when 3.14a emerges as +3.141. + + [ dek: + Actually my customary thoroughness is becoming less customary + ] + +> So, next week you'll get my letter explaining all! Meanwhile, a +> lookahead: I'll be in Sweden during November and December (thanks to +> some good words from Roswitha, I'll getting an honorary degree +> there!), and I plan to make the next official update to TeX sources +> early in January. By then, this version 3.14a should be checked out, +> and I can release it as version 3.141. + +Whilst you're talking to DEK, barbara, what response did he give to that +d..d problem of Weave failing to wrap correctly when processing a TeX +comment? I have a horrible suspicion in my mind that he's already said +something to the effect that he edited it manually! Or am I imagining +that horror? My fix works very well and doesn't have any bugs that I +can see, so why doesn't he adopt it? + +Brian HK + ------- +Date: Sun, 29 Sep 91 00:56:57 BST +From: Chris Thompson <CET1@phoenix.cambridge.ac.uk> +To: Barbara Beeton <BNB@MATH.AMS.com> +Cc: Brian {Hamilton Kelly} <tex@rmcs.cranfield.ac.uk>, + Frank Mittelbach <pzf5hz@ruipc1e.bitnet> +Subject: Re: [message from dek -- tex alpha version 3.14a] + +Barbara, Brian, Frank, + + I have fetched and compiled TeX 3.14a. Unfortunately, change 397 +seems to have bugs. Try the following input: + + % TeX 3.14a test + \pretolerance=-1 + \ Respectively.\par + \showboxbreadth=255 \showboxdepth=255 \showlists + \bye + +and compare the log files for 3.14 and 3.14a. That for 3.14a has an +extra kern in between the "-ly" and the ".": + + .\tenrm e + .\tenrm l + .\tenrm y + .\kern-0.83334 \ This kern has been doubled by the + .\kern-0.83334 / automatic hyphentaion algorithm. + .\tenrm . + .\penalty 10000 + + [ dek: + well, this made me feel very sick, but I sure am thankful to + Chris for finding it. + $10.24 + ] + +I discovered this while checking that 'webman.tex' generated the same +DVI file (except for date stamp), which is part of my standard paranoia +suite. There were two discrepancies of the above type in the very first +paragraph... but the rest of the document produced no more! + + [ dek: + I think probably the _old_ 3.0 would also produce double kerns + in cases where kern was specified before right boundary character + by font designer [e.g. to kern after f at end of word] + + While studying this I found another mistake in my code from + September. But I think the basic idea was sound, only the + execution was faulty. + + Still I guess I should try another alpha test with "3.14b"? + ] + +Brian & Frank: can you confirm this effect? + +Chris Thompson +Cambridge University Computing Service +JANET: cet1@uk.ac.cam.phx +Internet: cet1@phx.cam.ac.uk + ------- +Date: Mon, 30 SEP 91 15:46:17 BST +Reply-to: Brian {Hamilton Kelly} <TeX@rmcs.cranfield.ac.uk> +From: TEX@rmcs.cranfield.ac.uk +Subject: Re: [message from dek -- tex alpha version 3.14a] + +In message <A4912BE187A67A40@UK.AC.CAMBRIDGE.PHOENIX> of Sun, 29 Sep 91 +00:56:57 BST, Chris Thompson <CET1@UK.AC.CAMBRIDGE.PHOENIX> wrote: + +> Barbara, Brian, Frank, +> +> I have fetched and compiled TeX 3.14a. Unfortunately, change 397 +> seems to have bugs. [ ... ] +> +> and compare the log files for 3.14 and 3.14a. That for 3.14a has an +> extra kern in between the "-ly" and the ".": +> +> .\tenrm e +> .\tenrm l +> .\tenrm y +> .\kern-0.83334 \ This kern has been doubled by the +> .\kern-0.83334 / automatic hyphentaion algorithm. +> .\tenrm . +> .\penalty 10000 +> +> [ ... ] +> +> Brian & Frank: can you confirm this effect? + +I have repeated Chris' experiment, and can confirm that 3.14a does +indeed double the kern. Oh dear... + +The odd thing is that I compared the outputs resulting from running +DVItype on the DVI outputs of my Greek test, and saw only the expected +change from medial sigma to terminal sigma (with relevant horizontal +positioning changes). But I may have missed other horizontal changes +due to this bug: I've thrown the printout away again by now, +unfortunately! + +Brian + +<<< end DEK's alpha test, TeX 3.14a + +************************************************************************ + +>>> TeXbook errata + +Date: Tue, 19 Nov 91 16:05:02 GMT +From: Chris Thompson <CET1@phoenix.cambridge.ac.uk> +Subject: TeXbook p.178 bug report + + Here is another TeXbook bugette report by Robert Hunt. I suppose it is +right in theory, unless it comes under the "deliberate lie" clause. Anyway, +perhaps you would like to have someone else vet it: I am getting to the stage +with Robert's bug reports that I just wish he would shut up! He seems happy +with the latest p.377 fix, by the way. + + ----------------------------------------------------------------------- +REH10 15 Nov 1991 16.49 +Very minor mistake on p.178 of the TeXbook: it claims that using \phantom{...} +in a maths formula always produces the same spacing (vertical and horizontal) +as just {...}; but of course this isn't true as \phantom can't tell whether the +current maths style is cramped or not, so \phantom{U^2} will produce different +vertical spacing in cramped style compared with what {U^2} would produce. I +don't think this is particularly worth worrying about, but it's always annoyed +me that \mathchoice doesn't distinguish between (say) T and T'. + ----------------------------------------------------------------------- + + [ dek: + $2.56 + I'm going to put the apology on page 360 because the truth would + interfere with the exposition on p 178 + ] + +Chris Thompson + + ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + +Date: Tue, 3 Dec 91 15:13:01 MST +From: Nelson H. F. Beebe <beebe@math.utah.edu> +Subject: Possible bug in TeXbook, p.270 + +Last night, while studying to TeXbook to better understand TeX's rules +for when spaces are significant, I found what I believe is a small +error in the TeXbook. I checked errata files errata.one .. errata.six +without finding this error already logged. + +The TeXbook, p.270, gives BNF rules for the grammar of dimensions. +>From this grammar, one concludes from the rules (pulled from +texman.tex) + +<optional {\tt true}>\is[true]\alt<empty> + +<unit of measure>\is<optional spaces><internal unit> + \alt<optional {\tt true}><physical unit><one optional space> + +<normal dimen>\is<internal dimen>\alt<factor><unit of measure> + +<factor>\is<normal integer>\alt<decimal constant> + +<decimal constant>\is|.|$_{12}$\alt|,|$_{12}$ + \alt<digit><decimal constant> + \alt<decimal constant><digit> + +that "123 truept" is illegal input, since no space may precede the +word true according to the grammar. + +Nevertheless, TeX the program happily accepts such space: + +This is TeX, C Version 3.14 +**\relax + +*\dimen0 = 12345 true pt + + [ dek: + see the \P on p 268 that begins `We shall use a special + convention for keywords'. _true_ is a keyword + ] + +*\showthe\dimen0 +> 12345.0pt. +<*> \showthe\dimen0 + +? + +I believe that TeX the program is correct, and is consistent with its +permitting optional space before non-true dimensions. + +This suggests that the TeXbook should have the rule + +<unit of measure>\is<optional spaces><internal unit> + \alt<optional {\tt true}><physical unit><one optional space> + +changed to + +<unit of measure>\is<optional spaces><internal unit> + \alt<optional spaces><optional {\tt true}><physical unit><one optional space> + +I'm assuming that AB|CDE is to be parsed as (AB)|(CDE) (the +conventional interpretation in BNF grammars), rather than A(B|C)DE; +the latter would not make sense here anyway. + +======================================================================== +Nelson H.F. Beebe +Center for Scientific Computing +Department of Mathematics +220 South Physics Building +University of Utah +Salt Lake City, UT 84112 +USA + Tel: (801) 581-5254 + FAX: (801) 581-4148 + Internet: beebe@math.utah.edu +======================================================================== + +<<< end TeXbook errata + +************************************************************************ + +>>> inconsistent ligature/kerning behavior + +Date: Wed, 25 Sep 91 13:13:55 +0200 +From: Bernd Raichle <raichle@azu.informatik.uni-stuttgart.de> +Subject: Bug in TeX's ligature builder?! (No, it's documented.) + +In a letter to DEK in November 1989 (i.e., before TeX 3.0; appeared in +TeXhax 90, Issue 5) Frank Mittelbach summarized some requirements of a +new TeX version. For example, he mentioned manipulations of the +"Ligatures and kerning tables" and the need to "Reconsider paragraphs +after page-breaking". Other users had and have similar wishes and +requirements. + +But nobody mentioned a bug, or better --- because this "bug" is +documented in the TeXbook --- the inconsistent and (for the beginner) +mysterious behaviour when TeX builds ligatures and inserts kerning. + +Try the following in plain TeX and look at the output. I have used +the fl-ligature as an example. (TeX's behaviour for kerning between +two characters is exactly the same.) + + ------------------------------ CUT ------------------------------ +\hsize=5cm % linebreak for more than three words +\hyphenation{Au-flage}% for demonstration (correct german is Auf-la-ge) + +Auflage\par % (1) show `fl' ligature +Auf{}lage Auf\relax lage\par % (2) simple way to avoid the ligature + +\pretolerance=10000 % no second pass +Auf{}lage +Auf{}lage Auf{}lage Auf{}lage Auf{}lage\par % (3) no ligatures + +\pretolerance=-1 % force second pass +Auf{}lage % no(!) ligature, because there's no preceding glue +Auf{}lage Auf{}lage Auf{}lage Auf{}lage\par % (4) ligatures + +Auf{}lage % (5) no(!) ligature, there's no preceding glue +Auf\kern0pt lage % no lig, explicit kern +Auf\/lage % no lig, explicit kern +$\rm Auflage$ % example of ligature in math mode +$\rm Auf{}lage$ % no lig, in math mode +\hbox{Auf{}lage} % no lig, in packed hbox +Auf{}lage\vrule width0pt\ % no lig, followed by a rule node +Auf{}lage\kern0ptAuf{}lage % 1st ligature, 2nd no ligature +Auf{}lage\par % ligature +\bye + ------------------------------ CUT ------------------------------ + +Example (1) shows the normal fl ligature, in example (2) I suppress +the ligature with an empty group (see TeXbook, exercise 5.1 and +answer) or a \relax (both are non-character tokens). + +In example (3) I use empty groups to suppress the ligatures. The +same(!) input paragraph in example (4) contains ligatures. The only +and very important difference between (3) and (4) is the value of +\pretolerance. (Note that the first word in (4) has no fl-ligature!) + +Example (5) gives a quick overview of TeX's behaviour, when the same +word (= the same input!) is used in a different context. You can +think of other examples: hbox the word... and unhbox it. Try the same +with the ''-ligature (i.e. compare '' with '{}'), etc. + + +Very short explanation of this behaviour: when TeX is in hmode, +ligatures and kernings are build out of the (current input) token +list. Non-character tokens (like { or \relax) influence ligatures and +kerning. + +When TeX is in math mode or after hyphenation is done in the second +pass of the line_break algorithm, ligatures and kernings are build out +of the node list representing the current paragraph (or math list). +This node list doesn't contain representations for tokens like { or +\relax anymore. Because not all parts of the node list are tried for +hyphenation, not all of the supressed ligatures are reconstituted. + + +TeX has a powerful linebreak algorithm, a powerful hyphenation +capability and powerful ligature and kerning tables. +But the connection between them shows IMHO design bugs, if you want to +use them and expect the same output from the same input. + + [ dek: + This is unfortunate but known and I decided long ago that + the cure would be worse than the disease. + ] + +Comments, etc. ...?? (... are expected!!) + + -bernd + +PS: I have ideas how to make ligatures/kerning more consistent. + But the result, after the necessary changes (in a few places) + are applied, is a "TeX" which fails the Trip-Test. + + __________________________________________________________________________ + Bernd Raichle, Student der Universit"at Stuttgart | "Le langage est source + privat: Stettener Str. 73, D-W-7300 Esslingen | de malentendus" + email: raichle@azu.informatik.uni-stuttgart.de | (A. de Saint-Exupery) + +<<< end inconsistent ligature/kerning behavior + + +######################################################################## + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% Character code reference +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% Upper case letters: ABCDEFGHIJKLMNOPQRSTUVWXYZ +% Lower case letters: abcdefghijklmnopqrstuvwxyz +% Digits: 0123456789 +% Square, curly, angle braces, parentheses: [] {} <> () +% Backslash, slash, vertical bar: \ / | +% Punctuation: . ? ! , : ; +% Underscore, hyphen, equals sign: _ - = +% Quotes--right left double: ' ` " +%"at", "number" "dollar", "percent", "and": @ # $ % & +% "hat", "star", "plus", "tilde": ^ * + ~ +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +[ end of message 036 ] + |