CTAN sync 202402010300

1 files changed, 377 insertions, 77 deletions

diff --git a/support/splint/tex/limbo.sty b/support/splint/tex/limbo.sty
index c810cd55da..91ec2c973f 100644
--- a/support/splint/tex/limbo.sty
+++ b/support/splint/tex/limbo.sty
@@ -1,4 +1,4 @@
-% Copyright 2012-2020, Alexander Shibakov
+% Copyright 2012-2024, Alexander Shibakov
 % This file is part of SPLinT
 %
 % SPLinT is free software: you can redistribute it and/or modify
@@ -164,6 +164,11 @@
 \font\sevenfrak=eufm7
 \font\sixfrak=eufm6
 
+\font\nineidss=idssbx9
+\font\eightidss=idssbx8
+\font\sevenidss=idssbx7
+\font\sixidss=idssbx6
+
 \font\hv=phvr
 
 \font\dings=pzdr
@@ -230,7 +235,7 @@
   \def\ssfb{\fam\ssfam\tenssb}%
   \def\ssfbn{\fam\ssbnfam\tenssb}%
   \textfont\ssbnfam=\tenssn\scriptfont\ssfam=\sevenssn
-  \textfont\ttfam=\tentt
+  \textfont\ttfam=\tentt\scriptfont\ttfam=\seventt
   \fam\ttfam\tentt \ttglue=.5em plus.25em minus.15em
   \def\Bbb{\fam\msbmfam\tenmsbm}%
   \textfont\msbmfam=\tenmsbm\scriptfont\msbmfam=\sevenmsbm \scriptscriptfont\msbmfam=\fivemsbm
@@ -243,6 +248,7 @@
   \let\mc=\ninerm
   \let\cyr=\tencyr
   \let\big=\tenbig
+  \let\idss=\eightidss
   \setbox\strutbox=\hbox{\vrule height8.5pt depth3.5pt width0pt}%
   \let\sscmd\sevenpoint
   \normalbaselines\rm}
@@ -280,7 +286,7 @@
   %no room for another font family
   \def\ssfbn{\fam\ssbnfam\ninessn}%
   \textfont\ssbnfam=\ninessn\scriptfont\ssbnfam=\sixssn
-  \textfont\ttfam=\ninett
+  \textfont\ttfam=\ninett\scriptfont\ttfam=\sixtt
   \fam\ttfam\ninett \ttglue=.5em plus.25em minus.15em
   \def\Bbb{\fam\msbmfam\ninemsbm}%
   \textfont\msbmfam=\ninemsbm\scriptfont\msbmfam=\sixmsbm \scriptscriptfont\msbmfam=\fivemsbm
@@ -293,6 +299,7 @@
   \let\mc=\eightrm
   \let\cyr=\ninecyr
   \let\big=\ninebig
+  \let\idss=\sevenidss
   \setbox\strutbox=\hbox{\vrule height8pt depth3pt width0pt}%
   \let\sscmd\sixpoint
   \normalbaselines\rm}
@@ -340,6 +347,7 @@
   \let\mc=\sevenrm
   \let\cyr=\eightcyr
   \let\big=\eightbig
+  \let\idss=\sixidss
   \setbox\strutbox=\hbox{\vrule height7pt depth2pt width0pt}%
   \let\sscmd\sixpoint
   \normalbaselines\rm}
@@ -381,6 +389,7 @@
   \let\sci=\sixit
   \let\mc=\sixrm
   \let\big=\sevenbig
+  \let\idss=\sixidss
   \setbox\strutbox=\hbox{\vrule height6pt depth2pt width0pt}%
   \normalbaselines\rm}
 
@@ -421,6 +430,7 @@
   \let\sci=\sixit
   \let\mc=\sixrm
   \let\big=\sixbig
+  \let\idss=\sixidss
   \setbox\strutbox=\hbox{\vrule height5.5pt depth1.5pt width0pt}%
   \normalbaselines\rm}
 
@@ -591,7 +601,8 @@
 
 % demo code display
 % **H will produce a `|', **K can be used as an escape character, **L and **N 
-% can be used i place of left and right braces to provide some control
+% can be used in place of left and right braces to provide some control **C is
+% a comment character when needed
 
 {\catcode`\ =\active\gdef {\phantom{\char"20\relax}}\catcode`\^^H=\active\gdef^^H{\yl}}%
 
@@ -607,7 +618,7 @@
   \catcode`\^=\active\democodelc=0 \catcode`\*=7
   \chardef\*=`\*%
   \catcode`\^^H=\active % ^^H
-  \catcode`\^^K=0 \catcode`\^^L=1 \catcode`\^^N=2
+  \catcode`\^^K=0 \catcode`\^^L=1 \catcode`\^^N=2 \catcode`\^^C=14 
   \tabskip=0pt plus 1 fill 
   \halign \demoastyle\bgroup\linenoup\hskip\demomargin ##\hfil\hskip\demomargin%
   \ifnumberlines{\sevenrm\paddednumber\democodelc}\fi\cr%
@@ -615,6 +626,10 @@
 
 \def\enddemo{\egroup\egroup\medskip\noindent}
 
+% referencing lines from the demo code
+\def\dlbl#1{\expandafter\xdef\csname lncnt_#1\endcsname{\the\democodelc}}%
+\def\dref#1{\csname lncnt_#1\endcsname}%
+
 \newskip\demomargin
 \demomargin=3em
 
@@ -645,7 +660,8 @@
   \epsfbox{#1.eps}\fi
 }
 
-\let\yl| % to use in \TeX\ mode instead of `|'
+\let\yl|   % to use in \TeX\ mode instead of `|'
+\def\vl{|} % same as above but expandable
 \def\greaterthan{>} % CTANGLE always leaves a space after `>' in the output which interferes with some macros
 
 % redefinitions of various CWEB macros;
@@ -760,7 +776,7 @@
     \def\stripprefix##1>{}\def\gtitletoks{#3}%
     \edef\gtitletoks{\expandafter\stripprefix\meaning\gtitletoks}%
     \edef\next{\write\cont{%\noexpand\noexpand\noexpand\eatone{\noexpand\meaning\noexpand\ZZ}%
-                \noexpand\noexpand\noexpand % AS this is a (sort of) bug in cwebmac.tex
+                \noexpand\noexpand\noexpand % AS: this is a (sort of a) bug in cwebmac.tex
                                             % as long as the index is output (i.e. ...\eject) 
                                             % before all the sections this is unnecessary
                                             % uncomment the line after the brace to see what \ZZ
@@ -800,46 +816,74 @@
     \ifpdftex\expandafter\xdef\csname curr#1\endcsname{\secno}%
       \ifnum#1>0\countB=#1 \advance\countB by-1
         \advancenumber{chunk\the\countB.\expnumber{curr\the\countB}}\fi\fi
-    \ifpdf\special{pdf: outline #1 << /Title (\the\toksE) /Dest
-      [ @thispage /FitH @ypos ] >>}\fi
+    % drop support for pdf specials: AS
     \ifon\startsection{\ttl#3}\smallskip\noindent\ignorespaces} 
 
 \outer\def\chapterN#1#2#3.{% beginning of starred section in `book' mode
     \ifacro{\toksF={}\makeoutlinetoks#3\outlinedone\outlinedone}\fi
     \gdepth=#1\gtitle={#3}\MN{#2}%
-    \ifon
-        \ifnum#1<\tw@
-            \vfil\eject % force page break for chapters and major subsections
-            \ifodd\pageno
-            \else
-                \null\vfill\eject
-            \fi
-        \else
-            \vskip0pt plus 3.5\baselineskip
-            \penalty-100
-            \vskip0pt plus -3.5\baselineskip
-            \vskip\intersecskip % no forced page break
-        \fi
-    \fi
-    \message{*\secno} % progress report
+    \ifon\stsecchappreseparator{#1}\fi % before the title
+    \message{*\secno}% progress report
     \def\stripprefix##1>{}\def\gtitletoks{#3}%
     \edef\gtitletoks{\expandafter\stripprefix\meaning\gtitletoks}%
-    \edef\next{\write\cont{%\noexpand\noexpand\noexpand\eatone{\noexpand\meaning\noexpand\ZZ}%
-                \noexpand\noexpand\noexpand % AS this is a (sort of) bug in cwebmac.tex
-                                            % as long as the index is output (i.e. ...\eject) 
-                                            % before all the sections this is unnecessary
-                                            % uncomment the line after the brace to see what \ZZ
-                                            % expands to in case of weird errors
-                \ZZ{\gtitletoks}{#1}{\secno}% write to contents file
-     {\noexpand\the\pageno}{\the\toksE}}}\next % \ZZ{title}{depth}{sec}{page}{ss}
-    \ifpdftex\expandafter\xdef\csname curr#1\endcsname{\secno}%
-      \ifnum#1>0\countB=#1 \advance\countB by-1
-        \advancenumber{chunk\the\countB.\expnumber{curr\the\countB}}\fi\fi
-    \ifpdf\special{pdf: outline #1 << /Title (\the\toksE) /Dest
-      [ @thispage /FitH @ypos ] >>}\fi
+    \edef\next{%
+        \write\cont{%\noexpand\noexpand\noexpand\eatone{\noexpand\meaning\noexpand\ZZ}%
+        \noexpand\noexpand\noexpand % AS this is a (sort of) bug in cwebmac.tex
+                                    % as long as the index is output (i.e. ...\eject) 
+                                    % before all the sections this is unnecessary
+                                    % uncomment the line after the brace to see what \ZZ
+                                    % expands to in case of weird errors
+        \ZZ{\gtitletoks}{#1}{\secno}{\noexpand\the\pageno}{\the\toksE}% \ZZ{title}{depth}{sec}{page}{ss}
+    }}\next % write to contents file
+    \ifpdftex
+        \expandafter\xdef\csname curr#1\endcsname{\secno}%
+        \ifnum#1=\z@
+            \countB=#1 \advance\countB by\@ne
+            \expandafter\xdef\csname curr\the\countB\endcsname{\secno}%
+            \advance\countB by\@ne
+            \expandafter\xdef\csname curr\the\countB\endcsname{\secno}%
+            \advance\countB by\@ne
+            \expandafter\xdef\csname curr\the\countB\endcsname{\secno}%
+        \fi % allow subsection depth to jump up to 3 levels after a chapter: AS
+        \ifnum#1>0\countB=#1 \advance\countB by-1
+            %\message{#3::chunk\the\countB.\expnumber{curr\the\countB}::\expnumber{chunk\the\countB.\expnumber{curr\the\countB}}}%
+            \advancenumber{chunk\the\countB.\expnumber{curr\the\countB}}%
+        \fi
+    \fi
+    % drop support for pdf specials: AS
     \ifon\stsecchap{#1}{#3}\ignorespaces
 }
 
+\def\writebookmarkline#1#2#3#4#5{{% the scheme for bookmarks is rather fragile
+                                  % the proper implementation must involve a stack: AS
+    \let\(=\let \let\)=\let \let\[=\let \let\]=\let \let\/=\let
+    \edef\depth{\expnumber{chunk#2.#3}}%
+    \ifnum\depth=\z@ % allow subsection depth to jump up to 3 levels: AS
+        \countB=#2 \advance\countB\@ne
+        \edef\depth{\expnumber{chunk\the\countB.#3}}%
+        \ifnum\depth=\z@
+            \advance\countB\@ne
+            \edef\depth{\expnumber{chunk\the\countB.#3}}%
+        \fi
+    \fi
+    %\message{bookmark for #5::depth:\depth::#2.#3}%
+    \pdfoutline goto num #3 count -\depth {#5}}}
+
+\def\stsecchappreseparator#1{% separator between the end of the previous section and the current one
+    \ifnum#1<\tw@
+        \vfil\eject % force page break for chapters and major subsections
+        \ifodd\pageno
+        \else
+            \null\vfill\eject
+        \fi
+    \else
+        \vskip0pt plus 3.5\baselineskip
+        \penalty-100
+        \vskip0pt plus -3.5\baselineskip
+        \vskip\intersecskip % no forced page break
+    \fi
+}
+
 \def\stsecchap#1#2{\rightskip=0pt % get out of C mode (cf. \B)
     \sfcode`;=1500 \pretolerance 200 \hyphenpenalty 50 \exhyphenpenalty 50
 %
@@ -891,7 +935,7 @@
 
 \newif\ifchapterhead
 
-% make page and sectoin number hang in the margins; \quad is chosen to
+% make page and section number hang in the margins; \quad is chosen to
 % be consistent with section appearance; the page numbers are printed
 % in old-style numerals;
 
@@ -901,7 +945,7 @@
     \else
         \termindexfalse\headertrue\llap{\mainfont\oldstyle\the\pageno\tentitle\quad}%
         \eightpoint\rm\grouptitle\hfill\title
-        \rlap{\tentitle\quad\tenpoint$^{\hbox{\sevenrm\topsecno}}_{\hbox{\sevenrm\botsecno}}$}%
+        \rlap{\tentitle\quad\secrangedisplay}%
     \fi
 } % top line on left-hand pages
 
@@ -909,23 +953,19 @@
     \ifchapterhead
         \hfil
     \else
-        \termindexfalse\headertrue\llap{\tenpoint$^{\hbox{\sevenrm\topsecno}}_{\hbox{\sevenrm\botsecno}}$\tentitle\quad}% 
+        \termindexfalse\headertrue\llap{\secrangedisplay\tentitle\quad}% 
         \eightpoint\rm\title\hfill\grouptitle
         \rlap{\tentitle\quad\mainfont\oldstyle\the\pageno}%
     \fi
 } % top line on right-hand pages
 
+\def\secrangedisplay{{\tenpoint$^{\hbox{\sevenrm\topsecno}}_{\hbox{\sevenrm\botsecno}}$}}
+
 \def\botsecno{\expandafter\takeone\botmark} % the first section on the
                                             % next page
-
-\newwrite\exampletable
-
-\newif\ifsaveparseoutput
-\newif\ifchecktable
+\newif\ifsepsectionchapter % do we put the section list in its own chapter?
 
 \def\finmod{%
-  \enddoublecols
-  \closeout\exampletable
   \parfillskip 0pt plus 1fil
   \def\grouptitle{NAMES OF THE SECTIONS}
   \let\topsecno=\nullsec
@@ -942,21 +982,18 @@
       \let\Xpdf\X
       %
       \ifpdftex 
-          \makebookmarks
-          \pdfdest name {NOS} fitb
-          \pdfoutline goto name {NOS} count -\secno {\outsecname}
-          \def\X##1:##2\X{\Xpdf##1:##2\X \firstsecno##1.%
-          {\toksF={}\makeoutlinetoks##2\outlinedone\outlinedone}%
-          \pdfoutline goto num \the\toksA \expandafter{\the\toksE}}
-      \else
-          \ifpdf
-              \special{pdf: outline -1 << /Title (\outsecname)
-                       /Dest [ @thispage /FitH @ypos ] >>}
-              \def\X##1:##2\X{\Xpdf##1:##2\X \firstsecno##1.%
-              {\toksF={}\makeoutlinetoks##2\outlinedone\outlinedone}%
-              \special{pdf: outline 0 << /Title (\the\toksE)
-                       /A << /S /GoTo /D (\romannumeral\the\toksA) >> >>}}
-          \fi
+          %\makebookmarks 
+          % move this to just before the contents so \inxmod has a 
+          % chance to close the \cont channel; AS
+          \ifsepsectionchapter\else\pdfdest name {NOS} fith \fi
+          %\pdfoutline goto name {NOS} count -\secno {\outsecname}%
+          %\def\X##1:##2\X{\Xpdf##1:##2\X \firstsecno##1.%
+              %{\toksF={}\makeoutlinetoks##2\outlinedone\outlinedone}%
+              %\pdfoutline goto num \the\toksA \expandafter{\the\toksE}%
+              % remove bookmarks for individual sections to avoid unpleasant
+              % pdf navigation artefacts; AS
+          %}
+          % pdf specials are not supported: AS
       \fi
   \fi
   %
@@ -967,10 +1004,48 @@
   \centerline{\sc A LIST OF ALL SECTIONS}
   \penalty300
   \medskip
-  \emergencystretch=10pt
+  \emergencystretch=12pt
+  \sectionlistsetup
   \readsections
 }
 
+\let\sectionlistsetup\relax
+
+\def\YYcontentsline#1#2#3#4#5{\ifnum#2=0 \smallbreak\fi
+    \line{\consetup{#2}#1
+      \rm\leaders\hbox to .5em{.\hfil}\hfil
+      \ \ifacro
+          \pdfstartlink attr {/Border [0 0 0]} goto page #4 {/FitH} \BlueGreen #3\Black\pdfendlink
+      \else#3\fi\hbox to3em{\hss#4}}}
+
+\def\YYwritebookmarkline#1#2#3#4#5{{%
+    \let\(=\let \let\)=\let \let\[=\let \let\]=\let \let\/=\let
+    \pdfoutline goto page #4 {#4} count 0 {#5}}}
+
+
+\def\makebookmarks{\let\ZZ=\writebookmarkline \let\YY\YYwritebookmarkline \readcontents\relax}
+
+\def\topofcontents{%
+    \null\vskip-3\baselineskip\centerline{C{\sc ONTENTS} (\sc\uppercase\expandafter{\title})}\medskip
+    \ifacro
+        \ifpdftex
+            \makebookmarks
+            \ifsepsectionchapter\else\pdfoutline goto name {NOS} count 0 {\outsecname}\fi% no section listing; AS
+            \pdfdest name {TOC} fith % bookmark for the table of contents
+        \fi
+    \fi
+    \let\YY\YYcontentsline
+}
+
+\def\botofcontents{\vfill
+  \ifpdftex\pdfoutline goto name {TOC} count 0 {Table of Contents}\fi 
+  \centerline{\covernote}} % this material will end the table of contents page
+
+\newwrite\exampletable
+
+\newif\ifsaveparseoutput
+\newif\ifchecktable
+
 % \Cee\ section macros
 
 % stage one macros for `\B' sections: collecting tokens
@@ -982,17 +1057,13 @@
 
 \let\oldB\B
 
-\long\def\Bvbpp#1\par{%
-    \Bvbp@#1\X\X$\E$\par
-}
-
 \long\def\Bvbpp#1\par{% the \vb{\yyendgame}\vb... is inserted by brack.pl
     \Bvbp@#1\cleanBtail\X\X$\E$\par
 }
 
 \def\cleanBtail\X\X$\E${}
 
-\long\def\Bvbp@#1\X#2\X$#3\E#4$#5\par{% new version of the above, experimental
+\long\def\Bvbp@#1\X#2\X$#3\E#4$#5\par{%
     \yystringempty{#5}%
         {%  this is a \Cee\ section (@c or @p); it is tempting to assume that the suffix
          %  is \X\X$\E$\par and forego the invocation of \Bvb@@, however, this is not always
@@ -1086,21 +1157,38 @@
 
 % URL typesetting
 
-\def\url#1{%
-    \hskip0pt plus .3\hsize\penalty100
+\def\urls#1#2{% make it possible to omit the `https://' nonsense
+    \hskip0pt plus .3\hsize\penalty1000
     \hskip0pt plus -.3\hsize
     {%
         \def~{\string~}%
         \ifmakepdf
-            \pdfURL{{\tt #1}}{#1}%
+            \pdfURL{{\tt #2}}{#1#2}%
         \else
-            {\tt #1}%
+            {\tt #2}%
         \fi
     }%
-    \hskip0pt plus .2\hsize\penalty100
-    \hskip0pt plus -.2\hsize
+    \hskip0pt plus .2\hsize\penalty1000
+    \hskip0pt plus -.2\hsize\relax % this is somewhat of an infidelity in \TeX's syntax
 }
 
+\def\urll#1#2{% make it possible to omit the `https://' nonsense
+    \hskip0pt plus .3\hsize\penalty1000
+    \hskip0pt plus -.3\hsize
+    {%
+        \def~{\string~}%
+        \ifmakepdf
+            \pdfURL{#2}{#1}%
+        \else
+            {\tt #2}%
+        \fi
+    }%
+    \hskip0pt plus .2\hsize\penalty1000
+    \hskip0pt plus -.2\hsize\relax % this is somewhat of an infidelity in \TeX's syntax
+}
+
+\def\url#1{\urls{}{#1}}
+
 % commonly used names
 
 \def\CWEB{\.{CWEB}}
@@ -1111,6 +1199,7 @@
 \def\noweb{\.{noweb}}
 \def\splint{\.{SPLinT}}
 \def\POSIX{{\sc POSIX}}
+\def\AST{{\sc AST}}
 \def\EAST{{\sc EAST}}
 \def\WEST{{\sc WEST}}
 \def\ISO{{\mc ISO}}
@@ -1146,13 +1235,130 @@
     }%
 }
 
+% a `union' to control command sequences in the .aux files; 
+\def\auxunionctl{}% here we add sequences that control namespace switching
+                  % although it is handled as a `union', we plan to execute this
+                  % sequence rather than use it as a storage list
+\newwrite\auxstream
+
+\def\initauxstream{% this command should be executed only after 
+                   % all the command sequances have been loaded (i.e. after
+                   % noweb.sty, dcols.sty, etc. have been loaded)
+    \immediate\openin\trystream=\jobname.aux
+    \ifeof\trystream
+    \else
+        \restorecslist{aux:global:activate}\auxunionctl
+        \auxunionctl % activate/deactivate individual subsets
+        \immediate\closein\trystream
+        \input \jobname.aux
+    \fi
+    \immediate\openout\auxstream=\jobname.aux
+    \restorecslist{aux:global:prestart}\auxunionctl
+    \auxunionctl
+}
+
+\def\everyendofjob{%
+    \restorecslist{aux:global:precutoff}\auxunionctl
+    \auxunionctl % write delayed data to the stream
+    \immediate\closeout\auxstream
+    \restorecslist{aux:global:preend}\auxunionctl
+    \auxunionctl % do end of run tasks for every command set that writes to aux stream
+    \message{Closed auxilary streams}%
+}
+
+% \end amendment, based on stackexchange question/answer by Bruno LeFloch
+% https://tex.stackexchange.com/questions/39279/test-whether-end-will-really-end-the-run/40894
+% with some simplifications (we do not really need to take care of every possible situation
+% since the \end command appears at a predictable spot)
+
+\def\newend{%
+    \ifdim\pagegoal=\maxdimen
+        \yybreak{\checkdeadcycles}%
+    \else
+        \yybreak{\end}% do nothing, the regular \output will take care of the endgame
+    \yycontinue
+}
+
+\def\checkdeadcycles{%
+    \ifnum\deadcycles=\z@
+        \yybreak{\testpageforstuff}%
+    \else
+        \yybreak{\end}% do nothing, the regular \output will take care of the endgame
+    \yycontinue
+}
+
+% insert the same material \end would insert (see The \TeX book, p.~264)
+\def\forceoutputagain{%
+  \prevdepth=-1000pt
+  \hbox{}\vfill\penalty-'10000000000
+}
+
+\def\testpageforstuff{% temporarily replace the output routine
+                      % to check if the page contains stuff other than boxes
+    \begingroup\output{\aftergroup\endgroup\testpageoutput}%
+    \forceoutputagain % call the new output routine
+}
+
+\def\testpageoutput{%
+    \deadcycles=\z@
+    \cleantemppage
+    \yyifpageempty % is there any stuff other than boxes in the vertical list?
+                   % this macro is only expanded if \pagegoal=\maxdimen and \deadcycles=0
+        {\everyendofjob}% vertical list is empty
+        {}% whatsit nodes present, let \end take care of them
+    \aftergroup\end
+    \unvbox255
+    \ifnum\outputpenalty=\@M % 10000 the break was not at a penalty item
+    \else
+         \penalty\outputpenalty
+    \fi
+}
+
+\def\cleantemppage{% remove material inserted by \forceoutputagain
+    \setbox255\vbox{%
+        \unvbox255
+        \unskip % remove \vfill
+        \setbox0\lastbox % remove \hbox{}
+        \unskip % remove \topskip
+    }%
+}
+
+\def\yyifpageempty{%
+    \setbox\z@\vbox{%
+        \vbox{}\unvcopy255\setbox0\lastbox
+        \expandafter
+    }%
+    \ifvoid\z@ %\vbox was not the last item, force output again
+        \yybreak{\yysecondoftwo}%
+    \else
+        \yybreak{\yyfirstoftwo}%
+    \yycontinue
+}
+
+\def\con{\par\vfill\eject % finish the section names
+% \ifodd\pageno\else\titletrue\null\vfill\eject\fi % for duplex printers
+  \rightskip 0pt \hyphenpenalty 50 \tolerance 200
+  \setpage \output={\normaloutput\page\lheader\rheader}
+  \titletrue % prepare to output the table of contents
+  \pageno=\contentspagenumber
+  \def\grouptitle{TABLE OF CONTENTS}
+  \message{Table of contents:}
+  \topofcontents \startpdf
+  \line{\hfil Section\hbox to3em{\hss Page}}
+  \let\ZZ=\contentsline
+  \readcontents\relax % read the contents info
+  \botofcontents 
+  \newend
+} % print the contents page(s) and terminate
+
 % sugar
 
 \def\FOREVER{{\bf forever}}
 
+% microtypography extensions: activate optical alignment
 \ifacro
     \ifpdftex
-        \input extras/texmf/macros/protcode.tex
+        \input other/texmf/macros/protcode.tex
         \pdfprotrudechars=2
         \setprotcode\tenrm
         \setprotcode\ninerm
@@ -1167,10 +1373,104 @@
         % do not stretch characters
         %\pdfdjustspacing=2 
         %\pdffontexpand\sevenrm 30 20 10 autoexpand
-        % TODO: use \pdfsavepos, \pdflastxpos, and \pdflastypos to
-        % save the position of index terms on the page
     \fi
 \fi
 
+% TODO: use \pdfsavepos, \pdflastxpos, and \pdflastypos to
+% save the position of index terms on the page
+
+% unstable macros
+
+% two column typesetting for short sections
+% CAUTION: while the macros below seem to work, their use requires a great deal of care
+% o they assume that the sections are narrow so only use them if you are reasonably sure that
+%   the width of the sections to be typeset as double column text are stable and not
+%   going to change much
+% o sections to be so typeset should not be part of `concatenated' @c sections; otherwise
+%   the noweb style section pointers in the margins will clash with the text in the adjacent
+%   column (this is not a concern if the traditional \CWEB\ referencing style is used
+
+\def\dcolbM{\expandafter\let\csname M\endcsname\thisM
+    \vskip 0pt plus 3\baselineskip\penalty-100 \vskip 0pt plus -3\baselineskip
+    \vskip\ht\strutbox
+    \vskip-\topskip % negate the \topskip at the beginning of the column box
+    \vskip-\smallskipamount
+    \vskip\intersecskip
+    \begindoublecols
+    \csname M\endcsname
+}
+
+\def\dcolbN{\expandafter\let\csname M\endcsname\thisN
+    \vskip\ht\strutbox
+    \vskip-\topskip % negate the \topskip at the beginning of the column box
+    \vskip-\smallskipamount
+    \vskip\intersecskip
+    \begindoublecols
+    \csname N\endcsname
+}
+
+\def\dcoleM{%
+    \vfil\enddoublecols
+    \crudelet{M}{thisM}%
+    \crudelet{N}{thisN}%
+    \csname M\endcsname
+}
+
+\def\dcoleN{%
+    \vfil\enddoublecols
+    \crudelet{M}{thisM}%
+    \crudelet{N}{thisN}%
+    \csname N\endcsname
+}
+
+\def\beginfoldedsections{% begin double column output starting with the next
+                         % \M or \N section
+    \ifbootstrapmode
+    \else
+        \crudelet{thisM}{M}%
+        \crudelet{thisN}{N}%
+        \crudelet{M}{dcolbM}%
+        \crudelet{N}{dcolbN}%
+    \fi
+}
+
+\def\endfoldedsections{% finish double column output starting with the next
+                       % \M or \N section
+    \ifbootstrapmode
+    \else
+        \crudelet{M}{dcoleM}%
+        \crudelet{N}{dcoleN}%
+    \fi
+}
+
+\def\crudelet#1#2{% ignore \outer (as a useful side effect these assignments can be skipped
+                  % as a part of an \if... statement without producing `incomplete \iftrue'
+                  % or like errors
+    \edef\next{\global\let\expandafter\nx\csname#1\endcsname\expandafter\nx\csname#2\endcsname}\next
+}
+
+\def\beginfoldedsectionshere{% similar to \beginfoldedsections but can be used immediately
+                             % before the @c portion of the section that will be typeset in two
+                             % columns; this way the \TeX\ portion of the section can still be
+                             % typeset in a single column
+    % save the current section macro to be restored by \endfoldedsections
+    \ifbootstrapmode
+    \else
+        \crudelet{thisN}{N}% both types of section macros are saved
+        \crudelet{thisM}{M}% just in case the section changes to an \M section
+        \vskip\ht\strutbox
+        \vskip-\topskip % negate the \topskip at the beginning of the column box
+        \vskip-\smallskipamount % undo the skip from \begindoublecols
+        \yskip
+        \begindoublecols
+        \parindent=1em
+    \fi
+}
+
+% support reproducible compilation
+\ifpdftex
+    \pdfinfoomitdate=1
+    \pdftrailerid{}%
+\fi
 \tenpoint