+% @acronym for "FBI", "NATO", and the like.
+% We print this one point size smaller, since it's intended for
+% all-uppercase.
+%
+\def\acronym#1{\doacronym #1,,\finish}
+\def\doacronym#1,#2,#3\finish{%
+ {\selectfonts\lsize #1}%
+ \def\temp{#2}%
+ \ifx\temp\empty \else
+ \space ({\unsepspaces \ignorespaces \temp \unskip})%
+ \fi
+ \null % reset \spacefactor=1000
+}
+
+% @abbr for "Comput. J." and the like.
+% No font change, but don't do end-of-sentence spacing.
+%
+\def\abbr#1{\doabbr #1,,\finish}
+\def\doabbr#1,#2,#3\finish{%
+ {\plainfrenchspacing #1}%
+ \def\temp{#2}%
+ \ifx\temp\empty \else
+ \space ({\unsepspaces \ignorespaces \temp \unskip})%
+ \fi
+ \null % reset \spacefactor=1000
+}
+
+% @asis just yields its argument. Used with @table, for example.
+%
+\def\asis#1{#1}
+
+% @math outputs its argument in math mode.
+%
+% One complication: _ usually means subscripts, but it could also mean
+% an actual _ character, as in @math{@var{some_variable} + 1}. So make
+% _ active, and distinguish by seeing if the current family is \slfam,
+% which is what @var uses.
+{
+ \catcode`\_ = \active
+ \gdef\mathunderscore{%
+ \catcode`\_=\active
+ \def_{\ifnum\fam=\slfam \_\else\sb\fi}%
+ }
+}
+% Another complication: we want \\ (and @\) to output a math (or tt) \.
+% FYI, plain.tex uses \\ as a temporary control sequence (for no
+% particular reason), but this is not advertised and we don't care.
+%
+% The \mathchar is class=0=ordinary, family=7=ttfam, position=5C=\.
+\def\mathbackslash{\ifnum\fam=\ttfam \mathchar"075C \else\backslash \fi}
+%
+\def\math{%
+ \tex
+ \mathunderscore
+ \let\\ = \mathbackslash
+ \mathactive
+ % make the texinfo accent commands work in math mode
+ \let\"=\ddot
+ \let\'=\acute
+ \let\==\bar
+ \let\^=\hat
+ \let\`=\grave
+ \let\u=\breve
+ \let\v=\check
+ \let\~=\tilde
+ \let\dotaccent=\dot
+ $\finishmath
+}
+\def\finishmath#1{#1$\endgroup} % Close the group opened by \tex.
+
+% Some active characters (such as <) are spaced differently in math.
+% We have to reset their definitions in case the @math was an argument
+% to a command which sets the catcodes (such as @item or @section).
+%
+{
+ \catcode`^ = \active
+ \catcode`< = \active
+ \catcode`> = \active
+ \catcode`+ = \active
+ \catcode`' = \active
+ \gdef\mathactive{%
+ \let^ = \ptexhat
+ \let< = \ptexless
+ \let> = \ptexgtr
+ \let+ = \ptexplus
+ \let' = \ptexquoteright
+ }
+}
+
+% @inlinefmt{FMTNAME,PROCESSED-TEXT} and @inlineraw{FMTNAME,RAW-TEXT}.
+% Ignore unless FMTNAME == tex; then it is like @iftex and @tex,
+% except specified as a normal braced arg, so no newlines to worry about.
+%
+\def\outfmtnametex{tex}
+%
+\long\def\inlinefmt#1{\doinlinefmt #1,\finish}
+\long\def\doinlinefmt#1,#2,\finish{%
+ \def\inlinefmtname{#1}%
+ \ifx\inlinefmtname\outfmtnametex \ignorespaces #2\fi
+}
+% For raw, must switch into @tex before parsing the argument, to avoid
+% setting catcodes prematurely. Doing it this way means that, for
+% example, @inlineraw{html, foo{bar} gets a parse error instead of being
+% ignored. But this isn't important because if people want a literal
+% *right* brace they would have to use a command anyway, so they may as
+% well use a command to get a left brace too. We could re-use the
+% delimiter character idea from \verb, but it seems like overkill.
+%
+\long\def\inlineraw{\tex \doinlineraw}
+\long\def\doinlineraw#1{\doinlinerawtwo #1,\finish}
+\def\doinlinerawtwo#1,#2,\finish{%
+ \def\inlinerawname{#1}%
+ \ifx\inlinerawname\outfmtnametex \ignorespaces #2\fi
+ \endgroup % close group opened by \tex.
+}
+
+
+\message{glyphs,}
+% and logos.
+
+% @@ prints an @, as does @atchar{}.
+\def\@{\char64 }
+\let\atchar=\@
+
+% @{ @} @lbracechar{} @rbracechar{} all generate brace characters.
+% Unless we're in typewriter, use \ecfont because the CM text fonts do
+% not have braces, and we don't want to switch into math.
+\def\mylbrace{{\ifmonospace\else\ecfont\fi \char123}}
+\def\myrbrace{{\ifmonospace\else\ecfont\fi \char125}}
+\let\{=\mylbrace \let\lbracechar=\{
+\let\}=\myrbrace \let\rbracechar=\}
+\begingroup
+ % Definitions to produce \{ and \} commands for indices,
+ % and @{ and @} for the aux/toc files.
+ \catcode`\{ = \other \catcode`\} = \other
+ \catcode`\[ = 1 \catcode`\] = 2
+ \catcode`\! = 0 \catcode`\\ = \other
+ !gdef!lbracecmd[\{]%
+ !gdef!rbracecmd[\}]%
+ !gdef!lbraceatcmd[@{]%
+ !gdef!rbraceatcmd[@}]%
+!endgroup
+
+% @comma{} to avoid , parsing problems.
+\let\comma = ,
+
+% Accents: @, @dotaccent @ringaccent @ubaraccent @udotaccent
+% Others are defined by plain TeX: @` @' @" @^ @~ @= @u @v @H.
+\let\, = \ptexc
+\let\dotaccent = \ptexdot
+\def\ringaccent#1{{\accent23 #1}}
+\let\tieaccent = \ptext
+\let\ubaraccent = \ptexb
+\let\udotaccent = \d
+
+% Other special characters: @questiondown @exclamdown @ordf @ordm
+% Plain TeX defines: @AA @AE @O @OE @L (plus lowercase versions) @ss.
+\def\questiondown{?`}
+\def\exclamdown{!`}
+\def\ordf{\leavevmode\raise1ex\hbox{\selectfonts\lllsize \underbar{a}}}
+\def\ordm{\leavevmode\raise1ex\hbox{\selectfonts\lllsize \underbar{o}}}
+
+% Dotless i and dotless j, used for accents.
+\def\imacro{i}
+\def\jmacro{j}
+\def\dotless#1{%
+ \def\temp{#1}%
+ \ifx\temp\imacro \ifmmode\imath \else\ptexi \fi
+ \else\ifx\temp\jmacro \ifmmode\jmath \else\j \fi
+ \else \errmessage{@dotless can be used only with i or j}%
+ \fi\fi
+}
+
+% The \TeX{} logo, as in plain, but resetting the spacing so that a
+% period following counts as ending a sentence. (Idea found in latex.)
+%
+\edef\TeX{\TeX \spacefactor=1000 }
+
+% @LaTeX{} logo. Not quite the same results as the definition in
+% latex.ltx, since we use a different font for the raised A; it's most
+% convenient for us to use an explicitly smaller font, rather than using
+% the \scriptstyle font (since we don't reset \scriptstyle and
+% \scriptscriptstyle).
+%
+\def\LaTeX{%
+ L\kern-.36em
+ {\setbox0=\hbox{T}%
+ \vbox to \ht0{\hbox{%
+ \ifx\textnominalsize\xwordpt
+ % for 10pt running text, \lllsize (8pt) is too small for the A in LaTeX.
+ % Revert to plain's \scriptsize, which is 7pt.
+ \count255=\the\fam $\fam\count255 \scriptstyle A$%
+ \else
+ % For 11pt, we can use our lllsize.
+ \selectfonts\lllsize A%
+ \fi
+ }%
+ \vss
+ }}%
+ \kern-.15em
+ \TeX
+}
+
+% Some math mode symbols.
+\def\bullet{$\ptexbullet$}
+\def\geq{\ifmmode \ge\else $\ge$\fi}
+\def\leq{\ifmmode \le\else $\le$\fi}
+\def\minus{\ifmmode -\else $-$\fi}