+\def\worddistinct{distinct}
+\def\wordexample{example}
+\def\wordcode{code}
+
+% Default is `distinct'.
+\kbdinputstyle distinct
+
+% @kbd is like @code, except that if the argument is just one @key command,
+% then @kbd has no effect.
+\def\kbd#1{{\def\look{#1}\expandafter\kbdsub\look??\par}}
+
+\def\xkey{\key}
+\def\kbdsub#1#2#3\par{%
+ \def\one{#1}\def\three{#3}\def\threex{??}%
+ \ifx\one\xkey\ifx\threex\three \key{#2}%
+ \else{\tclose{\kbdfont\setupmarkupstyle{kbd}\look}}\fi
+ \else{\tclose{\kbdfont\setupmarkupstyle{kbd}\look}}\fi
+}
+
+% definition of @key that produces a lozenge. Doesn't adjust to text size.
+%\setfont\keyrm\rmshape{8}{1000}{OT1}
+%\font\keysy=cmsy9
+%\def\key#1{{\keyrm\textfont2=\keysy \leavevmode\hbox{%
+% \raise0.4pt\hbox{\angleleft}\kern-.08em\vtop{%
+% \vbox{\hrule\kern-0.4pt
+% \hbox{\raise0.4pt\hbox{\vphantom{\angleleft}}#1}}%
+% \kern-0.4pt\hrule}%
+% \kern-.06em\raise0.4pt\hbox{\angleright}}}}
+
+% definition of @key with no lozenge. If the current font is already
+% monospace, don't change it; that way, we respect @kbdinputstyle. But
+% if it isn't monospace, then use \tt.
+%
+\def\key#1{{\setupmarkupstyle{key}%
+ \nohyphenation
+ \ifmonospace\else\tt\fi
+ #1}\null}
+
+% @clicksequence{File @click{} Open ...}
+\def\clicksequence#1{\begingroup #1\endgroup}
+
+% @clickstyle @arrow (by default)
+\parseargdef\clickstyle{\def\click{#1}}
+\def\click{\arrow}
+
+% Typeset a dimension, e.g., `in' or `pt'. The only reason for the
+% argument is to make the input look right: @dmn{pt} instead of @dmn{}pt.
+%
+\def\dmn#1{\thinspace #1}
+
+% @l was never documented to mean ``switch to the Lisp font'',
+% and it is not used as such in any manual I can find. We need it for
+% Polish suppressed-l. --karl, 22sep96.
+%\def\l#1{{\li #1}\null}
+
+% @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
+ % have to provide another name for sup operator
+ \let\mathopsup=\sup
+ $\finishmath
+}
+\def\finishmath#1{#1$\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
+ }
+}
+
+% for @sub and @sup, if in math mode, just do a normal sub/superscript.
+% If in text, use math to place as sub/superscript, but switch
+% into text mode, with smaller fonts. This is a different font than the
+% one used for real math sub/superscripts (8pt vs. 7pt), but let's not
+% fix it (significant additions to font machinery) until someone notices.
+%
+\def\sub{\ifmmode \expandafter\sb \else \expandafter\finishsub\fi}
+\def\finishsub#1{$\sb{\hbox{\selectfonts\lllsize #1}}$}%
+%
+\def\sup{\ifmmode \expandafter\ptexsp \else \expandafter\finishsup\fi}
+\def\finishsup#1{$\ptexsp{\hbox{\selectfonts\lllsize #1}}$}%
+
+% @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
+}
+%
+% @inlinefmtifelse{FMTNAME,THEN-TEXT,ELSE-TEXT} expands THEN-TEXT if
+% FMTNAME is tex, else ELSE-TEXT.
+\long\def\inlinefmtifelse#1{\doinlinefmtifelse #1,,,\finish}
+\long\def\doinlinefmtifelse#1,#2,#3,#4,\finish{%
+ \def\inlinefmtname{#1}%
+ \ifx\inlinefmtname\outfmtnametex \ignorespaces #2\else \ignorespaces #3\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.
+}