+ \if@nobreak\else\par\goodbreak\fi%
+ \global\@dheadfirsttrue%
+ \begingroup%
+ \let\@endparenv\relax%
+ \clubpenalty\@M \widowpenalty\@M \interlinepenalty50%
+ \@prog#1\endtabbing%
+ \endgroup%
+ \penalty\@M\@afterheading%
+ \list{}{\rightmargin\z@\topsep\z@}\item%
+}
+\def\desc@end{\endlist\after@desc\global\let\after@desc\saved@after@desc}
+
+%% \begin{describe}[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%% ...
+%% \end{describe}
+%%
+%% Describe some kind of program object. The CAT names the category of thing
+%% being described -- this will be shown in the header, and index. The
+%% SYNOPSIS is an implicit `prog' environment in which invoking the thing can
+%% be summarized.
+%%
+%% The {...}... are any additional arguments required by the category's kind
+%% (e.g., method specializers).
+%%
+%% The NAME is the name of the thing, which ends up in the index and
+%% cross-reference label. If omitted, it defaults to the first word of the
+%% SYNOPSIS, except that there are some special cases.
+%%
+%% The MOD is the modifier to apply. If omitted, it will usually default to
+%% `plain', but in the absence of a NAME, some kinds of synopses are
+%% recognized specially:
+%%
+%% * `setf (NAME ...) ...': selects NAME, and defaults MOD to `setf'.
+%%
+%% * `*NAME*': defaults MOD to `muffs'.
+%%
+%% * `:NAME': defaults MOD to `kwd'.
+\def\describe{\parse@dhd\desc@}
+\def\desc@#1#2#3#4#5{%
+ \global\@dheadindextrue%
+ \desc@begin{\dhead@{#1}{#2}{#3}{#4}{#5}}%
+}
+\let\enddescribe\desc@end
+
+%% \begin{describe*}
+%% {\dhead[MOD]{CAT}{...}...[NAME]{SYNOPSIS}
+%% ...}
+%% ...
+%% \end{describe*}
+%%
+%% This is the fancy form of `describe' for describing several different
+%% things at once.
+\@namedef{describe*}#1{\desc@begin{#1}}
+\expandafter\let\csname enddescribe*\endcsname\desc@end
+
+%% \parse@dlbl{NEXT}[MOD]{CAT}{...}...{LABEL}
+%%
+%% Parse a description label, and call
+%%
+%% NEXT{MOD}{CAT}{{...}...}{LABEL}
+%%
+%% This handles defaulting the MOD correctly, based on the LABEL text. See
+%% `\descref' for the details.
+\def\parse@dlbl#1{\@ifnextchar[{\parse@dlbl@a{#1}}{\parse@dlbl@c{#1}}}
+\def\parse@dlbl@a#1[#2]#3{\@desc@dispatch{descargs}{#3}{#1{#2}{#3}}}
+\def\parse@dlbl@c#1#2%
+ {\@desc@dispatch{descargs}{#2}{\parse@dlbl@cb{#1}{#2}}}
+\def\parse@dlbl@cb#1#2#3#4{%
+ \def\temp@##1##2*##3\q@{\def\temp@{##1##3}}\temp@#4*\q@%
+ \ifx\temp@\@starstar\def\next@{#1{muffs}{#2}{#3}{#4}}%
+ \else\def\temp@##1##2\q@{\def\temp@{##1}}\temp@#4\q@%
+ \if:\temp@\def\next@{#1{kwd}{#2}{#3}{#4}}
+ \else\def\next@{#1{plain}{#2}{#3}{#4}}\fi\fi%
+ \next@%
+}
+
+%% \descref[MOD]{CAT}{...}...{LABEL}[TEXT]
+%% \descref*[MOD]{CAT}{...}...{LABEL}
+%%
+%% Typesets a cross-reference to a described thing. The CAT names the
+%% category of thing being described, and the LABEL names the specific thing.
+%%
+%% The {...}... are any additional arguments required by the category's kind
+%% (e.g., method specializers).
+%%
+%% The MOD is the modifier to apply, similar (but subtly different from) to
+%% the `describe' environment. If omitted, it will usually default to
+%% `plain', but in the absence of a NAME, some kinds of synopses are
+%% recognized specially:
+%%
+%% * `*NAME*': defaults MOD to `muffs'.
+%%
+%% * `:NAME': defaults MOD to `kwd'.
+%%
+%% (`setf' is /not/ specially detected here. Write an explicit `setf'
+%% modifier if necessary, because it's no more typing.)
+%%
+%% Usually a page-number cross-reference is included, so as to help readers
+%% of a dead-tree copy; this is suppressed by the `*' version.
+\def\descref{\@ifstar%
+ {\parse@dlbl{\descref@i\relax\@gobble\relax}}%
+ {\parse@dlbl{\descref@i{ (}\autopageref)}}}
+\def\descref@i#1#2#3#4#5#6#7{\@ifnextchar@preserve[%
+ % {PGA}{PGB}{PGC}{MOD}{CAT}{{...}...}{LABEL}
+ {\descref@ii{#1}{#2}{#3}{#4}{#5}{#6}{#7}}%
+ {\descref@iii{#1}{#2}{#3}{#4}{#5}{#6}{#7}{}}}
+\def\descref@ii#1#2#3#4#5#6#7[#8]%
+ % {PGA}{PGB}{PGC}{MOD}{CAT}{{...}...}{LABEL}[AFTER]
+ {\descref@iii{#1}{#2}{#3}{#4}{#5}{#6}{#7}{ #8}}
+\def\descref@iii#1#2#3#4#5#6#7#8{%
+ % {PGA}{PGB}{PGC}{MOD}{CAT}{{...}...}{LABEL}{AFTER}
+ \begingroup%
+ \let\protect\@empty\def\@uscore{-\@gobble}%
+ \edef\temp@{\@desc@dispatch{desclabel}{#5}{#4}{#5}#6{#7}}%
+ \hyperref[\temp@]{\code{#7}}#8%
+ #1#2{\temp@}#3%
+ \endgroup%