[CTWILL] Add editorial material for 'ctwill.pdf'.

It's a long and winded road to run CTWILL on its own source code in
order to produce a nice and user-friendly rendering in PDF.  :o)

git-svn-id: svn://tug.org/texlive/trunk@55647 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 772 insertions, 0 deletions

diff --git a/Build/source/texk/web2c/cwebdir/ctwill-mini.ch b/Build/source/texk/web2c/cwebdir/ctwill-mini.ch
new file mode 100644
index 00000000000..2c5b3d4963a
--- /dev/null
+++ b/Build/source/texk/web2c/cwebdir/ctwill-mini.ch
@@ -0,0 +1,772 @@
+@x
+@** Introduction.
+@y
+\ifacro \ifx\undefined\pdfpagewidth\else
+  \pdfpagewidth=\pagewd  \advance\pdfpagewidth by 2cm
+  \pdfpageheight=\pageht \advance\pdfpageheight by 5cm
+  \ifpdftex \pdfhorigin=1cm \pdfvorigin=1cm
+  \else \global\hoffset=-1.54cm \global\voffset=-1.54cm \fi
+\fi\fi
+
+@** Introduction.
+@z
+
+@x
+@ Here is a sort of user manual for \.{CTWILL}---which is exactly like
+@y
+@* \.{CTWILL} user manual.
+Here is a sort of user manual for \.{CTWILL}---which is exactly like
+@z
+
+@x
+give it the necessary hints in other places via your change file.
+@y
+give it the necessary hints in other places via your change file.
+@-f@>
+@-x@>
+@z
+
+@x
+The current meaning of every identifier is initially `\.{\\uninitialized}'.
+@y
+@ The current meaning of every identifier is initially `\.{\\uninitialized}'.
+@z
+
+@x
+must have fewer than 50 characters. If the \TeX\ part starts
+@y
+must have fewer than 50 characters.
+
+@d max_tex_chars 50 /* limit on the \TeX\ part of a meaning */
+
+@ If the \TeX\ part starts
+@z
+
+@x
+@d max_tex_chars 50 /* limit on the \TeX\ part of a meaning */
+@y
+@z
+
+@x
+you have to change them also in the file |"common.w"|.
+@y
+you have to change them also in file |"common.w"|.
+@z
+
+@x
+@ The next few sections contain stuff from the file |"common.w"| that must
+@y
+@r @ The next few sections contain stuff from the file |"common.w"| that must
+@z
+
+@x
+internationalization.
+@y
+internationalization.
+@-A@>
+@-HAVE_GETTEXT@>
+@-STRING@>
+@z
+
+@x
+@ Code related to input routines:
+@y
+@ Code related to input routines:
+@-c@>
+@z
+
+@x
+@ Code related to identifier and section name storage:
+@y
+@ Code related to identifier and section name storage:
+@-c@>
+@z
+
+@x
+@ Code related to error handling:
+@y
+@ Code related to error handling:
+@-s@>
+@z
+
+@x
+@ Code related to section numbers:
+@y
+@r @ Code related to section numbers:
+@z
+
+@x
+@ Code relating to output:
+@y
+@ Code relating to output:
+@-a@>
+@-b@>
+@-c@>
+@z
+
+@x
+@* Data structures exclusive to {\tt CWEAVE}.
+@y
+@* Data structures exclusive to {\tt CWEAVE}.
+@-a@>
+@z
+
+@x
+@ The other large memory area in \.{CWEAVE} keeps the cross-reference data.
+@y
+@ The other large memory area in \.{CWEAVE} keeps the cross-reference data.
+@-p@>
+@-x@>
+@z
+
+@x
+@ \.{CTWILL} also has special data structures to keep track of current
+@y
+@r @ \.{CTWILL} also has special data structures to keep track of current
+@z
+
+@x
+@ The |new_meaning| routine changes the current ``permanent meaning''
+@y
+@r @ The |new_meaning| routine changes the current ``permanent meaning''
+@z
+
+@x
+@ A new cross-reference for an identifier is formed by calling |new_xref|,
+@y
+@ A new cross-reference for an identifier is formed by calling |new_xref|,
+@-a@>
+@-c@>
+@z
+
+@x
+id_lookup("do",NULL,do_like);
+@y
+@ @<Store all...@>=
+id_lookup("do",NULL,do_like);
+@z
+
+@x
+id_lookup("undef",NULL,if_like);
+@y
+@ @<Store all...@>=
+id_lookup("undef",NULL,if_like);
+@z
+
+@x
+@ Control codes are converted to \.{CWEAVE}'s internal
+@y
+@r @ Control codes are converted to \.{CWEAVE}'s internal
+@z
+
+@x
+\yskip\hang |xref_roman|, |xref_wildcard|, |xref_typewriter|, |TeX_string|,
+|meaning|, |suppress|,
+|verbatim|: The values of |id_first| and |id_loc| will have been set to
+the beginning and ending-plus-one locations in the buffer.
+
+\yskip\hang |section_name|: In this case the global variable |cur_section| will
+point to the |byte_start| entry for the section name that has just been scanned.
+The value of |cur_section_char| will be |'('| if the section name was
+preceded by \.{@@(} instead of \.{@@<}.
+@y
+{\raggedright
+\yskip\hang |xref_roman|, |xref_wildcard|, |xref_typewriter|, |TeX_string|,
+|meaning|, |suppress|,
+and |verbatim|: The values of |id_first| and |id_loc| will have been set to
+the beginning and ending-plus-one locations in the buffer.
+
+\yskip\hang |section_name|: In this case the global variable |cur_section| will
+point to the\hfil\break |byte_start| entry for the section name that has just been scanned.
+The value of |cur_section_char| will be |'('| if the section name was
+preceded by \.{@@(} instead of \.{@@<}.\par}
+@z
+
+@x
+@ As one might expect, |get_next| consists mostly of a big switch
+@y
+@ As one might expect, |get_next| consists mostly of a big switch
+@-c@>
+@z
+
+@x
+@ The following code assigns values to the combinations \.{++},
+@y
+@ The following code assigns values to the combinations \.{++},
+@-c@>
+@z
+
+@x
+@ @<Put section name...@>=
+@y
+@r @ @<Put section name...@>=
+@z
+
+@x
+with |next_control!='|'| and ends with |next_control>=format_code|. Thus, it
+@y
+with |next_control| |{}!='|'| and ends with |next_control>=format_code|.
+Thus, it
+@z
+
+@x
+@ Finally, when the \TEX/ and definition parts have been treated, we have
+|next_control>=begin_C|.
+@y
+@ Finally, when the \TEX/ and definition parts have been treated, we have
+\hfil\break|next_control>=begin_C|.
+@z
+
+@x
+@ The |flush_buffer| routine empties the buffer up to a given breakpoint,
+@y
+@ The |flush_buffer| routine empties the buffer up to a given breakpoint,
+@-c@>
+@z
+
+@x
+@ When we are copying \TEX/ source material, we retain line breaks
+@y
+@r @ When we are copying \TEX/ source material, we retain line breaks
+@z
+
+@x
+@ When we wish to append one character |c| to the output buffer, we write
+@y
+@ When we wish to append one character |c| to the output buffer, we write
+@-c@>
+@z
+
+@x
+@ We get to this section only in the unusual case that the entire output line
+@y
+@r @ We get to this section only in the unusual case that the entire output line
+@z
+
+@x
+@ The |copy_comment| function issues a warning if more braces are opened than
+@y
+@ The |copy_comment| function issues a warning if more braces are opened than
+@-t@>
+@z
+
+@x
+@ @<Copy special things when |c=='@@'...@>=
+@y
+@r @ @<Copy special things when |c=='@@'...@>=
+@z
+
+@x
+@ Here is a list of the category codes that scraps can have.
+@y
+@r @ Here is a list of the category codes that scraps can have.
+@z
+
+@x
+@ The token lists for translated \TEX/ output contain some special control
+@y
+@r @ The token lists for translated \TEX/ output contain some special control
+@-n@>
+@z
+
+@x
+\yskip\noindent All of these tokens are removed from the \TEX/ output that
+@y
+@ All of these tokens are removed from the \TEX/ output that
+@z
+
+@x
+|n| is the section number.
+@y
+|n| is the section number.
+@-n@>
+@z
+
+@x
+@ The raw input is converted into scraps according to the following table,
+@y
+@* From raw input to scraps.
+@-c@>
+\advance \hsize by 4cm
+\ifx\undefined\pdfpagewidth \else \advance \pdfpagewidth by 4cm \fi
+The raw input is converted into scraps according to the following table,
+@z
+
+@x
+\yskip\halign{\quad#\hfil&\quad#\hfil&\quad\hfil#\hfil\cr
+@y
+\yskip\halign{\quad#\hfil&\quad\hbox to11cm{#\hfil}&\quad\hfil#\hfil\cr
+@z
+
+@x
+\.>&|prerangle|: \.{\\rangle}&yes\cr
+@y
+\.>&|prerangle|: \.{\\rangle}&yes\cr}
+
+@ Cont.
+
+\yskip\halign{\quad#\hfil&\quad#\hfil&\quad\hfil#\hfil\cr
+%\vskip\halign{\quad#\hfil&\quad\hbox to11cm{#\hfil}&\quad\hfil#\hfil\cr
+@z
+
+@x
+\.{continue}&|case_like|: \stars&maybe\cr
+@y
+\.{continue}&|case_like|: \stars&maybe\cr}
+
+@r @ Cont.
+
+\yskip\halign{\quad#\hfil&\quad#\hfil&\quad\hfil#\hfil\cr
+%\vskip\halign{\quad#\hfil&\quad\hbox to11cm{#\hfil}&\quad\hfil#\hfil\cr
+@z
+
+@x
+\.{long}&|raw_int|: \stars&maybe\cr
+@y
+\.{long}&|raw_int|: \stars&maybe\cr}
+
+@ Cont.
+
+\yskip\halign{\quad#\hfil&\quad#\hfil&\quad\hfil#\hfil\cr
+%\vskip\halign{\quad#\hfil&\quad\hbox to11cm{#\hfil}&\quad\hfil#\hfil\cr
+@z
+
+@x
+\.{try}&|else_like|: \stars&maybe\cr
+@y
+\.{try}&|else_like|: \stars&maybe\cr}
+
+@r @ Cont.
+
+\yskip\halign{\quad#\hfil&\quad#\hfil&\quad\hfil#\hfil\cr
+%\vskip\halign{\quad#\hfil&\quad\hbox to11cm{#\hfil}&\quad\hfil#\hfil\cr
+@z
+
+@x
+@i prod-twill.w
+@y
+@i prod-twill.w
+@-any@>
+@-any_other@>
+@-g@>
+@-in@>
+@-z@>
+@z
+
+@x
+@* Implementing the productions.
+@y
+@* Implementing the productions.  \advance \hsize by -4cm
+\ifx\undefined\pdfpagewidth \else \advance \pdfpagewidth by -4cm \fi
+@z
+
+@x
+the category codes |pp->cat,@,@,(pp+1)->cat|$,\,\,\ldots\,$
+@y
+the category codes |pp->cat|, |(pp+1)->cat|, $\,\ldots\,$
+@z
+
+@x
+@ @<Set init...@>=
+@y
+@r @ @<Set init...@>=
+@z
+
+@x
+@ Token lists in |@!tok_mem| are composed of the following kinds of
+@y
+@ Token lists in |@!tok_mem| are composed of the following kinds of
+@-p@>
+@z
+
+@x
+#ifdef DEAD_CODE /* not used in |main| */
+@y
+@ Debugging routine, use at your own risk.
+@-DEAD_CODE@>
+
+@c
+#ifdef DEAD_CODE /* not used in |main| */
+@z
+
+@x
+@ @<Print token |r|...@>=
+@y
+@r @ @<Print token |r|...@>=
+@z
+
+@x
+@ The production rules listed above are embedded directly into \.{CWEAVE},
+@y
+@ The production rules listed above are embedded directly into \.{CWEAVE},
+@-a@>
+@-c@>
+@-d@>
+@-j@>
+@-k@>
+@-n@>
+@-pp@>
+@z
+
+@x
+The code below is an exact translation of the production rules into
+@y
+@r @ The code below is an exact translation of the production rules into
+@-a@>
+@z
+
+@x
+@ Let us consider the big switch for productions now, before looking
+@y
+@r @ Let us consider the big switch for productions now, before looking
+@z
+
+@x
+  switch (pp->cat) {
+    case exp: @<Cases for |exp|@>; @+break;
+    case lpar: @<Cases for |lpar|@>; @+break;
+    case unop: @<Cases for |unop|@>; @+break;
+    case ubinop: @<Cases for |ubinop|@>; @+break;
+    case binop: @<Cases for |binop|@>; @+break;
+    case cast: @<Cases for |cast|@>; @+break;
+    case sizeof_like: @<Cases for |sizeof_like|@>; @+break;
+    case int_like: @<Cases for |int_like|@>; @+break;
+    case public_like: @<Cases for |public_like|@>; @+break;
+    case colcol: @<Cases for |colcol|@>; @+break;
+    case decl_head: @<Cases for |decl_head|@>; @+break;
+    case decl: @<Cases for |decl|@>; @+break;
+    case base: @<Cases for |base|@>; @+break;
+    case struct_like: @<Cases for |struct_like|@>; @+break;
+    case struct_head: @<Cases for |struct_head|@>; @+break;
+    case fn_decl: @<Cases for |fn_decl|@>; @+break;
+    case function: @<Cases for |function|@>; @+break;
+    case lbrace: @<Cases for |lbrace|@>; @+break;
+    case if_like: @<Cases for |if_like|@>; @+break;
+    case else_like: @<Cases for |else_like|@>; @+break;
+    case else_head: @<Cases for |else_head|@>; @+break;
+    case if_clause: @<Cases for |if_clause|@>; @+break;
+    case if_head: @<Cases for |if_head|@>; @+break;
+    case do_like: @<Cases for |do_like|@>; @+break;
+    case case_like: @<Cases for |case_like|@>; @+break;
+    case catch_like: @<Cases for |catch_like|@>; @+break;
+    case tag: @<Cases for |tag|@>; @+break;
+    case stmt: @<Cases for |stmt|@>; @+break;
+    case semi: @<Cases for |semi|@>; @+break;
+    case lproc: @<Cases for |lproc|@>; @+break;
+    case section_scrap: @<Cases for |section_scrap|@>; @+break;
+    case insert: @<Cases for |insert|@>; @+break;
+    case prelangle: @<Cases for |prelangle|@>; @+break;
+    case prerangle: @<Cases for |prerangle|@>; @+break;
+    case langle: @<Cases for |langle|@>; @+break;
+    case template_like: @<Cases for |template_like|@>; @+break;
+    case new_like: @<Cases for |new_like|@>; @+break;
+    case new_exp: @<Cases for |new_exp|@>; @+break;
+    case ftemplate: @<Cases for |ftemplate|@>; @+break;
+    case for_like: @<Cases for |for_like|@>; @+break;
+    case raw_ubin: @<Cases for |raw_ubin|@>; @+break;
+    case const_like: @<Cases for |const_like|@>; @+break;
+    case raw_int: @<Cases for |raw_int|@>; @+break;
+    case operator_like: @<Cases for |operator_like|@>; @+break;
+    case typedef_like: @<Cases for |typedef_like|@>; @+break;
+    case delete_like: @<Cases for |delete_like|@>; @+break;
+    case question: @<Cases for |question|@>; @+break;
+  }
+  pp++; /* if no match was found, we move to the right */
+}
+@y
+  switch (pp->cat) {
+    @<Cases for |pp->cat|@>@;
+  }
+  pp++; /* if no match was found, we move to the right */
+}
+
+@ @<Cases for |pp->cat|@>=
+    case exp: @<Cases for |exp|@>; @+break;
+    case lpar: @<Cases for |lpar|@>; @+break;
+    case unop: @<Cases for |unop|@>; @+break;
+    case ubinop: @<Cases for |ubinop|@>; @+break;
+    case binop: @<Cases for |binop|@>; @+break;
+    case cast: @<Cases for |cast|@>; @+break;
+    case sizeof_like: @<Cases for |sizeof_like|@>; @+break;
+    case int_like: @<Cases for |int_like|@>; @+break;
+    case public_like: @<Cases for |public_like|@>; @+break;
+    case colcol: @<Cases for |colcol|@>; @+break;
+    case decl_head: @<Cases for |decl_head|@>; @+break;
+    case decl: @<Cases for |decl|@>; @+break;
+    case base: @<Cases for |base|@>; @+break;
+    case struct_like: @<Cases for |struct_like|@>; @+break;
+    case struct_head: @<Cases for |struct_head|@>; @+break;
+    case fn_decl: @<Cases for |fn_decl|@>; @+break;
+    case function: @<Cases for |function|@>; @+break;
+    case lbrace: @<Cases for |lbrace|@>; @+break;
+    case if_like: @<Cases for |if_like|@>; @+break;
+    case else_like: @<Cases for |else_like|@>; @+break;
+    case else_head: @<Cases for |else_head|@>; @+break;
+    case if_clause: @<Cases for |if_clause|@>; @+break;
+    case if_head: @<Cases for |if_head|@>; @+break;
+    case do_like: @<Cases for |do_like|@>; @+break;
+    case case_like: @<Cases for |case_like|@>; @+break;
+    case catch_like: @<Cases for |catch_like|@>; @+break;
+    case tag: @<Cases for |tag|@>; @+break;
+    case stmt: @<Cases for |stmt|@>; @+break;
+    case semi: @<Cases for |semi|@>; @+break;
+    case lproc: @<Cases for |lproc|@>; @+break;
+    case section_scrap: @<Cases for |section_scrap|@>; @+break;
+    case insert: @<Cases for |insert|@>; @+break;
+    case prelangle: @<Cases for |prelangle|@>; @+break;
+    case prerangle: @<Cases for |prerangle|@>; @+break;
+    case langle: @<Cases for |langle|@>; @+break;
+    case template_like: @<Cases for |template_like|@>; @+break;
+    case new_like: @<Cases for |new_like|@>; @+break;
+    case new_exp: @<Cases for |new_exp|@>; @+break;
+    case ftemplate: @<Cases for |ftemplate|@>; @+break;
+    case for_like: @<Cases for |for_like|@>; @+break;
+    case raw_ubin: @<Cases for |raw_ubin|@>; @+break;
+    case const_like: @<Cases for |const_like|@>; @+break;
+    case raw_int: @<Cases for |raw_int|@>; @+break;
+    case operator_like: @<Cases for |operator_like|@>; @+break;
+    case typedef_like: @<Cases for |typedef_like|@>; @+break;
+    case delete_like: @<Cases for |delete_like|@>; @+break;
+    case question: @<Cases for |question|@>; @+break;
+@z
+
+@x
+of identifiers in case labels.
+
+If the first identifier is the keyword `\&{operator}', we give up;
+@y
+of identifiers in case labels.
+If the first identifier is the keyword `\&{operator}', we give up;
+@z
+
+@x
+@ The scraps currently being parsed must be inspected for any
+@y
+@r @ The scraps currently being parsed must be inspected for any
+@z
+
+@x
+|make_reserved|, hence |tok_loc| has been set.
+@y
+\hfil\break|make_reserved|, hence |tok_loc| has been set.
+@z
+
+@x
+@ The trickiest part of \.{CTWILL} is the procedure |make_ministring(l)|,
+@y
+@ The trickiest part of \.{CTWILL} is the procedure |make_ministring(l)|,
+@-b@>
+@z
+
+@x
+@ @<Cases for |lpar|@>=
+@y
+@r @ @<Cases for |lpar|@>=
+@z
+
+@x
+@ Outdent after parameter declarations with option \.{-i}.
+@y
+@r @ Outdent after parameter declarations with option \.{-i}.
+@z
+
+@x
+@ Here's the |squash| procedure, which
+@y
+@r @ Here's the |squash| procedure, which
+@z
+
+@x
+@ The following macro is used to append a scrap whose tokens have just
+@y
+@ The following macro is used to append a scrap whose tokens have just
+@-b@>
+@-c@>
+@z
+
+@x
+@ @d cur_end cur_state.end_field /* current ending location in |tok_mem| */
+@y
+@r @ @d cur_end cur_state.end_field /* current ending location in |tok_mem| */
+@z
+
+@x
+called when |stack_ptr==1|.
+@y
+called when |stack_ptr| |==1|.
+@z
+
+@x
+  text_pointer save_text_ptr;
+  sixteen_bits save_next_control; /* values to be restored */
+  text_pointer p; /* translation of the \CEE/ text */
+@y
+  text_pointer save_text_ptr, p; /* translation of the \CEE/ text */
+  sixteen_bits save_next_control; /* values to be restored */
+@z
+
+@x
+@ An identifier of length one does not have to be enclosed in braces, and it
+@y
+@r @ An identifier of length one does not have to be enclosed in braces, and it
+@z
+
+@x
+else @<Look ahead for strongest line break, |goto reswitch|@>
+@y
+else {@<Look ahead for strongest line break, |goto reswitch|@>}
+@z
+
+@x
+@<Look ahead for st...@>= {
+@y
+@<Look ahead for st...@>=
+@z
+
+@x
+}
+@y
+@z
+
+@x
+@ @<Output saved...@>=
+@y
+@r @ @<Output saved...@>=
+@z
+
+@x
+@ The output file will contain the control sequence \.{\\Y} between non-null
+@y
+@r @ The output file will contain the control sequence \.{\\Y} between non-null
+@z
+
+@x
+@<Translate the \T...@>= do {
+@y
+@<Translate the \T...@>= do {@+
+@z
+
+@x
+|next_control>=begin_C|. We will make the global variable |this_section|
+@y
+\hfil\break|next_control>=begin_C|. We will make the global variable |this_section|
+@z
+
+@x
+@ @<Translate the \CEE/...@>=
+@y
+@r @ @<Translate the \CEE/...@>=
+@z
+
+@x
+@ The |footnote| procedure gives cross-reference information about
+@y
+@r @ The |footnote| procedure gives cross-reference information about
+@z
+
+@x
+@ @<Flag the usage of this identifier, for the mini-index@>=
+@y
+@<Flag the usage of this identifier, for the mini-index@>=
+@z
+
+@x
+@ @<Output information about usage of id's defined in other sections@>=
+@y
+@r @ @<Output information about usage of id's defined in other sections@>=
+@z
+
+@x
+the index section itself---NOT!
+
+@<Global...@>=
+sixteen_bits k_section; /* runs through the sections */
+@y
+the index section itself---NOT!
+@z
+
+@x
+@ A left-to-right radix sorting method is used, since this makes it easy to
+@y
+@ A left-to-right radix sorting method is used, since this makes it easy to
+@-c@>
+@z
+
+@x
+name_pointer blink[max_names]; /* links in the buckets */
+@y
+name_pointer blink[max_names]; /* links in the buckets */
+sixteen_bits k_section; /* runs through the sections */
+@z
+
+@x
+@ During the sorting phase we shall use the |cat| and |trans| arrays from
+@y
+@ During the sorting phase we shall use the |cat| and |trans| arrays from
+@-j@>
+@-k@>
+@z
+
+@x
+$|collate|[0]<|collate|[1]<\cdots<|collate|[100]$.
+@y
+|collate[0]| $<$|collate[1]|$<\cdots<$|collate[100]|.
+@z
+
+@x
+    else {char *j;
+@y
+    else {@+char *j;
+@z
+
+@x
+@ Because on some systems the difference between two pointers is a |long|
+@y
+@r @ Because on some systems the difference between two pointers is a |long|
+@z
+
+@x
+care for keeping the original section numbering intact.}
+@y
+care for keeping the original section numbering intact.
+\smallskip
+\noindent Moreover, this heavily redacted version of \.{\itt ctwill.pdf} had to
+meddle with the section numbering even more, spreading tabular material over
+several sections and splitting long sections into smaller chunks in order to
+fix overful pages---both horizontally and vertically---, to make the overall
+appearance of the \.{\itt CTWILL} documentation most pleasing to the
+reader's~eye.
+
+Please do not try to compare this \.{\itt ctwill.pdf} to the one created by
+\.{\itt CWEAVE} instead of \.{\itt CTWILL}; the section numbering will be
+even more ``off'' from \.{\itt cweave.w}.  Care has been taken to give a
+faithful overall rendering of \.{\itt CTWILL}'s code, though.
+\bigskip
+\noindent Enjoy!}
+@z
+
+@x
+@* Function declarations.  Here are declarations---conforming to
+@y
+@* Function declarations.  Here are declarations---conforming to
+@-DEAD_CODE@>
+@z
+
+@x
+extern const char *use_language; /* prefix to \.{cwebmac.tex} in \TEX/ output */
+@y
+extern const char *use_language; /* prefix to \.{ctwimac.tex} in \TEX/ output */
+@z
+
+@x
+@** Index.
+If you have read and understood the code for Phase III above, you know what
+is in this index and how it got here. All sections in which an identifier is
+used are listed with that identifier, except that reserved words are
+indexed only when they appear in format definitions, and the appearances
+of identifiers in section names are not indexed. Underlined entries
+correspond to where the identifier was declared. Error messages, control
+sequences put into the output, and a few
+other things like ``recursion'' are indexed here too.
+@y
+@z