[groff] 19/31: eqn(1): List recognized primitives, predef macros.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 8f841ba67cc98dc5bb8ade57c440261819e71067
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Sun Aug 14 19:34:24 2022 -0500

    eqn(1): List recognized primitives, predef macros.
    
    * src/preproc/eqn/eqn.1.man: Expand to include lists of recognized
      primitives and predefined macros.
    
    Also eliminate "Controlling delimiters" subsection, relocating the
    extended behavior of the "delim" primitive to the "Extended primitives"
    subsection.
    
    Also discuss the necessity of quoting at greater length.  See
    <https://lists.gnu.org/archive/html/bug-groff/2022-06/msg00265.html>.
---
 ChangeLog                 |   5 +
 src/preproc/eqn/eqn.1.man | 228 +++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 202 insertions(+), 31 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 61bee309c..ee3612acc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2022-08-14  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * src/preproc/eqn/eqn.1.man: Expand to include lists of
+       recognized primitives and predefined macros.
+
 2022-08-04  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * NEWS: Add item for new groff mm `V` register support.
diff --git a/src/preproc/eqn/eqn.1.man b/src/preproc/eqn/eqn.1.man
index 90b38215c..dc75f1632 100644
--- a/src/preproc/eqn/eqn.1.man
+++ b/src/preproc/eqn/eqn.1.man
@@ -8,7 +8,7 @@
 .\" Legal Terms
 .\" ====================================================================
 .\"
-.\" Copyright (C) 1989-2020 Free Software Foundation, Inc.
+.\" Copyright (C) 1989-2022 Free Software Foundation, Inc.
 .\"
 .\" Permission is granted to make and distribute verbatim copies of this
 .\" manual provided the copyright notice and this permission notice are
@@ -213,21 +213,6 @@ or
 .
 .
 .\" ====================================================================
-.SS "Controlling delimiters"
-.\" ====================================================================
-.
-.I eqn
-recognizes
-.RB \[lq] "delim on" \[rq]
-as a command to restore the delimiters which have been previously
-disabled with a call to
-.RB \[lq] "delim off" \[rq].
-.
-If delimiters haven't been specified,
-these commands have no effect.
-.
-.
-.\" ====================================================================
 .SS "Automatic spacing"
 .\" ====================================================================
 .
@@ -331,6 +316,46 @@ subsequently appear in an equation.
 .
 .
 .\" ====================================================================
+.SS Primitives
+.\" ====================================================================
+.
+.I @g@eqn
+supports without alteration the AT&T
+.I eqn \" AT&T
+primitives
+.BR above ,
+.BR back ,
+.BR bar ,
+.BR bold ,
+.BR define ,
+.BR down ,
+.BR fat ,
+.BR font ,
+.BR from ,
+.BR fwd ,
+.BR gfont ,
+.BR gsize ,
+.BR italic ,
+.BR left ,
+.BR lineup ,
+.BR mark ,
+.BR matrix ,
+.BR ndefine ,
+.BR over ,
+.BR right ,
+.BR roman ,
+.BR size ,
+.BR sqrt ,
+.BR sub ,
+.BR sup ,
+.BR tdefine ,
+.BR to ,
+.BR under ,
+and
+.BR up .
+.
+.
+.\" ====================================================================
 .SS "New primitives"
 .\" ====================================================================
 .
@@ -685,6 +710,19 @@ picture.
 .SS "Extended primitives"
 .\" ====================================================================
 .
+.I @g@eqn
+recognizes an
+.RB \[lq] on \[rq]
+argument to the
+.B delim
+primitive specially;
+restoring any delimiters that have been previously disabled with
+.RB \[lq] "delim off" \[rq].
+.
+If delimiters haven't been specified,
+neither of these commands have effect.
+.
+.
 .TP
 .BI col\~ n\~\c
 .BR {\~ .\|.\|.\& \~}
@@ -1204,22 +1242,110 @@ Remove definition of
 making it undefined.
 .
 .
-.LP
-Besides the macros mentioned above,
-the following definitions are available:
-.BR Alpha ,
-.BR Beta ,
-\&.\|.\|.,
-.B Omega
-(this is the same as
-.BR ALPHA ,
-.BR BETA ,
-\&.\|.\|.,
-.BR OMEGA ),
-.B ldots
-(three dots on the baseline),
+.\" ====================================================================
+.SS "Predefined macros"
+.\" ====================================================================
+.
+.I @g@eqn
+supports the predefined macros offered by AT&T
+.I eqn:
+.BR and ,
+.BR approx ,
+.BR arc ,
+.BR cos ,
+.BR cosh ,
+.BR del ,
+.BR det ,
+.BR dot ,
+.BR dotdot ,
+.BR dyad ,
+.BR exp ,
+.BR for ,
+.BR grad ,
+.BR half ,
+.BR hat ,
+.BR if ,
+.BR inter ,
+.BR Im ,
+.BR inf ,
+.BR int ,
+.BR lim ,
+.BR ln ,
+.BR log ,
+.BR max ,
+.BR min ,
+.BR nothing ,
+.BR partial ,
+.BR prime ,
+.BR prod ,
+.BR Re ,
+.BR sin ,
+.BR sinh ,
+.BR sum ,
+.BR tan ,
+.BR tanh ,
+.BR tilde ,
+.BR times ,
+.BR union ,
+.BR vec ,
+.BR == ,
+.BR != ,
+.BR += ,
+.BR \-> ,
+.BR <\- ,
+.BR << ,
+.BR >> ,
 and
-.BR dollar .
+.RB \[lq] .\|.\|. \[rq].
+.
+The lowercase classical Greek letters are available as
+.BR alpha ,
+.BR beta ,
+.BR chi ,
+.BR delta ,
+.BR epsilon ,
+.BR eta ,
+.BR gamma ,
+.BR iota ,
+.BR kappa ,
+.BR lambda ,
+.BR mu ,
+.BR nu ,
+.BR omega ,
+.BR omicron ,
+.BR phi ,
+.BR pi ,
+.BR psi ,
+.BR rho ,
+.BR sigma ,
+.BR tau ,
+.BR theta ,
+.BR upsilon ,
+.BR xi ,
+and
+.BR zeta .
+.
+Obtain their uppercase forms by spelling these names with an initial
+capital letter or in full capitals,
+as in
+.B Alpha
+or
+.BR ALPHA .
+.
+.
+.P
+GNU
+.I eqn \" GNU
+further defines the macros
+.BR cdot ,
+.B cdots
+(see above),
+.BR dollar ,
+which sets a dollar sign,
+.BR ldots ,
+which sets three dots on the baseline,
+and
+.BR utilde .
 .
 .
 .\" ====================================================================
@@ -1520,6 +1646,46 @@ See section \[lq]Bugs\[rq] below for translation limits 
specific to
 .SH Bugs
 .\" ====================================================================
 .
+Names of macros and primitives must be quoted anywhere they occur in
+.I eqn \" generic
+input if they are to be interpreted by
+.IR troff . \" generic
+.
+These names,
+particularly short ones like
+.RB \[lq] pi \[rq]
+and
+.RB \[lq] PI \[rq],
+can collide with
+.I troff \" generic
+identifiers.
+.
+For instance,
+the
+.I eqn \" generic
+command
+.
+.RS
+.EX
+gfont PI
+.EE
+.RE
+.
+does not select
+.IR groff 's
+Palatino italic font for the \[lq]global\[rq] equation face;
+you must use
+.
+.RS
+.EX
+gfont "PI"
+.EE
+.RE
+.
+instead.
+.
+.
+.P
 Inline equations are set at the point size that is current at the
 beginning of the input line.
 .