[groff] 12/41: [docs]: Tweak `|` operator discussion.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 0e1d75c6f30073ff2ed7eb6b2a926171deb299e4
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Tue Mar 15 20:28:38 2022 +1100

    [docs]: Tweak `|` operator discussion.
    
    * doc/groff.texi (Numeric Expressions): Some of the language still
      itched; at last I found an alternative wording to discuss positions
      and distances "on the _input_ line" [sic], which seems conceptually
      slippery.  An input line is a stream of tokens, to which concepts like
      position and distance apply poorly, except perhaps in the text editors
      used to compose them.  What is meant is that, in many situations, we
      can associate an input token with a drawing position, from which we
      can establish a metric.
    
    * man/groff.7 (Numeric expressions): Sync section title and `|` material
      with corresponding node in our Texinfo manual.
---
 doc/groff.texi  |  7 ++++---
 man/groff.7.man | 22 ++++++++++++++++------
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/doc/groff.texi b/doc/groff.texi
index 76cc0a65..b71fe16d 100644
--- a/doc/groff.texi
+++ b/doc/groff.texi
@@ -5892,9 +5892,10 @@ decrements.
 @c "motion" and "operators" already indexed above
 Similarly, a leading @samp{|} operator indicates a motion relative not
 to the current position but to a boundary.  For horizontal motions, the
-measurement specifies a distance relative to what was formatted at the
-beginning of the @emph{input} line.  By default, tab stops are reckoned
-in this way.  Most escape sequences do not; @c XXX: Which ones do?
+measurement specifies a distance relative to the drawing position at the
+beginning of the @emph{input} line.  By default, tab stops reckon
+measurements in this way.  Most escape sequences do not;
+@c XXX: Which ones do?
 @samp{|} tells them to do so.
 
 @Example
diff --git a/man/groff.7.man b/man/groff.7.man
index 6afeb61e..5e17bc74 100644
--- a/man/groff.7.man
+++ b/man/groff.7.man
@@ -660,7 +660,7 @@ registers exercise color support.
 .
 .
 .\" ====================================================================
-.SH "Numerical expressions"
+.SH "Numeric expressions"
 .\" ====================================================================
 .
 A
@@ -850,13 +850,23 @@ sequence by the following expression.
 Interpret the following expression as a motion relative not to the
 current position but to a boundary.
 .
-For vertical movements,
-it specifies a distance from the top of the page
-(or diversion);
-for horizontal ones,
-from the beginning of the
+For horizontal motions,
+the measurement specifies a distance relative to the drawing position at
+the beginning of the
 .I input
 line.
+.
+By default,
+tab stops reckon measurements in this way.
+.
+Most escape sequences do not; \" XXX: Which ones do?
+.B |
+tells them to do so.
+.
+For vertical movements,
+this operator specifies a distance from the first text baseline on the
+page or in the diversion,
+using the current vertical spacing.
 .RE
 .
 .