[groff] 11/11: groff_char(7): Further clarify \(rn and similar.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 51256edb50fbadd650f6ed8914f443bd77723ef3
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon May 10 14:42:56 2021 +1000

    groff_char(7): Further clarify \(rn and similar.
    
    Move discussion of \(rn's relationship with \(sr, \[radicalex], and
    \[sqrt] from subsection "Rules and lines" to "Mathematical symbols".
    Change part of \[rn]'s description from "root extension" to "radical
    extension".  Per Ossanna's 1976 version of CSTR #54, "rn" means "root en
    extension".  Explaining that doesn't seem to pay much of a dividend.
    More explicitly note different (potential) metrics of \[sr], \[rn], and
    \[radicalex] on one hand (running text) and \[sqrt] and \[sqrtex] on the
    other (equations).
---
 man/groff_char.7.man | 48 +++++++++++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/man/groff_char.7.man b/man/groff_char.7.man
index 561c611..d3ecf49 100644
--- a/man/groff_char.7.man
+++ b/man/groff_char.7.man
@@ -1354,24 +1354,8 @@ namely a rule of one-half em.
 .
 .
 .P
-In AT&T
-.IR troff ,
-.B \[rs](rn
-served as the horizontal extension of the radical
-(square root)
-sign,
-.BR \[rs](sr .
-.
-In
-.IR groff ,
-use
-.B \[rs][radicalex]
-instead of
 .B \[rs][rn]
-for continuation of the radical sign
-.BR \[rs][sqrt] .
-.
-See subsection \[lq]Mathematical symbols\[rq] below.
+also appears in subsection \[lq]Mathematical symbols\[rq] below.
 .
 .
 .TS
@@ -1383,7 +1367,7 @@ _
 \[br]  \e[br]  u2502   box rule +
 \&_    \&_     u005F   underscore, low line +
 \[ul]  \e[ul]  u005F   underscore, low line +
-\[rn]  \e[rn]  u203E   root extension, overline +
+\[rn]  \e[rn]  u203E   radical extension, overline +
 \[ru]  \e[ru]  ---     baseline rule +
 \[bb]  \e[bb]  u00A6   broken bar
 \[sl]  /       u002F   slash, solidus +
@@ -1526,6 +1510,31 @@ and equals signs.
 Whether these variants differ in appearance or spacing will depend on
 the device and font selected.
 .
+.P
+In AT&T
+.IR troff ,
+.B \[rs](rn
+served as the horizontal extension of the radical
+(square root)
+sign,
+.BR \[rs](sr .
+.
+In
+.IR groff ,
+you can use
+.B \[rs][radicalex]
+instead of
+.B \[rs][rn]
+for continuation of the radical sign
+.BR \[rs][sr] ;
+these have text metrics.
+.
+.B \[rs][sqrt]
+and
+.B \[rs][sqrtex]
+are their counterparts with mathematical spacing.
+.
+.
 .TS
 l l l lx.
 Output Input   Unicode Notes
@@ -1596,8 +1605,9 @@ _
 \[coproduct]   \e[coproduct]   u2210   coproduct ***
 \[gr]  \e[gr]  u2207   gradient +
 \[sr]  \e[sr]  u221A   radical sign, square root +
-\[sqrt]        \e[sqrt]        u221A   radical sign, square root ***
+\[rn]  \e[rn]  u203E   radical extension, overline +
 \[radicalex]   \e[radicalex]   ---     radical extension
+\[sqrt]        \e[sqrt]        u221A   radical sign, square root ***
 \[sqrtex]      \e[sqrtex]      ---     radical extension ***
 
 \[lc]  \e[lc]  u2308   left ceiling +