Fix markup nits combining \c with font changes.

Some of these were exposed by 3549fd9f7bb9134e84a51e9bf82521b6af87a011.

* contrib/mm/groff_mm.7.man:
    + Replace unnecessary uses of {.B|.I} + \c + roman on the next line
      with {.BR|.IR}, so that more words aren't marked up than intended.
* tmac/groff_ms.7.man:
    + Same.
* src/preproc/eqn/eqn.1.man:
    + Same.
    + Also give a tagged paragraph a tag.
* src/devices/grodvi/grodvi.1.man:
    + Remove no-op escapes from the end of a line.

4 files changed, 33 insertions, 32 deletions

diff --git a/contrib/mm/groff_mm.7.man b/contrib/mm/groff_mm.7.man
index 3aa0d827c..9f03b5a31 100644
--- a/contrib/mm/groff_mm.7.man
+++ b/contrib/mm/groff_mm.7.man
@@ -124,13 +124,13 @@ command:
 .LP
 .I XXX
 is the name of the register,
-.I n\c
-\~is the value to be assigned, and
-.I i\c
-\~is the increment value for auto-increment.
+.IR n \~is
+the value to be assigned, and
+.IR i \~is
+the increment value for auto-increment.
 .
-.I n\c
-\~can have a plus or minus sign as a prefix if an increment
+.IR n \~can
+have a plus or minus sign as a prefix if an increment
 or decrement of the current value is wanted.
 .
 (Auto-increment or auto-decrement occurs if the number register is
@@ -179,10 +179,10 @@ Set the format with
 .
 .
 .LP
-.I R\c
-\~is the name of the register,
-.I c\c
-\~is the format.
+.IR R \~is
+the name of the register,
+.IR c \~is
+the format.
 .
 .RS
 .LP
@@ -208,12 +208,11 @@ A@0, A, B, C, .\|.\|., Z, AA, AB, .\|.\|.
 In
 .BR m@TMAC_M_PREFIX@m ,
 the fonts (or rather, font styles)
-.B R\c
-\~(normal),
-.B I\c
-\~(italic), and
-.B B\c
-\~(bold) are hardwired to font positions
+.BR R \~(normal),
+.BR I \~(italic),
+and
+.BR B \~(bold)
+are hardwired to font positions
 .BR 1 ,
 .BR 2 ,
 and\~\c
@@ -1221,8 +1220,8 @@ directly after\~\c
 .B H
 is ignored.
 .
-.B H\c
-\~takes care of spacing and indentation.
+.BR H \~takes
+care of spacing and indentation.
 .
 .IP
 .B Page ejection before heading
@@ -2305,8 +2304,8 @@ Does not output an empty page if currently at the top of an odd page.
 .BI P\  \fR[\fPtype\fR]\fP
 Begin new paragraph.
 .
-.B P\c
-\~without argument produces left\-justified text,
+.BR P \~without
+argument produces left\-justified text,
 even the first line of the paragraph.
 .
 This is the same as setting
@@ -3907,8 +3906,8 @@ and
 are specified through
 .BR .WA / .WB .
 .
-.I n\c
-\~is the counter, 1-max, and
+.IR n \~is
+the counter, 1-max, and
 .I flag
 is true for the last name.
 .
diff --git a/src/devices/grodvi/grodvi.1.man b/src/devices/grodvi/grodvi.1.man
index fd093bfff..50adbf0e1 100644
--- a/src/devices/grodvi/grodvi.1.man
+++ b/src/devices/grodvi/grodvi.1.man
@@ -275,7 +275,7 @@ mounted at font positions 1 to\ 4.
 The fonts are grouped into families
 .B T
 and
-.B H\ \c
+.B H
 having members in each of these styles:
 .
 .RS
diff --git a/src/preproc/eqn/eqn.1.man b/src/preproc/eqn/eqn.1.man
index 5901dbe37..2d42b64b8 100644
--- a/src/preproc/eqn/eqn.1.man
+++ b/src/preproc/eqn/eqn.1.man
@@ -231,8 +231,8 @@ is when the equation is encountered.
 .TP
 .BI \-p n
 This says that subscripts and superscripts should be
-.I n\~\c
-points smaller than the surrounding text.
+.IR n \~points
+smaller than the surrounding text.
 .
 This option is deprecated.
 .
@@ -313,7 +313,9 @@ Possible types are:
 .
 .RS
 .TP \w'punctuation'u+2n
-an ordinary character such as \[oq]1\[cq] or \[oq]\fIx\fP\[cq];
+ordinary
+an ordinary character such as \[oq]1\[cq] or
+.RI \[oq] x \[cq];
 .
 .TP
 operator
@@ -805,8 +807,8 @@ This sets parameter\~\c
 .I p
 to value\~\c
 .IR n ;
-.I n\~\c
-is an integer.
+.IR n \~is
+an integer.
 .
 For example,
 .
@@ -1133,8 +1135,8 @@ is between 1 and\~9, is replaced by the
 .IR n-th
 argument if the macro is called with arguments;
 if there are fewer than
-.I n\~\c
-arguments, it is replaced by nothing.
+.IR n \~arguments,
+it is replaced by nothing.
 .
 A word containing a left parenthesis where the part of the word
 before the left parenthesis has been defined using the
diff --git a/tmac/groff_ms.7.man b/tmac/groff_ms.7.man
index 53d868a74..5ef7f1ae3 100644
--- a/tmac/groff_ms.7.man
+++ b/tmac/groff_ms.7.man
@@ -517,8 +517,8 @@ The argument
 .I xx
 is either a numeric argument to indicate the
 level of the heading, or
-.I S\ xx\ xx\ \c
-".\|.\|."
+.B S\ \c
+.IR "xx\ xx\ " .\|.\|.\&
 to set the section number explicitly.
 .
 If you specify heading levels out of sequence,