Re: [dev-context] \rm in pmod, bmod, etc

20 Feb 2007


      On Tue, 20 Feb 2007, Hans Hagen wrote:
...
Aditya Mahajan wrote:
...
On Sat, 3 Feb 2007, Taco Hoekwater wrote:
...
It is cleaner when renamed a little:
Taco Hoekwater wrote:
...
\def\binrel@#1%
\def\preparebinrel#1%
...
{\begingroup
    \setbox0=\hbox
       {\thinmuskip 0mu
        \medmuskip -1mu
        \thickmuskip -1mu
        \setbox2=\hbox{$#1\mathsurround0pt$}%
        \kern -wd2
        ${}#1{}\mathsurround0pt$}%
    \edef\@tempa
      {\endgroup
       \let\noexpand\binrel@@
\let\noexpand\currentbinrel
...
\ifdim\wd0<0pt
         \mathbin
       \else \ifdim\wd0>\z@
          \mathrel
       \else
          \relax
       \fi\fi }%
    \@tempa  }
And:
\unexpanded\def\overset#1#2%
  {\preparebinrel{#2}%
   \currentbinrel{\mathop{\kern\z@#2}\limits^{#1}}}
There was another request (although misguided) for overset in the mailing 
list today. I think that the following macros can go into the core: (Taco's 
version, with a typo corrected).
%D \macros{overset, underset}
%D
%D The macros \type{\overset} and \type{\underset} are provided by
%D \AMS\ packages in \LATEX. These macro allows you to place a symbol
%D above or below another symbol, irrespective of whether the other
%D symbol is a relation or something else, and without influencing the
%D spacing.  For most cases there is a better way to do such things
%D (declaring a math command with limop option, or using accents), but
%D occasionally these macros can be useful, for example
%D
%D \startbuffer
%D \startformula
%D \overset{*}{X} \underset{*}{X}
%D \stopformula
%D \stopbuffer
%D \typebuffer \getbuffer
%D
%D Use these macros sparingly. Remember, \TEX\ was designed for
%D mathematics, so there is usually a proper method for typesetting
%D common math notation.
%D These macros are a clearer version of \type{\binrel@} and
%D \type{\binrel@@} macros in \AMSTEX\ packages.
\def\preparebinrel#1%
    {\begingroup
     \setbox0=\hbox
        {\thinmuskip 0mu
         \medmuskip -1mu
         \thickmuskip -1mu
         \setbox2=\hbox{$#1\mathsurround0pt$}%
         \kern-\wd2
         ${}#1{}\mathsurround0pt$}%
     \edef\@tempa
       {\endgroup
        \let\noexpand\currentbinrel
        \ifdim\wd0<0pt
          \mathbin
        \else \ifdim\wd0>\z@
           \mathrel
        \else
           \relax
        \fi\fi}%
     \@tempa}
ok, added in the following disguise:
\def\preparebinrel#1%
{\begingroup
 \setbox\scratchbox\hbox
   {\thinmuskip   0mu
    \medmuskip   -1mu
    \thickmuskip -1mu
    \setbox\scratchbox\hbox{$#1\mathsurround\zeropoint$}%
    \kern-\wd\scratchbox
    ${}#1{}\mathsurround\zeropoint$}%
 \expanded
   {\endgroup
    \let\noexpand\currentbinrel
    \ifdim\wd\scratchbox<\zeropoint
      \mathbin
    \else\ifdim\wd\scratchbox>\zeropoint
      \mathrel
    \else
      \relax
    \fi\fi}}
Ah! So that is why \expanded is useful.

Thanks,
Aditya