% compatible.tex (as Aug. 1990+ code changes)
% compatability macros for multilingual and extened TeX 2.992 plus
% assumes the existence of \charsublist 
% mods : \c@  changed to \@c@                                     --bg 11/30/92
%        \@c@@ was erroneously mispelled \@c@                     --bg 04/20/93
%        apply \c mods from MJF -- July 14, 92                    --bg 08/19/93
%        add \j def for non french language (noted by R. Lemieux).--bg 01/13/94


% #1 -- extended character to be exchanged 
% #2 -- accent macro invocation letter 
% #3 -- base character for this code

\def\csubinverse #1#2#3{\expandafter\def\csname #2#3\endcsname{#1}}
                        
\catcode`\@=11
\def\i{^^P}
\def\j{^^Q}  % \j   % appropriate character subsitution for patterns

% ... test case 

\def\'#1{{\expandafter\ifx\csname @ac@#1\endcsname\relax
           {\accent19 #1}\else\csname @ac@#1\endcsname\fi}}
\def\`#1{{\expandafter\ifx\csname @gr@#1\endcsname\relax
           {\accent18 #1}\else\csname @gr@#1\endcsname\fi}}
\def\v#1{{\expandafter\ifx\csname @v@#1\endcsname\relax
           {\accent20 #1}\else\csname @v@#1\endcsname\fi}}
\let\^^_=\v

\def\u#1{{\expandafter\ifx\csname @u@#1\endcsname\relax
           {\accent21 #1}\else\csname  @u@#1\endcsname\fi}}
\let\^^S=\u

\def\=#1{{\expandafter\ifx\csname @eq@#1\endcsname\relax
           {\accent22 #1}\else\csname @eq@#1\endcsname\fi}}
\def\^#1{{\expandafter\ifx\csname @hat@#1\endcsname\relax
           {\accent94 #1}\else\csname @hat@#1\endcsname\fi}}
\let\^^D=\^
\def\.#1{{\expandafter\ifx\csname @dot@#1\endcsname\relax
           {\accent95 #1}\else\csname @dot@#1\endcsname\fi}}
\def\H#1{{\expandafter\ifx\csname @H@#1\endcsname\relax
           {\accent'175 #1}\else\csname @H@#1\endcsname\fi}}
\def\~#1{{\expandafter\ifx\csname @til@#1\endcsname\relax
           {\accent'176 #1}\else\csname @til@#1\endcsname\fi}}
\def\"#1{{\expandafter\ifx\csname @um@#1\endcsname\relax
           {\accent'177 #1}\else\csname @um@#1\endcsname\fi}}


%\let\@c@@=\c
% recursive definition of \c does not work when letter is not in font
% MJF -- July 14, 92

\def\@c@@#1{\setbox\z@\hbox{#1}\ifdim\ht\z@=1ex\accent24 #1%
  \else{\ooalign{\unhbox\z@\crcr\hidewidth\char24\hidewidth}}\fi}

\def\c#1{{\expandafter\ifx\csname @c@#1\endcsname\relax
           \@c@@{#1}\else\csname @c@#1\endcsname\fi}}
% fix Justin Bur ... 1 Oct. 90



% test form for accents ... 
\def\aa{\accent23a}