% File: DIATOP.TEX (c) Christina Thiele, Ottawa. (from TeXniques 5)
% Tested by Peter J. Olivier. Last change: 4th August 1988.
%
\def\diatop[#1|#2]{{\leavevmode\setbox1=\hbox{{#1{}}}\setbox2=\hbox{{#2{}}}%
    \dimen0=\ifdim\wd1>\wd2\wd1\else\wd2\fi%
    \dimen1=\ht2\advance\dimen1by-1ex%
    \setbox1=\hbox to1\dimen0{\hss#1\hss}%
    \rlap{\raise1\dimen1\box1}%
    \hbox to1\dimen0{\hss#2\hss}}}%