<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">\documentclass{ppex}
\nonstopmode
\usepackage {xy}
\pagestyle{empty}
\setlength\textwidth{183.0pt}
\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage {xy}
\[\begin{xy}
 0*{DL};&lt;1cm,1cm&gt;*{UR}**@{-}
 ,&lt;0cm,1cm&gt;*{UL};&lt;1cm,0cm&gt;*{DR}**@{=}
\end{xy}\]
\end{document}
</pre></body></html>