<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}
\[\begin{xy}
  0*=+{l}="l" ;&lt;2cm,8mm&gt;*=+{r}="r" **@{-}
 ,&lt;4mm,10mm&gt;*+{ll} ;&lt;25mm,2mm&gt;*+{rr} **@{--}
 ?!{"r";"l"}*{\oplus}
\end{xy}\]
\end{document}
</pre></body></html>