<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 [all]{xy}
\pagestyle{empty}
\setlength\textwidth{207.0pt}
\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage [all]{xy}
\[
\xymatrix{
 A &amp; *+[F]{\sum_{i=n}^m {i^2}} \\
   &amp; {\bullet} &amp; D \ar[ul]
}\]
\end{document}
</pre></body></html>