\documentclass{ppex}
\nonstopmode
\usepackage [all,2cell]{xy}
\pagestyle{empty}
\setlength\textwidth{183.0pt}
\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage [all,2cell]{xy}
\UseTwocells
\[
\xymatrix{L\rtwocell^u_d & R}
\]
\end{document}