\documentclass{ppex} \nonstopmode \usepackage [arrow,matrix,tips]{xy} \pagestyle{empty} \setlength\textwidth{207.0pt} \begin{document} \ResetPreambleCommands \ReadyForTheFray \usepackage [arrow,matrix,tips]{xy} \[\UseTips \newdir{ >}{!/-5pt/\dir{>}} \xymatrix @=1pc @*[r] @*[o] { & \Sigma^L \ar[rrrr]^{\varphi^r} \ar'[d]'[ddd]_{\varphi^m}[dddd] & & & & \Sigma^R \ar[dddd]^{\varphi^{m^*}} \\ L \ar[ur]^{\lambda^L} & & L_r \ar@{ >->}[ll]_(.32){i_1} \ar[rr]^r & & R \ar[ur]_{\lambda^R} \\ \\ L_m \ar@{ >->}[uu]^{i_2} \ar[dd]_m & & K_{r,m} \ar@{ >->}[ll]_(.3){i_3} \ar@{ >->}[uu]_{i_4} \ar[dd]_<<<->}[uu]_{i_6} \ar[dd]_<<<<{m^*} \\ & \Sigma^G \ar'[r]'[rrr]_{\varphi^{r^*}}[rrrr] & & & & \Sigma^H \\ G \ar[ur]^(.7){\lambda^G} & & G_{r^*} \ar@{ >->}[ll]^{i_5} \ar[rr]_{r^*} & & H \ar@{.>}[ur]_{\lambda^H} }\] \end{document}