%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 7-4-4 on page 481.
%% 
%%  Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert Vo\ss 
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{195.83385pt}
\StartShownPreambleCommands
\usepackage[arrow,matrix,tips]{xy}
\StopShownPreambleCommands
\begin{document}
\[\UseTips
\newdir{ >}{!/-5pt/\dir{>}}
\xymatrix @=1pc @*[r] {
  & \Sigma^L \ar[rrrr]^{\varphi^r}
             \ar'[d]'[ddd]_{\varphi^m}[dddd]
  & & & & \Sigma^R \ar[dddd]^{\varphi^{m^*}}
\\ L   \ar[ur]^{\lambda^L}
  & & L_r \ar@{ >->}[ll]_(.32){i_1} \ar[rr]^r
  & & R \ar[ur]_{\lambda^R}
\\ \\ L_m \ar@{ >->}[uu]^{i_2} \ar[dd]_m
       & & K_{r,m} \ar@{ >->}[ll]_(.3){i_3}
                   \ar@{ >->}[uu]_{i_4}
                   \ar[dd]_<<<<m \ar[rr]^r
       & & R_{m^*} \ar@{ >->}[uu]_{i_6}
\ar[dd]_<<<<{m^*}
\\  & \Sigma^G
          \ar'[r]'[rrr]_{\varphi^{r^*}}[rrrr]
        & & & & \Sigma^H
\\ G \ar[ur]^(.7){\lambda^G}
  & & G_{r^*} \ar@{ >->}[ll]^{i_5}
              \ar[rr]_{r^*}
  & & H \ar@{.>}[ur]_{\lambda^H}
}\]
\end{document}