%%
%% The LaTeX Companion, 2ed (second printing August 2004)
%%
%% Example 8-3-8 on page 489.
%%
%% Copyright (C) 2004 Frank Mittelbach, Michel Goossens,
%%    Johannes Braams, David Carlisle, and Chris Rowley
%%
%% 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{159.0pt}

\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
\[\begin{array}{ccc}
    S^{\mathcal{W}_\Lambda}\otimes T &
      \stackrel{j}{\longrightarrow}  &
    T                                         \\
    \Big\downarrow                   &   &
    \Big\downarrow\vcenter{%
      \rlap{$\scriptstyle{\mathrm{End}}\,P$}} \\
    (S\otimes T)/I                   & = &
    (Z\otimes T)/J
  \end{array}\]
\end{document}