%% 
%%  A DANTE-Edition example
%% 
%%  Example 16-06-5 on page 255.
%% 
%%  Copyright (C) 2011 Herbert Voss
%% 
%%  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.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{153.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks,pst-node}

\begin{document}
$\arraycolsep=1.1cm
  \begin{array}{@{}cc@{}}
    \Rnode{a}{(X-A)} & \Rnode{b}{A} \\[1.5cm]
        \Rnode{c}{x} & \Rnode{d}{\tilde{X}}
  \end{array}
  \psset{nodesep=5pt,arrows=->}
  \everypsbox{\scriptstyle}
  \ncline{a}{c}                   \tlput{r}
  \ncline{a}{b}                   \taput{u}
  \ncline[linestyle=dashed]{c}{d} \tbput{b}
  \ncline{b}{d}                   \trput{s}$
\end{document}