%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 6-2-42 on page 352.
%% 
%%  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{159.83385pt}
\setlength\parindent{0pt}
\StartShownPreambleCommands
\usepackage{pstricks,pst-node}
\StopShownPreambleCommands
\begin{document}
\begin{pspicture}(4,3)
  \rput[bl](0,0){\rnode{A}{\psframebox{A}}}
  \rput[tr](3,3){\ovalnode{B}{B}}
  \nccurve[angleB=180]{A}{B}
  \rput[bl](1,0){\rnode{C}{\psframebox{C}}}
  \rput[tr](4,3){\ovalnode{D}{D}}
  \nccurve[angleB=180,ncurvA=0.3,ncurvB=1]{C}{D}
\end{pspicture}
\end{document}
