%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 6-2-25 on page 345.
%% 
%%  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{135.83385pt}
\StartShownPreambleCommands
\usepackage{pstricks,pst-node}
\StopShownPreambleCommands
\begin{document}
\large\rnode{A}{\psframebox{start}}\qquad
\rnode{M}{\psframebox{middle}}\qquad
\rnode{B}{\psframebox{end}}
\ncline{->}{A}{M}\ncline{->}{M}{B}
\ncloop[loopsize=0.9,arm=0.4,linearc=.2,angleB=180]
       {->}{A}{B}
\end{document}
