%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 15-07-4 auf Seite 286.
%% 
%%  Copyright (C) 2016 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
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%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{193.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-node}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-0.5,0)(3.5,3) \Huge
  \cnode(1,3){4pt}{A}
  \rput[B](0,0){\Rnode{B}{A}}
  \rput[B](2,0){\Rnode{C}{a}}
  \psset{angleA=90,YnodesepA=1ex}
  \nccurve[angleB=-135]{<-}{B}{A}
  \nccurve[angleB=-45]{<-}{C}{A}
\end{pspicture}
\end{document}