%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
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%%  Beispiel 15-06-6 auf Seite 284.
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%%  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}
\cnode(0.5,0){.25cm}{root}
\nput[rot=90]{-90}{root}{Wurzel}
\cnode*(3,1){4pt}{A}  \nput{130}{A}{A}
\cnode*(3,-1){4pt}{C} \nput{-130}{C}{C}
\psset{nodesep=3pt,shortput=nab}
\ncline{root}{A}^{$x$}
\ncline{root}{C}_{$y$}
\ncline{A}{C}\ncput*{$z$}
\end{document}