%% 
%%  A DANTE-Edition example
%% 
%%  Example 16-06-6 on page 256.
%% 
%%  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}
\cnode(0.5,0){.25cm}{root}
\nput[rot=90]{-90}{root}{root}
\cnode*(3,1){4pt}{A}  \nput{130}{A}{A}
\cnode*(3,-1){4pt}{C} \nput{-130}{C}{C}
\psset{nodesep=3pt,shortput=nab,labelsep=10pt}
\ncline{root}{A}^{$x$}\ncline{root}{C}_{$y$}
\ncline{A}{C}\ncput*{$z$}
\end{document}
