%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 15-08-10 auf Seite 291.
%% 
%%  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
%% 
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{169.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-node}
\def\psrowhookii{\huge}
%StopShownPreambleCommands
\begin{document}
\psmatrix[colsep=1cm]
    [name=A]A \psspan{3}\\[0pt]
    [name=X] X  & [name=Y] Y  & [name=Z] Z\\
                & [name=B]B
\endpsmatrix
 \psset{nodesep=3pt,arrows=->}
 \ncline{A}{X} \ncline{A}{Y} \ncline{A}{Z}
 \ncline{X}{B} \ncline{Y}{B} \ncline{Z}{B}
\end{document}