%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 6-3-19 on page 375.
%% 
%%  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{207.83385pt}
\StartShownPreambleCommands
\usepackage{pstricks,pst-tree}    \SpecialCoor
\StopShownPreambleCommands
\begin{document}
  \psset{nodesep=5pt}
  \pstree[treemode=R,levelsep=3cm]{%
      \rnode{A}{}\Tr{\rnode{A}{}Friedrich Wilhelm}}{%
          \pstree{\Tr{Friedrich I.}}{%
              \Tr{\rnode{C}{}Friedrich Wilhelm I.}  \Tr{Friedrich}}
      \pstree{\Tr{\rnode{B}{}Albrecht Friedrich}}{%
          \Tr{Wilhelm Heinrich}  \Tr{Friedrich}}}
  \psset{arrowscale=2,linewidth=0.2pt}
  \pcline[linestyle=dashed](A)(A|0,-1)   \pcline[linestyle=dashed](B)(B|0,-1)
  \pcline[linestyle=dashed](C)(C|0,-1)
  \pnode(A|0,-.8){A1}\pnode(B|0,-.8){A2} \ncline[arrows=<->]{A1}{A2}
  \ncput*{\texttt{levelsep}}
  \pnode(C|0,-.8){A3}  \ncline[arrows=<->]{A2}{A3}\ncput*{\texttt{levelsep}}
\end{document}