%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 5-14-4 on page 299.
%% 
%%  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{135.83385pt}
\StartShownPreambleCommands
\usepackage{pstricks,pst-node}
\SpecialCoor
\StopShownPreambleCommands
\begin{document}
\begin{pspicture}(3,4)
  \rput[lb](0,2.5){\rnode{A}{\textbf{PSTricks}}
  is \rnode{B}{\textbf{PS}}}
  \rput[lb](0,4){\rnode{C}{Unknown $x$-coordinate}}
  \ncline[nodesep=5pt]{->}{C}{A}
  \ncline[nodesep=5pt]{->}{C}{B}
  \psline[linecolor=red](0,0.5)(3,0.5)
  \psset{linecolor=blue}
  \psline{->}(A)(A|0,0.5)
  \psline{->}(B)(B|0,0.5)
\end{pspicture}
\end{document}