%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel C-01-1 auf Seite 894.
%% 
%%  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{193.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pstricks}
\psset{unit=1.5,fillstyle=solid,fillcolor=gray!20,arrowinset=-4,showpoints=true}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture}[showgrid=true](-0.2,-0.5)(4,2.2)
   \psdot*(1,1) \psdot*(3,1)
   \psbezier{->}(1,1)(0,2)(4,2)(3,1) \psbezier{->}(1,1)(0,0)(4,0)(3,1)
\end{pspicture} \quad
\makeatletter\pst@Verb{%
 /Arrow { CLW mul add dup 2 div /w ED mul dup /h ED mul /a ED { 0 h T 1 -1
 scale } if w neg h moveto 0 0 L w h L w neg a neg rlineto
 0 0 moveto % modification by Denis Girou
 gsave fill grestore } def }\makeatother
\begin{pspicture}[showgrid=true](-0.2,-0.5)(4,2.2)
   \psdot*(1,1) \psdot*(3,1)
   \psbezier{->}(1,1)(0,2)(4,2)(3,1) \psbezier{->}(1,1)(0,0)(4,0)(3,1)
 \end{pspicture}
\end{document}