%% 
%%  A DANTE-Edition example
%% 
%%  Example 16-04-8 on page 244.
%% 
%%  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{177.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks-add}

\begin{document}
\begin{pspicture}(4,4.5)
 \cnode*(0,0){2pt}{A}  \cnode*(0.25,0){2pt}{C}
 \cnode*(0.5,0){2pt}{E}\cnode*(0.75,0){2pt}{G}
 \cnode*(2,3){2pt}{B}  \cnode*(2.5,3.5){2pt}{D}
 \cnode*(3,4){2pt}{F}  \cnode*(3.5,4.5){2pt}{H}
 {\psset{arrowscale=2,linearc=0.2,
  linecolor=blue,armA=0.5, angleA=90,angleB=-90}
 \pcdiag[lineAngle=20]{->}(A)(B)
 \pcdiag[lineAngle=20]{->}(C)(D)
 \pcdiag[lineAngle=20]{->}(E)(F)
 \pcdiag[lineAngle=20]{->}(G)(H)}
\end{pspicture}
\end{document}