%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
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%%  Beispiel 32-03-29 auf Seite 740.
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%%  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
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\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{169.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-optexp}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture}[showgrid](0,-0.3)(3,2.3)
  \pnode(0.5,1){A}\pnode(3,1){B}
  \optbox[position=start, optboxsize=0.5 1](A)(B)
  \lens[n=2](A)(B)
  \drawwidebeam[beamwidth=0.2, fillstyle=solid,
     fillcolor=green!40]{1-2}(B)
  \psdot(A)\uput[45](A){A}\psdot(B)\uput[135](B){B}
\end{pspicture}
\end{document}