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%%  Ein Beispiel der DANTE-Edition
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%%  7. Auflage
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%%  Beispiel 32-03-18 auf Seite 734.
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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.
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%% ====
% Show page(s) 1
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\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{193.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-optic}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-5,-3)(5,3)
\pnodes(-1,-2.5){A}(1,-2.5){B}(1,2.5){C}(-1,2.5){D}
\uput[-135](A){A}\uput[-45](B){B}\uput[45](C){C}\uput[135](D){D}
\pspolygon[fillcolor=lightgray,fillstyle=solid,linecolor=blue](A)(B)(C)(D)
\refractionRay(-3,-3)(-2,-2)(D)(A){1}{1.5}{END}%    1.
\psset{linecolor=red,linewidth=2pt,arrowsize=5pt,arrows=->}
\arrowLine(-3,-3)(END){2}  \ABinterCD(END)(END')(C)(B){Out}
\arrowLine(END)(Out){1}    \refractionRay(END)(Out)(C)(B){1.5}{1}{Q}
\arrowLine(Q)(Q'){1}       \psOutLine[length=2](Q)(Q'){End}
\refractionRay(-3,0)(-2,0)(A)(D){1}{1.5}{END}%      2.
\psset{linecolor=green,linewidth=2pt,arrowsize=5pt,arrows=->}
\arrowLine(-3,0)(END){2}  \ABinterCD(END)(END')(C)(B){Out}
\arrowLine(END)(Out){1}   \refractionRay(END)(Out)(C)(B){1.5}{1}{Q}
\arrowLine(Q)(Q'){1}      \psOutLine[length=2](Q)(Q'){End}
\refractionRay(-3,3)(-2,2)(D)(A){1}{1.5}{END}%      3.
\psset{linecolor=blue,linewidth=2pt,arrowsize=5pt,arrows=->}
\arrowLine(-3,3)(END){2}   \ABinterCD(END)(END')(C)(B){Out}
\arrowLine(END)(Out){1}    \refractionRay(END)(Out)(C)(B){1.5}{1}{Q}
\arrowLine(Q)(Q'){1}       \psOutLine[length=2](Q)(Q'){End}
\end{pspicture}
\end{document}