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%%  Ein Beispiel der DANTE-Edition
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%%  Beispiel 09-06-1 auf Seite 414.
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%%  Copyright (C) 2011 Herbert Voss
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%%  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.
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%%  See http://www.latex-project.org/lppl.txt for details.
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\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{190.324pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\setlength\arraycolsep{1.4pt}
\StopShownPreambleCommands
\begin{document}
\[ z=f(x,y) \rightarrow
  \begin{array}[b]{|rl|} y &=f(x)\\ y &= 3x^2     \end{array} \rightarrow
  \begin{array}[c]{|rl|} x &=f(u)\\ x &= \sqrt{u} \end{array} \rightarrow
  \begin{array}[t]{|rl|} v &=f(w)\\ v &= u^2-w^3  \end{array} \rightarrow
  f(w) \]
\end{document}