%% 
%%  An UIT Edition example
%% 
%%  Example 04-01-2 on page 32.
%% 
%%  Copyright (C) 2010 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{201.70511pt}
\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}