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%%  An UIT Edition example
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%%  Example 04-11-2 on page 60.
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%%  Copyright (C) 2010 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.
%%
%%  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{153.70511pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
$\begin{array}{r@{\kern1.5pt}c@{\kern1.5pt}c}
    &   & \textrm{factorise}\\
f(x) & = & \underbrace{\overbrace{x^{2}+2x+1}}\\
    &   & \quad\left(x+1\right)^{2}
\end{array}$
\end{document}