%% 
%%  An UIT Edition example
%% 
%%  Example 08-02-1 on page 155.
%% 
%%  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
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{177.70511pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\def\tdela{\delimiter"4222378\relax}
\def\tdelb{\delimiter"5223379\relax}
\StopShownPreambleCommands
\begin{document}
$\tdela x-y\tdelb(x+y)=x^2-y^2$
\[ \tdela\sum_{n=0}^\infty
        {1\over2^n}\tdelb^2 = 4  \]
\[ \left\tdela\sum_{n=0}^\infty
   {1\over2^n}\right\tdelb^2 = 4 \]
\end{document}