%%
%% An UIT Edition example
%%
%% Example 08-03-9 on page 163.
%%
%% 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\yPh{\vphantom{A}}
\let\ol\overline
\StopShownPreambleCommands
\begin{document}
$\overline{x}+\overline{y}=\overline{z}$\\
$ \ol{x} + \ol{A} = \ol{z} $\\[5pt]
$ \ol{x\yPh} + \ol{A} = \ol{z\yPh} $
\end{document}
