%% 
%%  An UIT Edition example
%% 
%%  Example 04-06-1 on page 46.
%% 
%%  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{375.57637pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
$math - \mathrm{upright} - \textrm{upright} - \mbox{upright}$
\par\Large
$A^{\mathrm{text}}_{\mathrm{text}}$ \quad $A^{\textrm{text}}_{\textrm{text}}$\quad
$A^{\mbox{text}}_{\mbox{text}}$     \quad $A^{\textnormal{text}}_{\textnormal{text}}$
\end{document}