%%
%% An UIT Edition example
%%
%% Example 09-16-2 on page 181.
%%
%% 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{201.70511pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\usepackage{gauss} \newmatrix{]}{[}{q}
\StopShownPreambleCommands
\begin{document}
$\begin{gmatrix}[q]
1 & 2\\ 3 & 4
\end{gmatrix}$
\end{document}