%% 
%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 04-08-11 auf Seite 59.
%%  Copyright (C) 2018 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[10pt]{screxa}
\pagestyle{empty}
\setlength\textwidth{170.40707pt}
\AtBeginDocument{\setlength\parindent{0pt}}
%StartShownPreambleCommands
\usepackage{setspace}
\newenvironment{Array}[2][1]
  {\setstretch{#1}\array{#2}}
  {\endarray}
%StopShownPreambleCommands
\begin{document}
\[ \begin{Array}[0.75]{|ccc|}
a &=& b\\ 1 &=& y\\ X &=& z
\end{Array} \]

Text $\begin{Array}[2]{|ccc|}
a &=& b\\ 1 &=& y\\ X &=& z
\end{Array}$ Text
\end{document}