%% 
%%  Example 02-02-1 
%%  Copyright (C) 2016 Herbert Voss
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{screxa}
\pagestyle{empty}
\setlength\textwidth{158.31393pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{amsmath}
%StopShownPreambleCommands
\begin{document}
\begin{gather}
i_{11}=0.25\\
i_{21}=\frac{1}{3}i_{11}\nonumber \\
i_{31}=0.33i_{22}
\end{gather}
\end{document}
