%% 
%%  Example 01-20-1 
%%  Copyright (C) 2017 Herbert Voss
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{screxa}
\pagestyle{empty}
\setlength\textwidth{110.31393pt}

%StartShownPreambleCommands

%StopShownPreambleCommands
\begin{document}
\begin{equation}
{m+1 \choose n}={m \choose n}+{m \choose k-1}
\end{equation}
\end{document}
