%% 
%%  Example 03-02-8 
%%  Copyright (C) 2016 Herbert Voss
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[]{screxa}
\pagestyle{empty}
\setlength\textwidth{328.62788pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{xcolor}
\def\myRule{{\color{red}%
  \mathchoice{\rule{2pt}{20pt}}{\rule{1pt}{10pt}}%
    {\rule{0.5pt}{5pt}}{\rule{0.25pt}{2.5pt}}\mkern2mu}}
%StopShownPreambleCommands
\begin{document}
\Large
$\myRule\sum\limits_{\myRule i=1}^{\myRule\infty}%
 \myRule\frac{\myRule\sqrt{\myRule i+1}}{\myRule i^2}$
\end{document}
