andreas-bauer

\documentclass{standalone}

\usepackage{amsmath,amssymb}

\usepackage{charter}
\usepackage[charter]{mathdesign}

%\font\nullfont=cmr10

andreas-bauer

% Just to add colors and changebars on modified parts after the definition of a condition. Can be removed in the final version
\usepackage{etoolbox}
\newtoggle{showrevisions}

\toggletrue{showrevisions}
%\togglefalse{showrevisions}

\iftoggle{showrevisions}{%
\usepackage{xcolor}
\usepackage{changebar}