%======================= main.tex ===========================================
\documentstyle{slides}
%\input{mssymb}
%\newtheorem{exam}{Example}[section]
%\newtheorem{prop}{Proposition}[section]  
%\newtheorem{lem}{Lemma}[section]  
%\newtheorem{thm}{Theorem}[section]  
%\newtheorem{cor}{Corollary}[section]  
\newcommand{\trace}{\mbox{trace}}
\newcommand{\diag}{\mbox{diag}}
\newcommand{\Diag}{\mbox{Diag}}
\newcommand{\conv}{\mbox{conv}}
\pagestyle{plain}
\begin{document}
test
\blackandwhite{example}
\end{document}
