\documentclass{seminar}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amscd}


\newtheorem{definition}{Definition}
\newtheorem{assumption}{Assumption}
\newtheorem{lemma}{Lemma}
\newtheorem{claim}{Claim}
\newtheorem{proposition}{Proposition}


\begin{document}




\begin{slide}
\begin{center}
\textbf{Example}
\end{center}
\begin{itemize}
\item First point \item Second point \item Third point
\end{itemize}


\end{slide}


\end{document}