\documentclass[dvips]{slides}
\usepackage{portland}
\usepackage{pifont}
\usepackage[dvips]{epsfig}
\newcommand{\R}{{\rm I\!R}}
\newcommand{\SSS}{\scriptscriptstyle}
\def\boldf#1{\hbox{\rlap{$#1$}\kern.4pt{$#1$}}}
%\documentclass[titlepage,12pt]{article}
\usepackage[reqno]{amsmath}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{epsf}
\usepackage{psfig}
\usepackage{epsfig}
\usepackage{url}
\usepackage{verbatim}
\newcommand{\bbeta}{{\boldsymbol\beta}}
\newcommand{\btheta}{{\boldsymbol\theta}}
\newcommand{\bPhi}{{\boldsymbol\Phi}}
\newcommand{\bmu}{\boldsymbol{\mu}}
\newcommand{\bSigma}{{\boldsymbol\Sigma}}
\newcommand{\cN}{{\cal N}}
\newcommand{\cP}{{\cal P}}
\newcommand{\bW}{\mathbf{W}}
\newcommand{\bQ}{\mathbf{Q}}
\newcommand{\bZ}{\mathbf{Z}}
\newcommand{\bS}{\mathbf{S}}
\newcommand{\bT}{\mathbf{T}}
\newcommand{\bz}{{\mathbf z}}
\newcommand{\bx}{{\mathbf x}}
\newcommand{\half}{\textstyle{\frac{1}{2}}}
\newcommand{\real}{\mathbb{R}}

\def\boldf#1{\hbox{\rlap{$#1$}\kern.4pt{$#1$}}}
\newenvironment{essential}{\begin{minipage}[t]{12.4cm}\textwidth=12.2cm\parskip=5mm\vspace{0.2cm}}{\vspace{0.5cm}\end{minipage}}

\newenvironment{tightlist}{
 \vspace*{-1.5em}  %  Too much space after the title!  -laura
  \begin{list}{$\bullet$}{%
    \advance\partopsep by \topsep
    \setlength{\topsep}{0in}
    \setlength{\itemsep}{0in}
    \setlength{\parsep}{0em}
    \setlength{\leftmargin}{1.5em}
    \setlength{\rightmargin}{0in}
    \setlength{\itemindent}{0in}
    \def\tightlist@empty{}
  }
}
{\ifx\tightlist@empty\empty \item[$\circ$] None \fi \end{list}\vspace{1ex}}

\begin{document}
\pagestyle{empty}
\landscape
\include{class21}

\end{document}