\documentclass[12pt]{amsart}

\newcommand{\lra}{\longrightarrow}
\newcommand{\Z}{{\mathbf Z}}
\newcommand{\Q}{{\mathbf Q}}
\newcommand{\R}{{\mathbf R}}
\newcommand{\C}{{\mathbf C}}
\newcommand{\Proj}{{\mathbf P}}
\newcommand{\northpole}{{\mathbf n}}
\renewcommand{\Re}[1]{{\text Re}(#1)}
\renewcommand{\Im}[1]{{\text Im}(#1)}

\include{xy}
\xyoption{all}
\SelectTips{cm}{}
\CompileMatrices

\include{iJSepsf}
\newcommand{\graphillus}[3]{\epsfysize=#1truein
\vbox{\centerline{\epsffile{#2.eps}}\caption{#3}}}

\theoremstyle{plain}
\newtheorem{thm}{Theorem}[section]
\newtheorem{defn}[thm]{Definition}
\newtheorem{prop}[thm]{Proposition}
\newtheorem{lem}[thm]{Lemma}
\newtheorem{cor}[thm]{Corollary}

\begin{document}

\title{Assignment from Chapter 3 of Sipser}
\maketitle

Exercise
\begin{itemize}
\item 3.7 (incorrect description of a TM)
\end{itemize}

Problems
\begin{itemize}
\item 3.12 (another TM variant)
\item 3.15 (closure properties of decidable languages)
\item 3.16 (closure properties of recognizable languages)
\end{itemize}

\end{document}
