src/HOL/MicroJava/document/root.tex

tuned

\documentclass[11pt,a4paper]{article}
\usepackage{isabelle,isabellesym,pdfsetup}

\setlength{\parindent}{0cm}
\setlength{\parskip}{0,5ex}

\addtolength{\hoffset}{-1,5cm}
\addtolength{\textwidth}{4cm}
\addtolength{\voffset}{-2cm}
\addtolength{\textheight}{4cm}

\renewcommand{\thesubsection}{\arabic{subsection}}
\renewcommand{\isamarkupheader}[1]{\newpage\subsection{#1}}

\pagestyle{headings}

\begin{document}
\tableofcontents
\newpage
\input{session}
\end{document}