src/Doc/System/document/root.tex

prefer lmodern, which produces scalable T1 fonts even with Debian-ized TeXLive;

\documentclass[12pt,a4paper]{report}
\usepackage{lmodern}
\usepackage[T1]{fontenc}
\usepackage{supertabular}
\usepackage{graphicx}
\usepackage{iman,extra,isar,ttbox}
\usepackage[nohyphen,strings]{underscore}
\usepackage{isabelle,isabellesym}
\usepackage{railsetup}
\usepackage{style}
\usepackage{pdfsetup}

\hyphenation{Isabelle}
\hyphenation{Isar}

\isadroptag{theory}

\isabellestyle{literal}

\title{\includegraphics[scale=0.5]{isabelle} \\[4ex] The Isabelle System Manual}

\author{\emph{Makarius Wenzel} and \emph{Stefan Berghofer} \\
  TU M\"unchen}

\makeindex


\begin{document}

\maketitle 
\pagenumbering{roman} \tableofcontents \clearfirst

\input{Basics.tex}
\input{Sessions.tex}
\input{Presentation.tex}
\input{Scala.tex}
\input{Misc.tex}

\begingroup
  \tocentry{\bibname}
  \bibliographystyle{abbrv} \small\raggedright\frenchspacing
  \bibliography{manual}
\endgroup

\tocentry{\indexname}
\printindex

\end{document}