eliminated pointless theory graph (reverting parts of a56eab490f4e): it caused problems with loaded vs. non-loaded node names, e.g. for theory Pure (see also 29bb1ebb188f);
\documentclass[11pt,a4paper]{article}
\usepackage{graphicx,isabelle,isabellesym,latexsym}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{textcomp}
\usepackage[english]{babel}
\usepackage[only,bigsqcap]{stmaryrd}
\usepackage[utf8]{inputenc}
\usepackage{pdfsetup}
\urlstyle{rm}
\isabellestyle{it}
\pagestyle{myheadings}
\begin{document}
\title{Isabelle/HOL --- Higher-Order Logic}
\maketitle
\tableofcontents
\begin{center}
\includegraphics[width=\textwidth,height=\textheight,keepaspectratio]{session_graph}
\end{center}
\newpage
\renewcommand{\setisabellecontext}[1]{\markright{THEORY~``#1''}}
\parindent 0pt\parskip 0.5ex
\input{session}
\pagestyle{headings}
\bibliographystyle{abbrv}
\bibliography{root}
\end{document}