more efficient Markup_Tree, based on branches sorted by quasi-order;
renamed markup_node.scala to markup_tree.scala and classes/objects accordingly;
Position.Range: produce actual Text.Range;
Symbol.Index.decode: convert 1-based Isabelle offsets here;
added static Command.range;
simplified Command.markup;
Document_Model.token_marker: flatten markup at most once;
tuned;
% extra.sty : Isabelle Manual extra macros for non-Springer version
%
\typeout{Document Style extra. Released 17/2/94, version of 22/8/00}
%%Euro-style date: 20 September 1955
\def\today{\number\day\space\ifcase\month\or
January\or February\or March\or April\or May\or June\or
July\or August\or September\or October\or November\or December\fi
\space\number\year}
%%%Put first chapter on odd page, with arabic numbering; like \cleardoublepage
\newcommand\clearfirst{\clearpage\ifodd\c@page\else
\hbox{}\newpage\if@twocolumn\hbox{}\newpage\fi\fi
\pagenumbering{arabic}}
%%%Ruled chapter headings
\def\@rulehead#1{\hrule height1pt \vskip 14pt \Huge \bf
#1 \vskip 14pt\hrule height1pt}
\def\@makechapterhead#1{ { \parindent 0pt
\ifnum\c@secnumdepth >\m@ne \raggedleft\large\bf\@chapapp{} \thechapter \par
\vskip 20pt \fi \raggedright \@rulehead{#1} \par \nobreak \vskip 40pt } }
\def\@makeschapterhead#1{ { \parindent 0pt \raggedright
\@rulehead{#1} \par \nobreak \vskip 40pt } }