resynchronize isabelle.sty

--- a/doc-src/isabelle.sty	Thu Sep 23 13:25:01 2010 +0200
+++ b/doc-src/isabelle.sty	Thu Sep 23 13:28:53 2010 +0200
@@ -46,8 +46,6 @@
 {\begin{trivlist}\begin{isabellebody}\item\relax}
 {\end{isabellebody}\end{trivlist}}
 
-\newcommand{\isatypewriter}{\fontsize{9pt}{0pt}\tt\renewcommand{\baselinestretch}{1}\setlength{\baselineskip}{9pt}}
-
 \newcommand{\isa}[1]{\emph{\isastyleminor #1}}
 
 \newcommand{\isaindent}[1]{\hphantom{#1}}