lib/texinputs/isabelle.sty

--- a/lib/texinputs/isabelle.sty	Thu Feb 10 20:54:18 2000 +0100
+++ b/lib/texinputs/isabelle.sty	Thu Feb 10 20:54:40 2000 +0100
@@ -8,7 +8,8 @@
 
 % basic environment
 
-\newenvironment{isabellesimple}{\small\tt\slshape\mbox{}}{}
+\newcommand{\isabellesimplestyle}{}
+\newenvironment{isabellesimple}{\small\tt\slshape\isabellesimplestyle\mbox{}}{}
 \newcommand{\isanewline}{\mbox{}\\\mbox{}}
 
 \chardef\isabraceleft=`\{