lib/texinputs/isabelle.sty

 \chardef\isabackslash=`\\
 
 
 % keyword and section markup
 
-\newcommand{\isacommand}[1]{{\bf #1}}
-\newcommand{\isakeyword}[1]{\/{\bf #1}}
+\newcommand{\isacommand}[1]{\emph{\bf #1}}
+\newcommand{\isakeyword}[1]{\emph{\bf #1}}
 \newcommand{\isabeginblock}{\isakeyword{\{}}
 \newcommand{\isaendblock}{\isakeyword{\}}}
 
 \newcommand{\isapar}[1]{{\par\medskip #1\par\smallskip}}
 \newcommand{\isamarkupheader}[1]{#1}