more literal appearance of antiqopen/antiqclose;

--- a/doc-src/IsarImplementation/style.sty	Sun Nov 07 16:39:03 2010 +0100
+++ b/doc-src/IsarImplementation/style.sty	Sun Nov 07 22:26:25 2010 +0100
@@ -24,6 +24,9 @@
 
 \renewcommand{\isadigit}[1]{\isamath{#1}}
 
+\renewcommand{\isaantiqopen}{\isasymlbrace}
+\renewcommand{\isaantiqclose}{\isasymrbrace}
+
 \newenvironment{mldecls}{\par\noindent\begingroup\footnotesize\def\isanewline{\\}\begin{tabular}{l}}{\end{tabular}\smallskip\endgroup}
 
 \isafoldtag{FIXME}