added AND, IS, WHERE symbols;

--- a/doc-src/isar.sty	Mon Apr 28 14:22:42 2008 +0200
+++ b/doc-src/isar.sty	Mon Apr 28 14:41:32 2008 +0200
@@ -24,6 +24,10 @@
 \newcommand{\indexisarmethof}[2]{\indexdef{#1}{method}{#2}}
 \newcommand{\indexisarattof}[2]{\indexdef{#1}{attribute}{#2}}
 
+\newcommand{\isasymAND}{\isakeyword{and}}
+\newcommand{\isasymIS}{\isakeyword{is}}
+\newcommand{\isasymWHERE}{\isakeyword{where}}
+
 \newcommand{\isarkeyword}[1]{{\mathord{\mathbf{#1}}}}
 \newcommand{\isarcmd}[1]{\isarkeyword{#1}}
 \newcommand{\isartrans}[2]{#1 \mathbin{\,\to\,} #2}