--- a/preamble.tex	Fri Jun 05 23:02:55 2009 +0000
+++ b/preamble.tex	Sun Jun 07 00:51:00 2009 +0000
@@ -10,6 +10,8 @@
 \usepackage[all,color]{xy}
 %\fi
 
+\usepackage{leftidx}
+
 \SelectTips{cm}{}
 % This may speed up compilation of complex documents with many xymatrices.
 %\CompileMatrices