--- a/ProgTutorial/Intro.thy	Thu Oct 22 14:08:23 2009 +0200
+++ b/ProgTutorial/Intro.thy	Sun Oct 25 15:26:03 2009 +0100
@@ -27,7 +27,7 @@
   then this tutorial is for you. It will guide you through the first steps of
   Isabelle programming, and also explain tricks of the trade. We also hope
   the tutorial will encourage researchers to play with Isabelle and implement
-  new ideas. The sources of Isabelle can look intimidating, but beginners 
+  new ideas. The source code of Isabelle can look intimidating, but beginners 
   can get by with knowledge of only a small number functions and a few basic
   coding conventions.