--- a/ProgTutorial/Package/Ind_General_Scheme.thy	Mon Apr 30 12:36:32 2012 +0100
+++ b/ProgTutorial/Package/Ind_General_Scheme.thy	Mon Apr 30 14:43:52 2012 +0100
@@ -197,7 +197,7 @@
 \begin{figure}[p]
 \begin{minipage}{\textwidth}
 \begin{isabelle}*}  
-ML{*(* even-odd example *)
+ML %grayML{*(* even-odd example *)
 val eo_defs = [@{thm even_def}, @{thm odd_def}]
 
 val eo_rules =