diff -r 95d6853dec4a -r be361e980acf ProgTutorial/Package/Ind_Extensions.thy
--- a/ProgTutorial/Package/Ind_Extensions.thy	Wed Jul 31 15:44:28 2013 +0100
+++ b/ProgTutorial/Package/Ind_Extensions.thy	Sat Aug 31 08:07:45 2013 +0100
@@ -135,7 +135,7 @@
   form
 
   \begin{isabelle}
-  @{text "rule ::= \<And>xs. As \<Longrightarrow> (\<And>ys. Bs \<Longrightarrow> pred ss)\<^isup>* \<Longrightarrow> pred ts"}
+  @{text "rule ::= \<And>xs. As \<Longrightarrow> (\<And>ys. Bs \<Longrightarrow> pred ss)\<^sup>* \<Longrightarrow> pred ts"}
   \end{isabelle}
 
   where the @{text "As"} and @{text "Bs"} can be any collection of formulae