diff -r d8fbd3fa0375 -r d1fb55c2ed65 src/HOL/Quickcheck.thy
--- a/src/HOL/Quickcheck.thy	Thu Dec 01 22:14:35 2011 +0100
+++ b/src/HOL/Quickcheck.thy	Thu Dec 01 22:14:35 2011 +0100
@@ -16,7 +16,7 @@
 
 subsection {* Catching Match exceptions *}
 
-definition catch_match :: "term list option => term list option => term list option"
+definition catch_match :: "(bool * term list) option => (bool * term list) option => (bool * term list) option"
 where
   [code del]: "catch_match t1 t2 = (SOME t. t = t1 \<or> t = t2)"