diff -r 7850b4cc1507 -r 9a173a22771c src/HOL/Library/Quotient_Option.thy
--- a/src/HOL/Library/Quotient_Option.thy	Mon Nov 15 14:14:38 2010 +0100
+++ b/src/HOL/Library/Quotient_Option.thy	Mon Nov 15 14:59:21 2010 +0100
@@ -9,7 +9,7 @@
 begin
 
 fun
-  option_rel :: "('a \<Rightarrow> 'a \<Rightarrow> bool) \<Rightarrow> 'a option \<Rightarrow> 'a option \<Rightarrow> bool"
+  option_rel :: "('a \<Rightarrow> 'b \<Rightarrow> bool) \<Rightarrow> 'a option \<Rightarrow> 'b option \<Rightarrow> bool"
 where
   "option_rel R None None = True"
 | "option_rel R (Some x) None = False"