--- a/src/HOL/Option.thy Wed Sep 03 00:06:25 2014 +0200
+++ b/src/HOL/Option.thy Wed Sep 03 00:06:26 2014 +0200
@@ -5,7 +5,7 @@
header {* Datatype option *}
theory Option
-imports BNF_Least_Fixpoint Old_Datatype Finite_Set
+imports BNF_Least_Fixpoint Finite_Set
begin
datatype_new 'a option =