src/ZF/ex/CoUnit.thy

--- a/src/ZF/ex/CoUnit.thy	Fri Jun 17 11:35:35 2005 +0200
+++ b/src/ZF/ex/CoUnit.thy	Fri Jun 17 16:12:49 2005 +0200
@@ -6,7 +6,7 @@
 
 header {* Trivial codatatype definitions, one of which goes wrong! *}
 
-theory CoUnit = Main:
+theory CoUnit imports Main begin
 
 text {*
   See discussion in: L C Paulson.  A Concrete Final Coalgebra Theorem