--- a/src/HOL/Library/Product_ord.thy Mon Dec 10 11:24:08 2007 +0100
+++ b/src/HOL/Library/Product_ord.thy Mon Dec 10 11:24:09 2007 +0100
@@ -6,7 +6,7 @@
header {* Order on product types *}
theory Product_ord
-imports Main
+imports PreList
begin
instantiation "*" :: (ord, ord) ord