--- a/src/HOL/Library/Char_ord.thy Fri Aug 24 20:58:29 2012 +0200
+++ b/src/HOL/Library/Char_ord.thy Sun Aug 26 10:20:26 2012 +0200
@@ -5,7 +5,7 @@
header {* Order on characters *}
theory Char_ord
-imports Product_ord Char_nat Main
+imports Char_nat
begin
instantiation nibble :: linorder