Main is implicitly imported via Sublist

--- a/src/HOL/Library/Sublist_Order.thy	Thu Aug 30 13:05:11 2012 +0900
+++ b/src/HOL/Library/Sublist_Order.thy	Thu Aug 30 13:06:04 2012 +0900
@@ -6,9 +6,7 @@
 header {* Sublist Ordering *}
 
 theory Sublist_Order
-imports
-  Main
-  Sublist
+imports Sublist
 begin
 
 text {*