adjusted import to changed HOL theory graph

--- a/src/HOL/ex/Numeral.thy	Wed Oct 28 19:09:47 2009 +0100
+++ b/src/HOL/ex/Numeral.thy	Thu Oct 29 08:14:23 2009 +0100
@@ -5,7 +5,7 @@
 header {* An experimental alternative numeral representation. *}
 
 theory Numeral
-imports Int Inductive
+imports Plain Divides
 begin
 
 subsection {* The @{text num} type *}