added structure Main (from Main.ML);

--- a/src/HOL/ROOT.ML	Wed Nov 08 13:48:34 2006 +0100
+++ b/src/HOL/ROOT.ML	Wed Nov 08 13:48:35 2006 +0100
@@ -37,6 +37,11 @@
 
 with_path "Integ" use_thy "Main";
 
+structure Main =
+struct
+  val thy = theory "Main"
+end;
+
 path_add "~~/src/HOL/Library";
 
 Goal "True";  (*leave subgoal package empty*)