--- a/tphols-2011/ROOT.ML	Mon Jan 24 11:29:55 2011 +0000
+++ b/tphols-2011/ROOT.ML	Tue Jan 25 12:14:31 2011 +0000
@@ -2,4 +2,4 @@
   no_document use_thys ["This_Theory1", "This_Theory2"];
   use_thys ["That_Theory1", "That_Theory2", "That_Theory3"];
 *)
-use_thys ["../Myhill"];;
+  use_thys ["../Prefix_subtract", "../Myhill"];