--- a/Nominal/NewFv.thy	Tue May 18 14:40:05 2010 +0100
+++ b/Nominal/NewFv.thy	Wed May 19 12:43:38 2010 +0100
@@ -290,4 +290,21 @@
 end
 *}
 
+(**************************************************)
+
+datatype foo =
+  C1 nat
+| C2 foo int
+
+(*
+ML {* 
+fun mk_body descr sorts fv_ty_map dtyp =
+let
+  val nth_dtyp_constr_tys descr sorts
+in
+  true
 end
+*}
+*)
+
+end