diff -r b9d9c4540265 -r 6b51117b8955 Nominal/nominal_dt_supp.ML
--- a/Nominal/nominal_dt_supp.ML	Sun Aug 29 00:09:45 2010 +0800
+++ b/Nominal/nominal_dt_supp.ML	Sun Aug 29 00:36:47 2010 +0800
@@ -21,7 +21,8 @@
 let  
   val vs = fresh_args ctxt qtrm
   val rhs = list_comb (qtrm, vs)
-  val lhs = mk_supp (foldl1 HOLogic.mk_prod vs)
+  val lhs = fold (curry HOLogic.mk_prod) vs @{term "()"}
+    |> mk_supp
 in
   mk_supports lhs rhs
   |> HOLogic.mk_Trueprop