added missing quantifier

--- a/src/HOL/Tools/ATP/atp_translate.ML	Tue Dec 13 14:55:42 2011 +0100
+++ b/src/HOL/Tools/ATP/atp_translate.ML	Tue Dec 13 14:55:42 2011 +0100
@@ -1905,7 +1905,8 @@
              AConn (AImplies,
                     [type_class_formula type_enc subclass ty_arg,
                      type_class_formula type_enc superclass ty_arg])
-             |> close_formula_universally,
+             |> mk_aquant AForall
+                          [(tvar_a_name, atype_of_type_vars type_enc)],
              isabelle_info format introN, NONE)
   end