--- a/src/HOL/Nominal/nominal_fresh_fun.ML Tue Mar 09 14:18:06 2010 +0100
+++ b/src/HOL/Nominal/nominal_fresh_fun.ML Tue Mar 09 14:55:25 2010 +0100
@@ -58,7 +58,7 @@
val goal = List.nth(prems_of thm, i-1);
val ps = Logic.strip_params goal;
val Ts = rev (map snd ps);
- fun is_of_fs_name T = Sign.of_sort thy (T, Sign.intern_sort thy ["fs_"^atom_basename]);
+ fun is_of_fs_name T = Sign.of_sort thy (T, [Sign.intern_class thy ("fs_"^atom_basename)]);
(* rebuild de bruijn indices *)
val bvs = map_index (Bound o fst) ps;
(* select variables of the right class *)