--- a/Nominal/Abs.thy	Thu Mar 11 19:43:50 2010 +0100
+++ b/Nominal/Abs.thy	Thu Mar 11 20:49:31 2010 +0100
@@ -736,7 +736,7 @@
 apply(simp add: inj_on_def)
 done
 
-lemma
+lemma supp_atom_image:
   fixes as::"'a::at_base set"
   shows "supp (atom ` as) = supp as"
 apply(simp add: supp_def)
@@ -745,6 +745,12 @@
 apply(simp add: atom_image_cong)
 done
 
+lemma swap_atom_image_fresh: "\<lbrakk>a \<sharp> atom ` (fn :: ('a :: at_base set)); b \<sharp> atom ` fn\<rbrakk> \<Longrightarrow> (a \<rightleftharpoons> b) \<bullet> fn = fn"
+  apply (simp add: fresh_def)
+  apply (simp add: supp_atom_image)
+  apply (fold fresh_def)
+  apply (simp add: swap_fresh_fresh)
+  done
 
 
 end

--- a/Nominal/Fv.thy	Thu Mar 11 19:43:50 2010 +0100
+++ b/Nominal/Fv.thy	Thu Mar 11 20:49:31 2010 +0100
@@ -714,7 +714,7 @@
   simp_tac (HOL_ss addsimps @{thms supports_def not_in_union} @ perm) THEN_ALL_NEW (
     REPEAT o rtac allI THEN' REPEAT o rtac impI THEN' split_conjs THEN'
     asm_full_simp_tac (HOL_ss addsimps @{thms fresh_def[symmetric]
-      swap_fresh_fresh fresh_atom swap_at_base_simps(3)}))
+      swap_fresh_fresh fresh_atom swap_at_base_simps(3) swap_atom_image_fresh}))
 *}
 
 ML {*
@@ -766,7 +766,7 @@
 ML {*
 fun fs_tac induct supports = ind_tac induct THEN_ALL_NEW (
   rtac @{thm supports_finite} THEN' resolve_tac supports) THEN_ALL_NEW
-  asm_full_simp_tac (HOL_ss addsimps @{thms supp_atom finite_insert finite.emptyI finite_Un})
+  asm_full_simp_tac (HOL_ss addsimps @{thms supp_atom supp_atom_image finite_insert finite.emptyI finite_Un})
 *}
 
 ML {*

--- a/Nominal/Parser.thy	Thu Mar 11 19:43:50 2010 +0100
+++ b/Nominal/Parser.thy	Thu Mar 11 20:49:31 2010 +0100
@@ -413,11 +413,11 @@
     [Attrib.internal (fn _ => Nominal_ThmDecls.eqvt_add)]), q_eqvt) lthy19;
   val supports = map (prove_supports lthy20 q_perm) consts
   val _ = map tracing (map PolyML.makestring supports);
-  val fin_supp = HOLogic.conj_elims (prove_fs lthy20 q_induct supports q_tys);
+  val fin_supp = HOLogic.conj_elims (prove_fs lthy20 q_induct supports q_tys) handle _ => []
   val thy3 = Local_Theory.exit_global lthy20;
   val lthy21 = Theory_Target.instantiation (qty_full_names, [], @{sort fs}) thy3;
   fun tac _ = Class.intro_classes_tac [] THEN (ALLGOALS (resolve_tac fin_supp))
-  val lthy22 = Class.prove_instantiation_instance tac lthy21;
+  val lthy22 = Class.prove_instantiation_instance tac lthy21 handle _ => lthy20
 in
   ((raw_dt_names, raw_bn_funs, raw_bn_eqs, raw_binds), lthy22)
 end