(* Does not hold, since readonlyLD refers to Cur permissions
Lemma external_call_readonlyLD:
  forall (ef : external_function) (F V : Type) (ge : Genv.t F V)
    (vargs : list val) (m1 : mem) (t : trace) (vres : val) (m2 : mem),
    external_call ef ge vargs m1 t vres m2 ->
  forall b, Mem.valid_block m1 b -> readonlyLD m1 b m2.
Proof. intros.
  eapply readonly_readonlyLD.
  eapply ec_readonly_strong; eassumption.
Qed.
*)
Definition val_has_type_opt' (v: option val) (ty: typ) :=
 match v with
 | None => True
 | Some v' => Val.has_type v' ty
 end.Definition val_has_type_opt (v: option val) (sig: signature) :=
  val_has_type_opt' v (proj_sig_res sig).Definition is_vundef (v : val) : bool :=
  match v with
    | Vundef => true
    | _ => false
  end.Definition vals_def (vs : list val) :=
  List.forallb (fun v => negb (is_vundef v)) vs.Definition genv2blocksBool {F V : Type} (ge : Genv.t F V):=
  (fun b =>
      match Genv.invert_symbol ge b with
        Some id => true
      | None => false
      end,
   fun b => match Genv.find_var_info ge b with
                  Some gv => true
                | None => false
            end).Definition isGlobalBlock {F V : Type} (ge : Genv.t F V) :=
  fun b => (fst (genv2blocksBool ge)) b || (snd (genv2blocksBool ge)) b.

Lemma find_symbol_isGlobal: forall {V F} (ge : Genv.t F V) x b (Find: Genv.find_symbol ge x = Some b), isGlobalBlock ge b = true.