(typed_true tint (Val.of_bool x) -> P).
Proof.
intuition.
apply H, typed_true_of_bool; auto.
Qed.

Ltac intro_if_new :=
 repeat match goal with
  | |- ?A -> _ => ((assert A by auto; fail 1) || fail 1) || intros _
  | |- (_ <-> _) -> _ =>
         intro
  | |- (?A /\ ?B) -> ?C =>
         apply (@and_ind A B C)
  | |- isptr (force_ptr ?P) -> ?Q =>
         apply (isptr_force_ptr'' P Q)
  | |- isptr (offset_val ?i ?P) -> ?Q =>
         apply (isptr_offset_val'' i P Q)
  | H: is_pointer_or_null ?P |- isptr ?P -> _ =>
         clear H
  | |- ?x = ?y -> _ =>
          let H := fresh in intro H;
                     first [subst x | subst y
                             | is_var x; rewrite H
                             | is_var y; rewrite <- H
                             | solve [discriminate H]
                             | idtac]
  | |- isptr ?x -> _ =>
          let H := fresh "P" x in intro H
  | |- is_pointer_or_null ?x =>
          let H := fresh "PN" x in intro H
  | |- typed_false _ (Val.of_bool _) -> _ =>
          simple apply typed_false_of_bool'
  | |- typed_true _ (Val.of_bool _) -> _ =>
          simple apply typed_true_of_bool'
  | |-e apply conj; auto);
     fail 3
     end
end || auto with nocore saturate_local)
 || simple apply prop_True_right.


Ltac saturate_local :=
simple eapply saturate_aux21x;
 [repeat simple apply saturate_aux20;
   (* use already_saturated if want to be fancy,
         otherwise the next lines *)
    auto with nocore saturate_local;
    simple apply prop_True_right
(* | cbv beta; reflexivity    this line only for use with saturate_aux21 *)
 | simple apply derives_extract_prop;
   match goal with |- _ -> ?A =>Lemma prop_right_emp {A} {NA: NatDed A}:
 forall P: Prop, P -> emp |-- !! P.
Proof. intros. normalize.Qed.

Ltac prop_right_cautious :=
 try solve [simple apply prop_right; auto].

(**********************************************************)
(* testing
Parameter f: nat -> Prop.
Parameter g h : mpred.

Goal ( !! f 1 && ((h && !! f 2) && h ) && (!! f 3 && (g && (!!f 4 && !! f 5) && !! f 6)) |-- FF).

*)

(*****************************************************************)

(* Specifications: *)
Proof. intros. apply derives_trans with (!!Y); auto. apply prop_derives; auto.
intros. induction R; auto.