exists [];reflexivity.
destruct a;try (apply plus_is_O in H as (?&_);simpl in H;discriminate);
unfold sizel in H;simpl in H;
destruct (IHΓ H);[exists (AVar p::x)|exists (ABot::x)];simpl;f_equal;assumption.
Qed.
Ltac temp4 := try contradiction;do 2 econstructor;repeat ((left;in_solve;fail)||right);in_solve.

(* Specifications: *)
Lemma bool_false : forall b, b=false -> ~Is_true b.
intros;subst;auto.