proposition: Lemma acc_A_B_lexprod : forall x:A, Acc leA x -> (well_founded leB) -> forall y:B, Acc leB y -> Acc lexprod (x, y).
proof: Proof. induction 1 as [x _ IHAcc]; intros H2 y. induction 1 as [x0 H IHAcc0]. apply Acc_intro. destruct y as [x2 y1]; intro Hlex. depelim Hlex. apply IHAcc; auto with relations. now apply IHAcc0. Defined.
imports: Equations.Type.Loader Equations.Type.Relation Equations.Type.WellFounded