proposition: Lemma conv_conv_lift : forall (a b : term) n k, conv a b -> conv (lift_rec n a k) (lift_rec n b k).
proof: Proof. intros. elim H; intros; auto with coc core arith sets. apply trans_conv_red with (lift_rec n P k); auto with coc core arith sets. apply trans_conv_exp with (lift_rec n P k); auto with coc core arith sets. Qed.
imports: Arith Compare_dec Relations