proposition: Theorem canonical_reduceplus : forall (Q : list (poly A0 eqA ltM)) (p q : list (Term A n)), reduceplus Q p q -> canonical A0 eqA ltM p -> canonical A0 eqA ltM q.
proof: Proof. Proof using plusA os cs. intros Q p q H'; elim H'; auto. intros x y H H0. apply eqp_imp_canonical with (1 := cs) (p := x); auto. intros x y z H'0 H'1 H'2 H'3. apply H'2; auto. apply canonical_reduce with (1 := cs) (3 := H'0); auto. Qed.