intros Q x y z H' H'0 H'1; inversion H'1.
apply reducestar0; auto.
apply reduceplus_trans with (1 := cs) (y := y); auto.
Qed.

Theorem reducestar_reduceplus :
forall (Q : list (poly A0 eqA ltM)) (p q : list (Term A n)),
reducestar Q p q ->
reduceplus A A0 A1 eqA invA minusA multA divA eqA_dec n ltM ltM_dec Q p q.