intros Q p H.
generalize (Reducef Q (mks p H)).
intros H'; elim H'.
simpl in |- *.
intros x H'0; exists (s2p A A0 eqA n ltM x); try assumption.
Qed.

Theorem reducestar_trans :
forall (Q : list (poly A0 eqA ltM)) (x y z : list (Term A n)),
canonical A0 eqA ltM x ->
reduceplus A A0 A1 eqA invA minusA multA divA eqA_dec n ltM ltM_dec Q x y ->
reducestar Q y z -> reducestar Q x z.