intros a b Q H'; elim H'; auto.
intros x y H'0 H'1 H'2.
apply CombLinear_comp with (p := x); auto.
apply eqp_imp_canonical with (p := x) (1 := cs); auto.
intros x y z H'0 H'1 H'2 H'3 H'4.
apply H'2; auto.
apply canonical_reduce with (1 := cs) (3 := H'0) (p := x); auto.
apply reduce_cb with (a := x); auto.
Qed.

Theorem reducestar_cb :
forall (a b : list (Term A n)) (Q : list (poly A0 eqA ltM)),
reducestar A A0 A1 eqA invA minusA multA divA eqA_dec n ltM ltM_dec Q a b ->
canonical A0 eqA ltM a -> CombLinear Q a -> CombLinear Q b.