intros p L; case p; unfold nf in |- *; auto.
unfold nf in |- *; auto.
intros x c;
case
(Reducef A A0 A1 eqA plusA invA minusA multA divA cs eqA_dec n ltM ltM_dec
os L (exist (fun l : list (Term A n) => canonical A0 eqA ltM l) x c)).
unfold LetP in |- *.
simpl in |- *; intros x0; case x0; simpl in |- *; auto.
intros x1 c0 H' H'0 H'1.
lapply
(reducestar_divp (mks A A0 eqA n ltM x c) (mks A A0 eqA n ltM x1 c0) L);
simpl in |- *;
[ intros H'5; lapply H'5; [ intros H'6; clear H'5 | clear H'5 ] | idtac ];
auto.
case H'6; intros r E; case E; intros H'2 H'3; case H'3; intros H'4 H'5;
clear H'3 E H'6.
case H'2; [ intros H'3; clear H'2 | intros H'3; clear H'2 ].
case H'5; rewrite <- H'3.
generalize c0 H'1; case x1; auto.
exists r; split; [ idtac | split ]; auto.
Qed.

Theorem zerop_elim_cb :
forall (L : list (poly A0 eqA ltM)) (p q : poly A0 eqA ltM),
zerop A A0 eqA n ltM p ->
Cb A A0 eqA plusA multA eqA_dec n ltM ltM_dec q (p :: L) ->
Cb A A0 eqA plusA multA eqA_dec n ltM ltM_dec q L.