intros a b H' p; elim p; simpl in |- *; auto.
intros H'0 c H'1; elim H'1.
intros a0 l H'0 H'1 c H'2; elim H'2;
[ intros H'3; rewrite <- H'3; clear H'2 | intros H'3; clear H'2 ];
auto.
2: apply H'0; auto.
2: apply canonical_skip_fst with (b := a0); auto.
split; auto.
apply multTerm_ltT_l; auto.
apply (canonical_pX_order A A0 eqA) with (l := l); auto.
apply (eqT_trans A n) with (y := multTerm (A:=A) multA (n:=n) a0 b); auto.
apply (eqTerm_imp_eqT A eqA); auto.
apply multTerm_eqT; auto.
apply (eqTerm_imp_eqT A eqA); auto.
apply
(eqTerm_trans _ _ _ _ _ _ _ _ _ cs n)
with
(y := multTerm (A:=A) multA (n:=n)
(divTerm (A:=A) (A0:=A0) (eqA:=eqA) divA (n:=n) b (b:=b) H') a0);
auto.
apply (eqTerm_sym _ _ _ _ _ _ _ _ _ cs n); auto.
Qed.

Theorem in_minuspf_spoly_in :
forall a b : Term A n,
eqT (ppc (A:=A) A1 (n:=n) a b) (multTerm (A:=A) multA (n:=n) a b) ->
forall p q : list (Term A n),
canonical A0 eqA ltM (pX a p) ->
canonical A0 eqA ltM (pX b q) ->
forall c : Term A n,
In c (mults (A:=A) multA (n:=n) b p) ->
In c
(minuspf A A0 A1 eqA invA minusA multA eqA_dec n ltM ltM_dec
(mults (A:=A) multA (n:=n) b p) (mults (A:=A) multA (n:=n) a q)).