intros p;
apply
(eqp_trans _ _ _ _ _ _ _ _ _ cs n)
with
(y := pluspf (A:=A) A0 (eqA:=eqA) plusA eqA_dec (n:=n) (ltM:=ltM)
ltM_dec (pO A n)
(mults (A:=A) multA (n:=n)
(invTerm (A:=A) invA (n:=n) (T1 A1 n)) p));
auto; simpl in |- *; auto.
Qed.
Hint Resolve minuspf_pOmults.

Theorem mults_pO :
forall (p : list (Term A n)) (a b : Term A n),
eqT a b ->
zeroP (A:=A) A0 eqA (n:=n) (minusTerm (A:=A) minusA (n:=n) a b) ->
eqP A eqA n (pO A n)
(minuspf (mults (A:=A) multA (n:=n) a p) (mults (A:=A) multA (n:=n) b p)).