intros p; elim p; simpl in |- *; auto.
intros; apply (eqp_sym _ _ _ _ _ _ _ _ _ cs n);
apply p0_pluspf_l with (1 := cs); auto.
intros a l H' a0 b H'0 H'1 H'2 H'3 H'4.
cut (canonical A0 eqA ltM l); try apply canonical_imp_canonical with (a := a);
auto; intros C0.
apply
(eqp_trans _ _ _ _ _ _ _ _ _ cs n)
with
(y := pX
(plusTerm (A:=A) plusA (n:=n) (multTerm (A:=A) multA (n:=n) a0 a)
(multTerm (A:=A) multA (n:=n) b a))
(pluspf (A:=A) A0 (eqA:=eqA) plusA eqA_dec (n:=n) (ltM:=ltM)
ltM_dec (mults a0 l) (mults b l)));
auto.
apply
(eqp_trans _ _ _ _ _ _ _ _ _ cs n)
with
(y := pX
(plusTerm (A:=A) plusA (n:=n) (multTerm (A:=A) multA (n:=n) a0 a)
(multTerm (A:=A) multA (n:=n) b a))
(pluspf (A:=A) A0 (eqA:=eqA) plusA eqA_dec (n:=n) (ltM:=ltM)
ltM_dec (mults a0 l) (mults b l)));
auto.
apply (eqpP1 _ eqA n); auto.
apply (eqTerm_sym _ _ _ _ _ _ _ _ _ cs n);
apply multTerm_plusTerm_dist_l with (1 := cs); auto.
apply pluspf_inv3b with (1 := cs); auto.
red in |- *; intros H'5;
absurd
(zeroP (A:=A) A0 eqA (n:=n)
(multTerm (A:=A) multA (n:=n) (plusTerm (A:=A) plusA (n:=n) a0 b) a));
auto.
red in |- *; intros H'6.
elim
multTerm_zeroP_div
with (1 := cs) (a := plusTerm (A:=A) plusA (n:=n) a0 b) (b := a);
auto.
intros H'7; absurd (zeroP (A:=A) A0 eqA (n:=n) a); auto.
apply canonical_nzeroP with (ltM := ltM) (p := l); auto.
apply
zeroP_comp_eqTerm
with
(1 := cs)
(a := plusTerm (A:=A) plusA (n:=n) (multTerm (A:=A) multA (n:=n) a0 a)
(multTerm (A:=A) multA (n:=n) b a)); auto.
apply multTerm_plusTerm_dist_l with (1 := cs); auto.
Qed.

Theorem mults_dist2 :
forall (p : list (Term A n)) (a b : Term A n),
eqT a b ->
~ zeroP (A:=A) A0 eqA (n:=n) a ->
~ zeroP (A:=A) A0 eqA (n:=n) b ->
zeroP (A:=A) A0 eqA (n:=n) (plusTerm (A:=A) plusA (n:=n) a b) ->
canonical A0 eqA ltM p ->
eqP A eqA n (pO A n)
(pluspf (A:=A) A0 (eqA:=eqA) plusA eqA_dec (n:=n) (ltM:=ltM) ltM_dec
(mults a p) (mults b p)).