intros m l; elim l; simpl in |- *; auto.
intros a l0 H' H'0 H'1.
apply mults_order_l; auto.
Qed.

Lemma canonical_mults_inv :
forall (p : list (Term A n)) (a : Term A n),
~ zeroP (A:=A) A0 eqA (n:=n) a ->
canonical A0 eqA ltM (mults a p) -> canonical A0 eqA ltM p.