intros a b c d; case a; case b; case c; case d; simpl in |- *; auto.
intros A0' c0 d2 c2 d3 c3 d4 c4 nZd2 H'0 H'1 H'2.
case H'2; intros H'3 H'4; clear H'2.
case H'1; intros H'2 H'5; clear H'1.
split; auto.
rewrite H'5; rewrite H'4; auto.
Qed.
Hint Resolve eqTerm_divTerm_comp.

Theorem divTerm_multTerm_l :
forall (a b c : Term A n) (nZa : ~ zeroP (A:=A) A0 eqA (n:=n) a),
eqTerm (A:=A) eqA (n:=n) b (multTerm (A:=A) multA (n:=n) (divTerm b nZa) a) ->
eqTerm (A:=A) eqA (n:=n) (divTerm (multTerm (A:=A) multA (n:=n) c b) nZa)
(multTerm (A:=A) multA (n:=n) c (divTerm b nZa)).