intros a b; case a; case b; simpl in |- *; auto.
intros d c A0' c0 nZA2 H'0; split; auto.
case H'0; intros H'1 H'2; clear H'0.
apply
(eqA_trans _ _ _ _ _ _ _ _ _ cs)
with (y := divA (invA (multA (divA d A0' nZA2) A0')) A0' nZA2);
auto.
apply
(eqA_trans _ _ _ _ _ _ _ _ _ cs)
with (y := divA (multA (invA (divA d A0' nZA2)) A0') A0' nZA2);
auto.
apply divA_eqA_comp with (1 := cs); auto.
apply (eqA_sym _ _ _ _ _ _ _ _ _ cs); apply multA_invA_com_l with (1 := cs);
auto.
apply
(eqA_trans _ _ _ _ _ _ _ _ _ cs)
with (y := multA (invA (divA d A0' nZA2)) (divA A0' A0' nZA2));
auto.
apply divA_multA_comp_l with (1 := cs).
apply
(eqA_trans _ _ _ _ _ _ _ _ _ cs)
with (y := multA (invA (divA d A0' nZA2)) A1); auto.
apply multA_eqA_comp with (1 := cs); auto.
apply divA_A1 with (1 := cs).
apply multA_A1_r with (1 := cs).
Qed.

Theorem divTerm_invTerm_r :
forall (a b : Term A n) (nZa : ~ zeroP (A:=A) A0 eqA (n:=n) a)
(nZia : ~ zeroP (A:=A) A0 eqA (n:=n) (invTerm (A:=A) invA (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 b nZia)
(invTerm (A:=A) invA (n:=n) (divTerm b nZa)).