intros a b H'.
apply (eqT_trans A n) with (y := b); auto.
Qed.

Lemma invTerm_T1_eqT_comp :
forall a b : Term A n,
eqT a b ->
eqT a
(invTerm (A:=A) invA (n:=n) (multTerm (A:=A) multA (n:=n) (T1 A1 n) b)).