intros a b H' H'0; red in |- *; intros H'1.
apply H'.
apply zeroP_comp_eqTerm with (a := b); auto.
apply eqTerm_sym; auto.
Qed.
Set Implicit Arguments.
Unset Strict Implicit.
Definition plusTerm : Term -> Term -> Term.
intros x; case x; intros b2 c2; intros y; case y; intros b3 c3;
exact (plusA b2 b3, c2).
Defined.
Set Strict Implicit.
Unset Implicit Arguments.

Theorem zeroP_plusTermr :
forall a b : Term, eqT a b -> zeroP b -> eqTerm a (plusTerm a b).