intros a b; case a; case b; simpl in |- *; auto.
intros a1 m1 a2 m2 H1 H2; split; auto.
apply (eqA_trans _ _ _ _ _ _ _ _ _ cs) with (y := plusA a2 A0); auto.
apply (eqA_sym _ _ _ _ _ _ _ _ _ cs); auto.
Qed.

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