Proof (SRth_ARth Nsth Nth).

(* Specifications: *)
Lemma Neqb_ok : forall x y, N.eqb x y = true -> x = y.
Lemma gen_phiN_add : forall x y, [x + y] == [x] + [y].
Lemma gen_phiN_mult : forall x y, [x * y] == [x] * [y].
Lemma gen_phiN_sub : forall x y, [Nsub x y] == [x] - [y].
End NMORPHISM.