proposition: Lemma Z_of_N_morphism@{} : IsSemiRingPreserving (cast N Z).
proof: Proof. repeat (constructor; try apply _). - intros x y. apply Z_path. red. simpl. ring_with_nat. - intros x y. apply Z_path. red;simpl. ring_with_nat. Qed.
imports: HoTT.HIT.quotient HoTT.TruncType HoTT.Basics.Trunc HoTT.Classes.implementations.peano_naturals HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.interfaces.orders HoTT.Classes.interfaces.integers HoTT.Classes.theory.rings HoTT.Classes.theory.groups HoTT.Classes.theory.apartness HoTT.Classes.orders.sum HoTT.Classes.orders.rings HoTT.Classes.tactics.ring_tac HoTT.Classes.theory.naturals