proposition: Lemma S_gt_0 : forall a, 0 < S a.
proof: Proof. intros;apply le_S_S,zero_least. Qed.
imports: HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.interfaces.naturals HoTT.Classes.interfaces.orders HoTT.Classes.theory.rings HoTT.Classes.orders.semirings HoTT.Classes.theory.apartness