proposition: Fact N_of_nat_is_semi_additive : semi_additive N.of_nat.
proof: Proof. by split=> //= m n; rewrite /GRing.add /=; lia. Qed.
imports: Coq(ZArith) HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop finset prime) mathcomp(order binomial ssralg countalg ssrnum ssrint) mathcomp(zify_ssreflect)