proposition: Fact Z_of_int_is_additive : additive Z_of_int.
proof: Proof. by move=> m n; rewrite !Z_of_intE raddfB. 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)