proposition: Lemma nat_num1 : 1 \is a nat_num.
proof: Proof. exact: (natr_nat 1). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)