proposition: Corollary toNat_fromNat0 n : @toNat n #0 = 0.
proof: Proof. by rewrite fromNat0 toNat_zero. Qed.
imports: Coq(ZArith.ZArith) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq fintype tuple div zmodp ssralg) ssrextra.nat ssrextra.tuple spec.spec