proposition: Lemma nattorig_mult : ∏ {X : rig} (n m : nat), (nattorig (n * m) : X) = (nattorig n * nattorig m)%rig.
proof: Proof. intros X n m. unfold nattorig. rewrite (natmult_mult (X := rigaddabmonoid X)), <- nattorig_natmult. reflexivity. Qed.
imports: UniMath.Foundations.NaturalNumbers UniMath.Algebra.RigsAndRings UniMath.Algebra.Groups UniMath.Algebra.DivisionRig UniMath.Algebra.Domains_and_Fields UniMath.Algebra.ConstructiveStructures UniMath.MoreFoundations.Tactics