proposition: Lemma nattorig_plus : ∏ {X : rig} (n m : nat), (nattorig (n + m) : X) = (nattorig n + nattorig m)%rig.
proof: Proof. intros X n m. apply (natmult_plus (X := rigaddabmonoid X)). 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