{ obj := fun R => MonCat.of ↑R, map := fun {X Y} f => MonCat.ofHom ↑(SemiRingCat.Hom.hom f),
        map_id := SemiRingCat.hasForgetToMonCat._proof_1, map_comp := @SemiRingCat.hasForgetToMonCat._proof_2 }.comp
    (CategoryTheory.forget MonCat) =
  CategoryTheory.forget SemiRingCat