{T : Type u₁} →
  [inst : CategoryTheory.Category.{v₁, u₁} T] →
    {D : Type u₂} →
      [inst_1 : CategoryTheory.Category.{v₂, u₂} D] →
        {C : Type u₃} →
          [inst_2 : CategoryTheory.Category.{v₃, u₃} C] →
            (F : CategoryTheory.Functor C T) →
              (G : CategoryTheory.Functor D T) →
                (c : C) →
                  CategoryTheory.Functor (CategoryTheory.StructuredArrow c (CategoryTheory.Comma.fst F G))
                    (CategoryTheory.Comma ((CategoryTheory.Under.forget c).comp F) G)