Sort u_1 →
  {C : Type u} →
    [inst : CategoryTheory.Category.{v, u} C] →
      {F : CategoryTheory.Functor C CategoryTheory.Cat} →
        {X Y : CategoryTheory.Grothendieck F} →
          X.Hom Y →
            {C' : Type u} →
              [inst' : CategoryTheory.Category.{v, u} C'] →
                {F' : CategoryTheory.Functor C' CategoryTheory.Cat} →
                  {X' Y' : CategoryTheory.Grothendieck F'} → X'.Hom Y' → Sort u_1