{A : Type u₁} →
  [inst : CategoryTheory.Category.{v₁, u₁} A] →
    {B : Type u₂} →
      [inst_1 : CategoryTheory.Category.{v₂, u₂} B] →
        {T : Type u₃} →
          [inst_2 : CategoryTheory.Category.{v₃, u₃} T] →
            {L : CategoryTheory.Functor A T} →
              {R : CategoryTheory.Functor B T} →
                [inst_3 : Inhabited (CategoryTheory.Comma L R)] →
                  Inhabited (CategoryTheory.CommaMorphism default default)