{B : Type u₁} →
  [inst : CategoryTheory.Bicategory B] →
    {C : Type u₂} →
      [inst_1 : CategoryTheory.Bicategory C] →
        {F G : CategoryTheory.OplaxFunctor B C} →
          (η : CategoryTheory.Oplax.OplaxTrans F G) →
            [∀ (a b : B) (f : a ⟶ b), CategoryTheory.IsIso (η.naturality f)] → CategoryTheory.Oplax.StrongTrans F G