∀ {B : Type u₁} [inst : CategoryTheory.Bicategory B] {C : Type u₂} [inst_1 : CategoryTheory.Bicategory C]
  {F G : CategoryTheory.OplaxFunctor B C} {η θ : F ⟶ G}
  (Γ : (CategoryTheory.Oplax.StrongTrans.toOplax η).Modification (CategoryTheory.Oplax.StrongTrans.toOplax θ)) (a : B),
  (CategoryTheory.Oplax.StrongTrans.Modification.mkOfOplax Γ).app a = Γ.app a