∀ {B : Type u₁} [inst : CategoryTheory.Bicategory B] {C : Type u₂} [inst_1 : CategoryTheory.Bicategory C]
  {F G : CategoryTheory.OplaxFunctor B C} (self : CategoryTheory.Oplax.LaxTrans F G) {a b : B} {f g : a ⟶ b}
  (η : f ⟶ g),
  CategoryTheory.CategoryStruct.comp (self.naturality f)
      (CategoryTheory.Bicategory.whiskerRight (F.map₂ η) (self.app b)) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.Bicategory.whiskerLeft (self.app a) (G.map₂ η))
      (self.naturality g)