∀ {B : Type u_2} [inst : CategoryTheory.Bicategory B] {C : Type u_6} [inst_1 : CategoryTheory.Bicategory C]
  {F G : CategoryTheory.Pseudofunctor B C} {η θ ι : F ⟶ G}
  (Γ : CategoryTheory.Pseudofunctor.StrongTrans.Modification η θ)
  (Δ : CategoryTheory.Pseudofunctor.StrongTrans.Modification θ ι) {a b : B} (f : a ⟶ b),
  CategoryTheory.CategoryStruct.comp
      (CategoryTheory.Bicategory.whiskerLeft (F.map f) (CategoryTheory.CategoryStruct.comp (Γ.app b) (Δ.app b)))
      (ι.naturality f).hom =
    CategoryTheory.CategoryStruct.comp (η.naturality f).hom
      (CategoryTheory.Bicategory.whiskerRight (CategoryTheory.CategoryStruct.comp (Γ.app a) (Δ.app a)) (G.map f))