∀ {𝕜 : Type u_1} [inst : NontriviallyNormedField 𝕜] {E : Type uE} [inst_1 : NormedAddCommGroup E]
  [inst_2 : NormedSpace 𝕜 E] {s : Set E} {n : WithTop ℕ∞} {𝕜' : Type u_4} [inst_3 : NormedField 𝕜']
  [inst_4 : NormedAlgebra 𝕜 𝕜'] {f : E → 𝕜'},
  ContDiffOn 𝕜 n f s → (∀ x ∈ s, f x ≠ 0) → ContDiffOn 𝕜 n (fun x => (f x)⁻¹) s