∀ {E : Type u_1} {ι : Type u_2} [inst : NormedAddCommGroup E] [inst_1 : NormedSpace ℂ E] {U : Set ℂ} {φ : Filter ι}
  {F : ι → ℂ → E} {f : ℂ → E} [CompleteSpace E] [φ.NeBot],
  TendstoLocallyUniformlyOn F f φ U → (∀ᶠ (n : ι) in φ, DifferentiableOn ℂ (F n) U) → IsOpen U → DifferentiableOn ℂ f U