∀ {𝕜 : Type u} [inst : NontriviallyNormedField 𝕜] {F : Type v} [inst_1 : NormedAddCommGroup F]
  [inst_2 : NormedSpace 𝕜 F] (f : 𝕜 → F) {t : Set 𝕜},
  Dense t → Set.range (deriv f) ⊆ closure ↑(Submodule.span 𝕜 (f '' t))