English
Simplified one-variable variant: if f is C^n, then iteratedFDeriv_right holds.
Русский
Упрощённый одномерный вариант: если f ∈ C^n, то итеративная производная существует и гладка.
LaTeX
$$$\operatorname{ContDiffAt}_{\mathbb{K}} n f x_0 \Rightarrow \operatorname{ContDiffAt}_{\mathbb{K}} m (\text{iteratedFDeriv } i f) x_0$$$
Lean4
theorem iteratedFDeriv_right {i : ℕ} (hf : ContDiffAt 𝕜 n f x₀) (hmn : m + i ≤ n) :
ContDiffAt 𝕜 m (iteratedFDeriv 𝕜 i f) x₀ :=
by
rw [← iteratedFDerivWithin_univ, ← contDiffWithinAt_univ] at *
exact hf.iteratedFDerivWithin_right uniqueDiffOn_univ hmn trivial