l3lab/ntp-mathlib huggingface dataset:
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    

Proof state:
case succ
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
⊢ (iteratedFDeriv 𝕜 (Nat.succ k) fun y => ∑' (n : α), f n y) = fun x =>
    ∑' (n : α), iteratedFDeriv 𝕜 (Nat.succ k) (f n) x

Next tactic:
have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
    

Proof state:
case succ
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0
⊢ (iteratedFDeriv 𝕜 (Nat.succ k) fun y => ∑' (n : α), f n y) = fun x =>
    ∑' (n : α), iteratedFDeriv 𝕜 (Nat.succ k) (f n) x

Next tactic:
simp_rw [iteratedFDeriv_succ_eq_comp_left, IH h'k.le]
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
    simp_rw [iteratedFDeriv_succ_eq_comp_left, IH h'k.le]
    

Proof state:
case succ
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0
⊢ (⇑(continuousMultilinearCurryLeftEquiv 𝕜 (fun x => E) F) ∘ fderiv 𝕜 fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x) =
    fun x =>
    ∑' (n : α), (⇑(continuousMultilinearCurryLeftEquiv 𝕜 (fun x => E) F) ∘ fderiv 𝕜 (iteratedFDeriv 𝕜 k (f n))) x

Next tactic:
rw [fderiv_tsum (hv _ hk) (fun n => (hf n).differentiable_iteratedFDeriv h'k) _ A]
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
    simp_rw [iteratedFDeriv_succ_eq_comp_left, IH h'k.le]
    rw [fderiv_tsum (hv _ hk) (fun n => (hf n).differentiable_iteratedFDeriv h'k) _ A]
    · 

Proof state:
case succ
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0
⊢ (⇑(continuousMultilinearCurryLeftEquiv 𝕜 (fun x => E) F) ∘ fun x =>
      ∑' (n : α), fderiv 𝕜 (fun x => iteratedFDeriv 𝕜 k (f n) x) x) =
    fun x =>
    ∑' (n : α), (⇑(continuousMultilinearCurryLeftEquiv 𝕜 (fun x => E) F) ∘ fderiv 𝕜 (iteratedFDeriv 𝕜 k (f n))) x

Next tactic:
ext1 x
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
    simp_rw [iteratedFDeriv_succ_eq_comp_left, IH h'k.le]
    rw [fderiv_tsum (hv _ hk) (fun n => (hf n).differentiable_iteratedFDeriv h'k) _ A]
    · ext1 x
      

Proof state:
case succ.h
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x✝ : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0
x : E
⊢ (⇑(continuousMultilinearCurryLeftEquiv 𝕜 (fun x => E) F) ∘ fun x =>
        ∑' (n : α), fderiv 𝕜 (fun x => iteratedFDeriv 𝕜 k (f n) x) x)
      x =
    ∑' (n : α), (⇑(continuousMultilinearCurryLeftEquiv 𝕜 (fun x => E) F) ∘ fderiv 𝕜 (iteratedFDeriv 𝕜 k (f n))) x

Next tactic:
exact (continuousMultilinearCurryLeftEquiv 𝕜
        (fun _ : Fin (k + 1) => E) F).toContinuousLinearEquiv.map_tsum
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
    simp_rw [iteratedFDeriv_succ_eq_comp_left, IH h'k.le]
    rw [fderiv_tsum (hv _ hk) (fun n => (hf n).differentiable_iteratedFDeriv h'k) _ A]
    · ext1 x
      exact (continuousMultilinearCurryLeftEquiv 𝕜
        (fun _ : Fin (k + 1) => E) F).toContinuousLinearEquiv.map_tsum
    · 

Proof state:
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0
⊢ ∀ (n : α) (x : E), ‖fderiv 𝕜 (fun x => iteratedFDeriv 𝕜 k (f n) x) x‖ ≤ v (Nat.succ k) n

Next tactic:
intro n x
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) :
    (iteratedFDeriv 𝕜 k fun y => ∑' n, f n y) = fun x => ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  induction' k with k IH
  · ext1 x
    simp_rw [iteratedFDeriv_zero_eq_comp]
    exact (continuousMultilinearCurryFin0 𝕜 E F).symm.toContinuousLinearEquiv.map_tsum
  · have h'k : (k : ℕ∞) < N := lt_of_lt_of_le (WithTop.coe_lt_coe.2 (Nat.lt_succ_self _)) hk
    have A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0 :=
      .of_norm_bounded (v k) (hv k h'k.le) fun n => h'f k n 0 h'k.le
    simp_rw [iteratedFDeriv_succ_eq_comp_left, IH h'k.le]
    rw [fderiv_tsum (hv _ hk) (fun n => (hf n).differentiable_iteratedFDeriv h'k) _ A]
    · ext1 x
      exact (continuousMultilinearCurryLeftEquiv 𝕜
        (fun _ : Fin (k + 1) => E) F).toContinuousLinearEquiv.map_tsum
    · intro n x
      

Proof state:
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x✝ : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
IH : ↑k ≤ N → (iteratedFDeriv 𝕜 k fun y => ∑' (n : α), f n y) = fun x => ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x
hk : ↑(Nat.succ k) ≤ N
h'k : ↑k < N
A : Summable fun n => iteratedFDeriv 𝕜 k (f n) 0
n : α
x : E
⊢ ‖fderiv 𝕜 (fun x => iteratedFDeriv 𝕜 k (f n) x) x‖ ≤ v (Nat.succ k) n

Next tactic:
simpa only [iteratedFDeriv_succ_eq_comp_left, LinearIsometryEquiv.norm_map, comp_apply]
        using h'f k.succ n x hk
/-- Consider a series of smooth functions, with summable uniform bounds on the successive
derivatives. Then the iterated derivative of the sum is the sum of the iterated derivative. -/
theorem iteratedFDeriv_tsum_apply (hf : ∀ i, ContDiff 𝕜 N (f i))
    (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) {k : ℕ}
    (hk : (k : ℕ∞) ≤ N) (x : E) :
    iteratedFDeriv 𝕜 k (fun y => ∑' n, f n y) x = ∑' n, iteratedFDeriv 𝕜 k (f n) x := by
  

Proof state:
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x✝ : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
k : ℕ
hk : ↑k ≤ N
x : E
⊢ iteratedFDeriv 𝕜 k (fun y => ∑' (n : α), f n y) x = ∑' (n : α), iteratedFDeriv 𝕜 k (f n) x

Next tactic:
rw [iteratedFDeriv_tsum hf hv h'f hk]
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  

Proof state:
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
⊢ ContDiff 𝕜 N fun x => ∑' (i : α), f i x

Next tactic:
rw [contDiff_iff_continuous_differentiable]
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  rw [contDiff_iff_continuous_differentiable]
  

Proof state:
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
⊢ (∀ (m : ℕ), ↑m ≤ N → Continuous fun x => iteratedFDeriv 𝕜 m (fun x => ∑' (i : α), f i x) x) ∧
    ∀ (m : ℕ), ↑m < N → Differentiable 𝕜 fun x => iteratedFDeriv 𝕜 m (fun x => ∑' (i : α), f i x) x

Next tactic:
constructor
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  rw [contDiff_iff_continuous_differentiable]
  constructor
  · 

Proof state:
case left
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
⊢ ∀ (m : ℕ), ↑m ≤ N → Continuous fun x => iteratedFDeriv 𝕜 m (fun x => ∑' (i : α), f i x) x

Next tactic:
intro m hm
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  rw [contDiff_iff_continuous_differentiable]
  constructor
  · intro m hm
    

Proof state:
case left
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
m : ℕ
hm : ↑m ≤ N
⊢ Continuous fun x => iteratedFDeriv 𝕜 m (fun x => ∑' (i : α), f i x) x

Next tactic:
rw [iteratedFDeriv_tsum hf hv h'f hm]
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  rw [contDiff_iff_continuous_differentiable]
  constructor
  · intro m hm
    rw [iteratedFDeriv_tsum hf hv h'f hm]
    

Proof state:
case left
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
m : ℕ
hm : ↑m ≤ N
⊢ Continuous fun x => (fun x => ∑' (n : α), iteratedFDeriv 𝕜 m (f n) x) x

Next tactic:
refine' continuous_tsum _ (hv m hm) _
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  rw [contDiff_iff_continuous_differentiable]
  constructor
  · intro m hm
    rw [iteratedFDeriv_tsum hf hv h'f hm]
    refine' continuous_tsum _ (hv m hm) _
    · 

Proof state:
case left.refine'_1
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
m : ℕ
hm : ↑m ≤ N
⊢ ∀ (i : α), Continuous fun x => iteratedFDeriv 𝕜 m (f i) x

Next tactic:
intro i
/-- Consider a series of functions `∑' i, f i x`. Assume that each individual function `f i` is of
class `C^N`, and moreover there is a uniform summable upper bound on the `k`-th derivative
for each `k ≤ N`. Then the series is also `C^N`. -/
theorem contDiff_tsum (hf : ∀ i, ContDiff 𝕜 N (f i)) (hv : ∀ k : ℕ, (k : ℕ∞) ≤ N → Summable (v k))
    (h'f : ∀ (k : ℕ) (i : α) (x : E), (k : ℕ∞) ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i) :
    ContDiff 𝕜 N fun x => ∑' i, f i x := by
  rw [contDiff_iff_continuous_differentiable]
  constructor
  · intro m hm
    rw [iteratedFDeriv_tsum hf hv h'f hm]
    refine' continuous_tsum _ (hv m hm) _
    · intro i
      

Proof state:
case left.refine'_1
α : Type u_1
β : Type u_2
𝕜 : Type u_3
E : Type u_4
F : Type u_5
inst✝⁵ : IsROrC 𝕜
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
inst✝² : NormedAddCommGroup F
inst✝¹ : CompleteSpace F
u : α → ℝ
inst✝ : NormedSpace 𝕜 F
f : α → E → F
f' : α → E → E →L[𝕜] F
v : ℕ → α → ℝ
s : Set E
x₀ x : E
N : ℕ∞
hf : ∀ (i : α), ContDiff 𝕜 N (f i)
hv : ∀ (k : ℕ), ↑k ≤ N → Summable (v k)
h'f : ∀ (k : ℕ) (i : α) (x : E), ↑k ≤ N → ‖iteratedFDeriv 𝕜 k (f i) x‖ ≤ v k i
m : ℕ
hm : ↑m ≤ N
i : α
⊢ Continuous fun x => iteratedFDeriv 𝕜 m (f i) x

Next tactic:
exact ContDiff.continuous_iteratedFDeriv hm (hf i)