Theorem: LocallyBoundedVariationOn.ae_differentiableWithinAt_of_mem_pi
File: Mathlib/Analysis/BoundedVariation.lean

Proof steps:
state_before: α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
⊢ ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ f s x
state_after: α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
A : ∀ (i : ι), LipschitzWith 1 fun x => x i
⊢ ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ f s x
tactic: have A : ∀ i : ι, LipschitzWith 1 fun x : ι → ℝ => x i := fun i => LipschitzWith.eval i
state_before: α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
A : ∀ (i : ι), LipschitzWith 1 fun x => x i
⊢ ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ f s x
state_after: α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
A : ∀ (i : ι), LipschitzWith 1 fun x => x i
this : ∀ (i : ι), ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ (fun x => f x i) s x
⊢ ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ f s x
tactic: have : ∀ i : ι, ∀ᵐ x, x ∈ s → DifferentiableWithinAt ℝ (fun x : ℝ => f x i) s x := fun i ↦ by
    apply ae_differentiableWithinAt_of_mem_real
    exact LipschitzWith.comp_locallyBoundedVariationOn (A i) h
state_before: α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
A : ∀ (i : ι), LipschitzWith 1 fun x => x i
this : ∀ (i : ι), ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ (fun x => f x i) s x
⊢ ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ f s x
state_after: case h
α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
A : ∀ (i : ι), LipschitzWith 1 fun x => x i
this : ∀ (i : ι), ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ (fun x => f x i) s x
x : ℝ
hx : ∀ (i : ι), x ∈ s → DifferentiableWithinAt ℝ (fun x => f x i) s x
xs : x ∈ s
⊢ DifferentiableWithinAt ℝ f s x
tactic: filter_upwards [ae_all_iff.2 this] with x hx xs
state_before: case h
α : Type u_1
inst✝⁵ : LinearOrder α
E : Type u_2
inst✝⁴ : PseudoEMetricSpace E
V : Type u_3
inst✝³ : NormedAddCommGroup V
inst✝² : NormedSpace ℝ V
inst✝¹ : FiniteDimensional ℝ V
ι : Type u_4
inst✝ : Fintype ι
f : ℝ → ι → ℝ
s : Set ℝ
h : LocallyBoundedVariationOn f s
A : ∀ (i : ι), LipschitzWith 1 fun x => x i
this : ∀ (i : ι), ∀ᵐ (x : ℝ), x ∈ s → DifferentiableWithinAt ℝ (fun x => f x i) s x
x : ℝ
hx : ∀ (i : ι), x ∈ s → DifferentiableWithinAt ℝ (fun x => f x i) s x
xs : x ∈ s
⊢ DifferentiableWithinAt ℝ f s x
state_after: no goals
tactic: exact differentiableWithinAt_pi.2 fun i => hx i xs