Theorem: Antitone.tendsto_setIntegral
File: Mathlib/MeasureTheory/Integral/DominatedConvergence.lean

Proof steps:
state_before: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
⊢ Tendsto (fun i => ∫ (a : α) in s i, f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
state_after: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
⊢ Tendsto (fun i => ∫ (a : α) in s i, f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
tactic: let bound : α → ℝ := indicator (s 0) fun a => ‖f a‖
state_before: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
⊢ Tendsto (fun i => ∫ (a : α) in s i, f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
state_after: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Tendsto (fun i => ∫ (a : α) in s i, f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
tactic: have h_int_eq : (fun i => ∫ a in s i, f a ∂μ) = fun i => ∫ a, (s i).indicator f a ∂μ :=
    funext fun i => (integral_indicator (hsm i)).symm
state_before: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Tendsto (fun i => ∫ (a : α) in s i, f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
state_after: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Tendsto (fun i => ∫ (a : α), (s i).indicator f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
tactic: rw [h_int_eq]
state_before: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Tendsto (fun i => ∫ (a : α), (s i).indicator f a ∂μ) atTop (𝓝 (∫ (a : α) in ⋂ n, s n, f a ∂μ))
state_after: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Tendsto (fun i => ∫ (a : α), (s i).indicator f a ∂μ) atTop (𝓝 (∫ (x : α), (⋂ b, s b).indicator f x ∂μ))
tactic: rw [← integral_indicator (MeasurableSet.iInter hsm)]
state_before: α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Tendsto (fun i => ∫ (a : α), (s i).indicator f a ∂μ) atTop (𝓝 (∫ (x : α), (⋂ b, s b).indicator f x ∂μ))
state_after: case refine_1
α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ ∀ (n : ℕ), AEStronglyMeasurable ((s n).indicator f) μ

case refine_2
α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ Integrable bound μ

case refine_3
α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ ∀ (n : ℕ), ∀ᵐ (a : α) ∂μ, ‖(s n).indicator f a‖ ≤ bound a

case refine_4
α : Type u_1
E : Type u_2
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : ℕ → Set α
f : α → E
hsm : ∀ (i : ℕ), MeasurableSet (s i)
h_anti : Antitone s
hfi : IntegrableOn f (s 0) μ
bound : α → ℝ := (s 0).indicator fun a => ‖f a‖
h_int_eq : (fun i => ∫ (a : α) in s i, f a ∂μ) = fun i => ∫ (a : α), (s i).indicator f a ∂μ
⊢ ∀ᵐ (a : α) ∂μ, Tendsto (fun n => (s n).indicator f a) atTop (𝓝 ((⋂ b, s b).indicator f a))
tactic: refine tendsto_integral_of_dominated_convergence bound ?_ ?_ ?_ ?_