Theorem: MeasureTheory.StronglyMeasurable.integral_prod_right
File: Mathlib/MeasureTheory/Constructions/Prod/Integral.lean

tactic: borelize E
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: haveI : SeparableSpace (range (uncurry f) ∪ {0} : Set E) :=
  hf.separableSpace_range_union_singleton
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: let s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn _ hf.measurable (range (uncurry f) ∪ {0}) 0 (by simp)
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: let s' : ℕ → α → SimpleFunc β E := fun n x => (s n).comp (Prod.mk x) measurable_prod_mk_left
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: let f' : ℕ → α → E := fun n => {x | Integrable (f x) ν}.indicator fun x => (s' n x).integral ν
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: have hf' : ∀ n, StronglyMeasurable (f' n) := by
  intro n; refine' StronglyMeasurable.indicator _ (measurableSet_integrable hf)
  have : ∀ x, ((s' n x).range.filter fun x => x ≠ 0) ⊆ (s n).range := by
    intro x; refine' Finset.Subset.trans (Finset.filter_subset _ _) _; intro y
    simp_rw [SimpleFunc.mem_range]; rintro ⟨z, rfl⟩; exact ⟨(x, z), rfl⟩
  simp only [SimpleFunc.integral_eq_sum_of_subset (this _)]
  refine' Finset.stronglyMeasurable_sum _ fun x _ => _
  refine' (Measurable.ennreal_toReal _).stronglyMeasurable.smul_const _
  simp (config := { singlePass := true }) only [SimpleFunc.coe_comp, preimage_comp]
  apply measurable_measure_prod_mk_left
  exact (s n).measurableSet_fiber x
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: exact stronglyMeasurable_of_tendsto _ hf' h2f'
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
h2f' : Tendsto f' atTop (𝓝 fun x => ∫ (y : β), f x y ∂ν)
⊢ StronglyMeasurable fun x => ∫ (y : β), f x y ∂ν

tactic: simp
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
⊢ 0 ∈ range (uncurry f) ∪ {0}

tactic: intro n
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
⊢ ∀ (n : ℕ), StronglyMeasurable (f' n)

tactic: refine' StronglyMeasurable.indicator _ (measurableSet_integrable hf)
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
⊢ StronglyMeasurable (f' n)

tactic: have : ∀ x, ((s' n x).range.filter fun x => x ≠ 0) ⊆ (s n).range := by
  intro x; refine' Finset.Subset.trans (Finset.filter_subset _ _) _; intro y
  simp_rw [SimpleFunc.mem_range]; rintro ⟨z, rfl⟩; exact ⟨(x, z), rfl⟩
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
⊢ StronglyMeasurable fun x => SimpleFunc.integral ν (s' n x)

tactic: simp only [SimpleFunc.integral_eq_sum_of_subset (this _)]
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
this : ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)
⊢ StronglyMeasurable fun x => SimpleFunc.integral ν (s' n x)

tactic: refine' Finset.stronglyMeasurable_sum _ fun x _ => _
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
this : ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)
⊢ StronglyMeasurable fun x =>
    Finset.sum
      (SimpleFunc.range
        (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
          (_ : 0 ∈ range (uncurry f) ∪ {0}) n))
      fun x_1 =>
      ENNReal.toReal
          (↑↑ν
            (↑(SimpleFunc.comp
                  (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
                    (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
                  (Prod.mk x) (_ : Measurable (Prod.mk x))) ⁻¹'
              {x_1})) •
        x_1

tactic: refine' (Measurable.ennreal_toReal _).stronglyMeasurable.smul_const _
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
this : ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)
x : E
x✝ :
  x ∈
    SimpleFunc.range
      (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
        (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
⊢ StronglyMeasurable fun x_1 =>
    ENNReal.toReal
        (↑↑ν
          (↑(SimpleFunc.comp
                (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
                  (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
                (Prod.mk x_1) (_ : Measurable (Prod.mk x_1))) ⁻¹'
            {x})) •
      x

tactic: simp (config := { singlePass := true }) only [SimpleFunc.coe_comp, preimage_comp]
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
this : ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)
x : E
x✝ :
  x ∈
    SimpleFunc.range
      (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
        (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
⊢ Measurable fun x_1 =>
    ↑↑ν
      (↑(SimpleFunc.comp
            (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
              (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
            (Prod.mk x_1) (_ : Measurable (Prod.mk x_1))) ⁻¹'
        {x})

tactic: apply measurable_measure_prod_mk_left
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
this : ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)
x : E
x✝ :
  x ∈
    SimpleFunc.range
      (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
        (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
⊢ Measurable fun x_1 =>
    ↑↑ν
      (Prod.mk x_1 ⁻¹'
        (↑(SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
              (_ : 0 ∈ range (uncurry f) ∪ {0}) n) ⁻¹'
          {x}))

tactic: exact (s n).measurableSet_fiber x
state_before: case hs
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
this : ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)
x : E
x✝ :
  x ∈
    SimpleFunc.range
      (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
        (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
⊢ MeasurableSet
    (↑(SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
          (_ : 0 ∈ range (uncurry f) ∪ {0}) n) ⁻¹'
      {x})

tactic: intro x
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
⊢ ∀ (x : α), Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)

tactic: refine' Finset.Subset.trans (Finset.filter_subset _ _) _
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
x : α
⊢ Finset.filter (fun x => x ≠ 0) (SimpleFunc.range (s' n x)) ⊆ SimpleFunc.range (s n)

tactic: intro y
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
x : α
⊢ SimpleFunc.range (s' n x) ⊆ SimpleFunc.range (s n)

tactic: simp_rw [SimpleFunc.mem_range]
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
x : α
y : E
⊢ y ∈ SimpleFunc.range (s' n x) → y ∈ SimpleFunc.range (s n)

tactic: rintro ⟨z, rfl⟩
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
x : α
y : E
⊢ y ∈
      range
        ↑(SimpleFunc.comp
            (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
              (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
            (Prod.mk x) (_ : Measurable (Prod.mk x))) →
    y ∈
      range
        ↑(SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
            (_ : 0 ∈ range (uncurry f) ∪ {0}) n)

tactic: exact ⟨(x, z), rfl⟩
state_before: case intro
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
n : ℕ
x : α
z : β
⊢ ↑(SimpleFunc.comp
          (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
            (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
          (Prod.mk x) (_ : Measurable (Prod.mk x)))
      z ∈
    range
      ↑(SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
          (_ : 0 ∈ range (uncurry f) ∪ {0}) n)

tactic: rw [tendsto_pi_nhds]
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
⊢ Tendsto f' atTop (𝓝 fun x => ∫ (y : β), f x y ∂ν)

tactic: intro x
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
⊢ ∀ (x : α), Tendsto (fun i => f' i x) atTop (𝓝 (∫ (y : β), f x y ∂ν))

tactic: by_cases hfx : Integrable (f x) ν
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
⊢ Tendsto (fun i => f' i x) atTop (𝓝 (∫ (y : β), f x y ∂ν))

tactic: have : ∀ n, Integrable (s' n x) ν := by
  intro n; apply (hfx.norm.add hfx.norm).mono' (s' n x).aestronglyMeasurable
  apply eventually_of_forall; intro y
  simp_rw [SimpleFunc.coe_comp]; exact SimpleFunc.norm_approxOn_zero_le _ _ (x, y) n
state_before: case pos
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
⊢ Tendsto (fun i => f' i x) atTop (𝓝 (∫ (y : β), f x y ∂ν))

tactic: simp only [hfx, SimpleFunc.integral_eq_integral _ (this _), indicator_of_mem,
  mem_setOf_eq]
state_before: case pos
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
⊢ Tendsto (fun i => f' i x) atTop (𝓝 (∫ (y : β), f x y ∂ν))

tactic: refine'
  tendsto_integral_of_dominated_convergence (fun y => ‖f x y‖ + ‖f x y‖)
    (fun n => (s' n x).aestronglyMeasurable) (hfx.norm.add hfx.norm) _ _
state_before: case pos
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
⊢ Tendsto
    (fun i =>
      ∫ (x_1 : β),
        ↑(SimpleFunc.comp
              (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
                (_ : 0 ∈ range (uncurry f) ∪ {0}) i)
              (Prod.mk x) (_ : Measurable (Prod.mk x)))
          x_1 ∂ν)
    atTop (𝓝 (∫ (y : β), f x y ∂ν))

tactic: intro n
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
⊢ ∀ (n : ℕ), Integrable ↑(s' n x)

tactic: apply (hfx.norm.add hfx.norm).mono' (s' n x).aestronglyMeasurable
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
n : ℕ
⊢ Integrable ↑(s' n x)

tactic: apply eventually_of_forall
state_before: α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
n : ℕ
⊢ ∀ᵐ (a : β) ∂ν, ‖↑(s' n x) a‖ ≤ ((fun a => ‖f x a‖) + fun a => ‖f x a‖) a

tactic: intro y
state_before: case hp
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
n : ℕ
⊢ ∀ (x_1 : β), ‖↑(s' n x) x_1‖ ≤ ((fun a => ‖f x a‖) + fun a => ‖f x a‖) x_1

tactic: simp_rw [SimpleFunc.coe_comp]
state_before: case hp
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
n : ℕ
y : β
⊢ ‖↑(s' n x) y‖ ≤ ((fun a => ‖f x a‖) + fun a => ‖f x a‖) y

tactic: exact SimpleFunc.norm_approxOn_zero_le _ _ (x, y) n
state_before: case hp
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
n : ℕ
y : β
⊢ ‖(↑(SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
              (_ : 0 ∈ range (uncurry f) ∪ {0}) n) ∘
          Prod.mk x)
        y‖ ≤
    ((fun a => ‖f x a‖) + fun a => ‖f x a‖) y

tactic: refine' fun n => eventually_of_forall fun y => SimpleFunc.norm_approxOn_zero_le _ _ (x, y) n
state_before: case pos.refine'_1
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
⊢ ∀ (n : ℕ),
    ∀ᵐ (a : β) ∂ν,
      ‖↑(SimpleFunc.comp
                (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
                  (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
                (Prod.mk x) (_ : Measurable (Prod.mk x)))
            a‖ ≤
        (fun y => ‖f x y‖ + ‖f x y‖) a

tactic: exact hf.measurable
state_before: case pos.refine'_1.refine'_1
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
n : ℕ
y : β
⊢ Measurable (uncurry f)

tactic: simp
state_before: case pos.refine'_1.refine'_2
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
n : ℕ
y : β
⊢ 0 ∈ range (uncurry f) ∪ {0}

tactic: refine' eventually_of_forall fun y => SimpleFunc.tendsto_approxOn _ _ _
state_before: case pos.refine'_2
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
⊢ ∀ᵐ (a : β) ∂ν,
    Tendsto
      (fun n =>
        ↑(SimpleFunc.comp
              (SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
                (_ : 0 ∈ range (uncurry f) ∪ {0}) n)
              (Prod.mk x) (_ : Measurable (Prod.mk x)))
          a)
      atTop (𝓝 (f x a))

tactic: apply subset_closure
state_before: case pos.refine'_2.refine'_3
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
y : β
⊢ uncurry f (x, y) ∈ closure (range (uncurry f) ∪ {0})

tactic: simp [-uncurry_apply_pair]
state_before: case pos.refine'_2.refine'_3.a
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
y : β
⊢ uncurry f (x, y) ∈ range (uncurry f) ∪ {0}

tactic: exact hf.measurable.of_uncurry_left
state_before: case pos.refine'_2.refine'_1
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
y : β
⊢ Measurable fun x_1 => uncurry f (x, x_1)

tactic: simp
state_before: case pos.refine'_2.refine'_2
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝² : MeasurableSpace E := borel E
this✝¹ : BorelSpace E
this✝ : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : Integrable (f x)
this : ∀ (n : ℕ), Integrable ↑(s' n x)
y : β
⊢ 0 ∈ range (uncurry f) ∪ {0}

tactic: simp [hfx, integral_undef]
state_before: case neg
α : Type u_2
α' : Type ?u.2296206
β : Type u_1
β' : Type ?u.2296212
γ : Type ?u.2296215
E : Type u_3
inst✝⁸ : MeasurableSpace α
inst✝⁷ : MeasurableSpace α'
inst✝⁶ : MeasurableSpace β
inst✝⁵ : MeasurableSpace β'
inst✝⁴ : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝³ : NormedAddCommGroup E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SigmaFinite ν
f : α → β → E
hf : StronglyMeasurable (uncurry f)
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
this : SeparableSpace ↑(range (uncurry f) ∪ {0})
s : ℕ → SimpleFunc (α × β) E :=
  SimpleFunc.approxOn (uncurry f) (_ : Measurable (uncurry f)) (range (uncurry f) ∪ {0}) 0
    (_ : 0 ∈ range (uncurry f) ∪ {0})
s' : ℕ → α → SimpleFunc β E := fun n x => SimpleFunc.comp (s n) (Prod.mk x) (_ : Measurable (Prod.mk x))
f' : ℕ → α → E := fun n => indicator {x | Integrable (f x)} fun x => SimpleFunc.integral ν (s' n x)
hf' : ∀ (n : ℕ), StronglyMeasurable (f' n)
x : α
hfx : ¬Integrable (f x)
⊢ Tendsto (fun i => f' i x) atTop (𝓝 (∫ (y : β), f x y ∂ν))