Theorem: Measurable.lintegral_prod_right'
File: Mathlib/MeasureTheory/Constructions/Prod/Basic.lean

Proof steps:
state_before: α : Type u_1
α' : Type u_2
β : Type u_3
β' : Type u_4
γ : Type u_5
E : Type u_6
inst✝⁶ : MeasurableSpace α
inst✝⁵ : MeasurableSpace α'
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace β'
inst✝² : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝¹ : NormedAddCommGroup E
inst✝ : SFinite ν
⊢ ∀ {f : α × β → ℝ≥0∞}, Measurable f → Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν
state_after: α : Type u_1
α' : Type u_2
β : Type u_3
β' : Type u_4
γ : Type u_5
E : Type u_6
inst✝⁶ : MeasurableSpace α
inst✝⁵ : MeasurableSpace α'
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace β'
inst✝² : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝¹ : NormedAddCommGroup E
inst✝ : SFinite ν
m :
  ∀ {α : Type ?u.28006} {β : Type ?u.28005} {m : MeasurableSpace α} {mβ : MeasurableSpace β} {x : α},
    Measurable (Prod.mk x)
⊢ ∀ {f : α × β → ℝ≥0∞}, Measurable f → Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν
tactic: have m := @measurable_prod_mk_left
state_before: α : Type u_1
α' : Type u_2
β : Type u_3
β' : Type u_4
γ : Type u_5
E : Type u_6
inst✝⁶ : MeasurableSpace α
inst✝⁵ : MeasurableSpace α'
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace β'
inst✝² : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝¹ : NormedAddCommGroup E
inst✝ : SFinite ν
m :
  ∀ {α : Type ?u.28006} {β : Type ?u.28005} {m : MeasurableSpace α} {mβ : MeasurableSpace β} {x : α},
    Measurable (Prod.mk x)
⊢ ∀ {f : α × β → ℝ≥0∞}, Measurable f → Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν
state_after: case refine_1
α : Type u_1
α' : Type u_2
β : Type u_3
β' : Type u_4
γ : Type u_5
E : Type u_6
inst✝⁶ : MeasurableSpace α
inst✝⁵ : MeasurableSpace α'
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace β'
inst✝² : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝¹ : NormedAddCommGroup E
inst✝ : SFinite ν
m :
  ∀ {α : Type ?u.28006} {β : Type ?u.28005} {m : MeasurableSpace α} {mβ : MeasurableSpace β} {x : α},
    Measurable (Prod.mk x)
⊢ ∀ (c : ℝ≥0∞) ⦃s : Set (α × β)⦄,
    MeasurableSet s → (fun f => Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν) (s.indicator fun x => c)

case refine_2
α : Type u_1
α' : Type u_2
β : Type u_3
β' : Type u_4
γ : Type u_5
E : Type u_6
inst✝⁶ : MeasurableSpace α
inst✝⁵ : MeasurableSpace α'
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace β'
inst✝² : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝¹ : NormedAddCommGroup E
inst✝ : SFinite ν
m :
  ∀ {α : Type ?u.28006} {β : Type ?u.28005} {m : MeasurableSpace α} {mβ : MeasurableSpace β} {x : α},
    Measurable (Prod.mk x)
⊢ ∀ ⦃f g : α × β → ℝ≥0∞⦄,
    Disjoint (support f) (support g) →
      Measurable f →
        Measurable g →
          (fun f => Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν) f →
            (fun f => Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν) g →
              (fun f => Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν) (f + g)

case refine_3
α : Type u_1
α' : Type u_2
β : Type u_3
β' : Type u_4
γ : Type u_5
E : Type u_6
inst✝⁶ : MeasurableSpace α
inst✝⁵ : MeasurableSpace α'
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace β'
inst✝² : MeasurableSpace γ
μ μ' : Measure α
ν ν' : Measure β
τ : Measure γ
inst✝¹ : NormedAddCommGroup E
inst✝ : SFinite ν
m :
  ∀ {α : Type ?u.28006} {β : Type ?u.28005} {m : MeasurableSpace α} {mβ : MeasurableSpace β} {x : α},
    Measurable (Prod.mk x)
⊢ ∀ ⦃f : ℕ → α × β → ℝ≥0∞⦄,
    (∀ (n : ℕ), Measurable (f n)) →
      Monotone f →
        (∀ (n : ℕ), (fun f => Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν) (f n)) →
          (fun f => Measurable fun x => ∫⁻ (y : β), f (x, y) ∂ν) fun x => ⨆ n, f n x
tactic: refine Measurable.ennreal_induction (P := fun f => Measurable fun (x : α) => ∫⁻ y, f (x, y) ∂ν)
    ?_ ?_ ?_