Module: Mathlib.Probability.Independence.Kernel.IndepFun

Goal state before:
pp: case refine_2.refine_1
α : Type u_1
Ω : Type u_2
β : Type u_4
γ : Type u_6
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteKernel κ
f : Ω → β
g : Ω → γ
hf : Measurable f
hg : Measurable g
h :
  ∀ {s : Set α} {t : Set β} {u : Set γ},
    MeasurableSet s →
      MeasurableSet t →
        MeasurableSet u → (μ ⊗ₘ κ.map fun ω ↦ (f ω, g ω)) (s ×ˢ t ×ˢ u) = (μ ⊗ₘ (κ.map f ×ₖ κ.map g)) (s ×ˢ t ×ˢ u)
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
⊢ Measurable fun a ↦ (κ a) (f ⁻¹' s ∩ g ⁻¹' t)

pp: case refine_2.refine_2
α : Type u_1
Ω : Type u_2
β : Type u_4
γ : Type u_6
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteKernel κ
f : Ω → β
g : Ω → γ
hf : Measurable f
hg : Measurable g
h :
  ∀ {s : Set α} {t : Set β} {u : Set γ},
    MeasurableSet s →
      MeasurableSet t →
        MeasurableSet u → (μ ⊗ₘ κ.map fun ω ↦ (f ω, g ω)) (s ×ˢ t ×ˢ u) = (μ ⊗ₘ (κ.map f ×ₖ κ.map g)) (s ×ˢ t ×ˢ u)
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
⊢ Measurable fun a ↦ (κ a) (f ⁻¹' s) * (κ a) (g ⁻¹' t)

pp: case refine_2.refine_3
α : Type u_1
Ω : Type u_2
β : Type u_4
γ : Type u_6
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteKernel κ
f : Ω → β
g : Ω → γ
hf : Measurable f
hg : Measurable g
h :
  ∀ {s : Set α} {t : Set β} {u : Set γ},
    MeasurableSet s →
      MeasurableSet t →
        MeasurableSet u → (μ ⊗ₘ κ.map fun ω ↦ (f ω, g ω)) (s ×ˢ t ×ˢ u) = (μ ⊗ₘ (κ.map f ×ₖ κ.map g)) (s ×ˢ t ×ˢ u)
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
⊢ ∀ (s_1 : Set α),
    MeasurableSet s_1 →
      μ s_1 < ⊤ →
        ∫⁻ (x : α) in s_1, (κ x) (f ⁻¹' s ∩ g ⁻¹' t) ∂μ = ∫⁻ (x : α) in s_1, (κ x) (f ⁻¹' s) * (κ x) (g ⁻¹' t) ∂μ

Tactic:
· exact Kernel.measurable_coe _ ((hf hs).inter (hg ht))

Goal state after:
case refine_2.refine_2
α : Type u_1
Ω : Type u_2
β : Type u_4
γ : Type u_6
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteKernel κ
f : Ω → β
g : Ω → γ
hf : Measurable f
hg : Measurable g
h :
  ∀ {s : Set α} {t : Set β} {u : Set γ},
    MeasurableSet s →
      MeasurableSet t →
        MeasurableSet u → (μ ⊗ₘ κ.map fun ω ↦ (f ω, g ω)) (s ×ˢ t ×ˢ u) = (μ ⊗ₘ (κ.map f ×ₖ κ.map g)) (s ×ˢ t ×ˢ u)
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
⊢ Measurable fun a ↦ (κ a) (f ⁻¹' s) * (κ a) (g ⁻¹' t)

case refine_2.refine_3
α : Type u_1
Ω : Type u_2
β : Type u_4
γ : Type u_6
mα : MeasurableSpace α
mΩ : MeasurableSpace Ω
κ : Kernel α Ω
μ : Measure α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteKernel κ
f : Ω → β
g : Ω → γ
hf : Measurable f
hg : Measurable g
h :
  ∀ {s : Set α} {t : Set β} {u : Set γ},
    MeasurableSet s →
      MeasurableSet t →
        MeasurableSet u → (μ ⊗ₘ κ.map fun ω ↦ (f ω, g ω)) (s ×ˢ t ×ˢ u) = (μ ⊗ₘ (κ.map f ×ₖ κ.map g)) (s ×ˢ t ×ˢ u)
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
⊢ ∀ (s_1 : Set α),
    MeasurableSet s_1 →
      μ s_1 < ⊤ →
        ∫⁻ (x : α) in s_1, (κ x) (f ⁻¹' s ∩ g ⁻¹' t) ∂μ = ∫⁻ (x : α) in s_1, (κ x) (f ⁻¹' s) * (κ x) (g ⁻¹' t) ∂μ