Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.CondexpL2

Goal state before:
pp: case refine_1
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ IntegrableOn (↑↑f) s μ

pp: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ StronglyMeasurable g

pp: case refine_3
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ IntegrableOn g s μ

pp: case refine_4
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ ∀ (t : Set α), MeasurableSet t → μ t < ∞ → ∫ (x : α) in t, g x ∂μ = ∫ (x : α) in t, ↑↑f x ∂μ

Tactic:
· exact integrableOn_Lp_of_measure_ne_top f fact_one_le_two_ennreal.elim hμs

Goal state after:
case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ StronglyMeasurable g

case refine_3
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ IntegrableOn g s μ

case refine_4
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
f : ↥(Lp ℝ 2 μ)
h_meas : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) f)) μ := lpMeas.aestronglyMeasurable ((condExpL2 ℝ ℝ hm) f)
g : α → ℝ := Exists.choose h_meas
hg_meas : StronglyMeasurable g
hg_eq : g =ᵐ[μ] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_eq_restrict : g =ᵐ[μ.restrict s] ↑↑↑((condExpL2 ℝ ℝ hm) f)
hg_nnnorm_eq : (fun x ↦ ↑‖g x‖₊) =ᵐ[μ.restrict s] fun x ↦ ↑‖↑↑↑((condExpL2 ℝ ℝ hm) f) x‖₊
⊢ ∀ (t : Set α), MeasurableSet t → μ t < ∞ → ∫ (x : α) in t, g x ∂μ = ∫ (x : α) in t, ↑↑f x ∂μ