Theorem: MeasureTheory.Measure.rnDeriv_withDensity_right_of_absolutelyContinuous
File: Mathlib/MeasureTheory/Decomposition/RadonNikodym.lean

tactic: have : SigmaFinite (ν.withDensity f) := SigmaFinite.withDensity_of_ne_top hf hf_ne_top
state_before: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
⊢ μ.rnDeriv (ν.withDensity f) =ᶠ[ae ν] fun x => (f x)⁻¹ * μ.rnDeriv ν x
state_after: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ μ.rnDeriv (ν.withDensity f) =ᶠ[ae ν] fun x => (f x)⁻¹ * μ.rnDeriv ν x

tactic: refine (withDensity_absolutelyContinuous' hf hf_ne_zero).ae_eq ?_
state_before: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ μ.rnDeriv (ν.withDensity f) =ᶠ[ae ν] fun x => (f x)⁻¹ * μ.rnDeriv ν x
state_after: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ μ.rnDeriv (ν.withDensity f) =ᶠ[ae (ν.withDensity f)] fun x => (f x)⁻¹ * μ.rnDeriv ν x

tactic: refine (Measure.eq_rnDeriv₀ (ν := ν.withDensity f) ?_ Measure.MutuallySingular.zero_left ?_).symm
state_before: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ μ.rnDeriv (ν.withDensity f) =ᶠ[ae (ν.withDensity f)] fun x => (f x)⁻¹ * μ.rnDeriv ν x
state_after: case refine_1
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ AEMeasurable (fun x => (f x)⁻¹ * μ.rnDeriv ν x) (ν.withDensity f)

case refine_2
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ μ = 0 + (ν.withDensity f).withDensity fun x => (f x)⁻¹ * μ.rnDeriv ν x

tactic: exact (hf.inv.mono_ac (withDensity_absolutelyContinuous _ _)).mul
  (Measure.measurable_rnDeriv _ _).aemeasurable
state_before: case refine_1
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ AEMeasurable (fun x => (f x)⁻¹ * μ.rnDeriv ν x) (ν.withDensity f)
state_after: no goals

tactic: ext1 s hs
state_before: case refine_2
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
⊢ μ = 0 + (ν.withDensity f).withDensity fun x => (f x)⁻¹ * μ.rnDeriv ν x
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ μ s = (0 + (ν.withDensity f).withDensity fun x => (f x)⁻¹ * μ.rnDeriv ν x) s

tactic: conv_lhs => rw [← Measure.withDensity_rnDeriv_eq _ _ hμν]
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ μ s = (0 + (ν.withDensity f).withDensity fun x => (f x)⁻¹ * μ.rnDeriv ν x) s
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ (ν.withDensity (μ.rnDeriv ν)) s = (0 + (ν.withDensity f).withDensity fun x => (f x)⁻¹ * μ.rnDeriv ν x) s

tactic: rw [zero_add, withDensity_apply _ hs, withDensity_apply _ hs]
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ (ν.withDensity (μ.rnDeriv ν)) s = (0 + (ν.withDensity f).withDensity fun x => (f x)⁻¹ * μ.rnDeriv ν x) s
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, (f a)⁻¹ * μ.rnDeriv ν a ∂ν.withDensity f

tactic: rw [setLIntegral_withDensity_eq_setLIntegral_mul_non_measurable₀ _ _ _ hs]
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, (f a)⁻¹ * μ.rnDeriv ν a ∂ν.withDensity f
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, (f * fun a => (f a)⁻¹ * μ.rnDeriv ν a) a ∂ν

case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∀ᵐ (x : α) ∂ν.restrict s, f x < ⊤

α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ AEMeasurable f (ν.restrict s)

tactic: simp only [Pi.mul_apply]
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, (f * fun a => (f a)⁻¹ * μ.rnDeriv ν a) a ∂ν
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, f a * ((f a)⁻¹ * μ.rnDeriv ν a) ∂ν

tactic: have : (fun a ↦ f a * ((f a)⁻¹ * μ.rnDeriv ν a)) =ᵐ[ν] μ.rnDeriv ν := by
  filter_upwards [hf_ne_zero, hf_ne_top] with x hx1 hx2
  simp [← mul_assoc, ENNReal.mul_inv_cancel, hx1, hx2]
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, f a * ((f a)⁻¹ * μ.rnDeriv ν a) ∂ν
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this✝ : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
this : (fun a => f a * ((f a)⁻¹ * μ.rnDeriv ν a)) =ᶠ[ae ν] μ.rnDeriv ν
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, f a * ((f a)⁻¹ * μ.rnDeriv ν a) ∂ν

tactic: rw [lintegral_congr_ae (ae_restrict_of_ae this)]
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this✝ : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
this : (fun a => f a * ((f a)⁻¹ * μ.rnDeriv ν a)) =ᶠ[ae ν] μ.rnDeriv ν
⊢ ∫⁻ (a : α) in s, μ.rnDeriv ν a ∂ν = ∫⁻ (a : α) in s, f a * ((f a)⁻¹ * μ.rnDeriv ν a) ∂ν
state_after: no goals

tactic: filter_upwards [hf_ne_zero, hf_ne_top] with x hx1 hx2
state_before: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ (fun a => f a * ((f a)⁻¹ * μ.rnDeriv ν a)) =ᶠ[ae ν] μ.rnDeriv ν
state_after: case h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
x : α
hx1 : f x ≠ 0
hx2 : f x ≠ ⊤
⊢ f x * ((f x)⁻¹ * μ.rnDeriv ν x) = μ.rnDeriv ν x

tactic: simp [← mul_assoc, ENNReal.mul_inv_cancel, hx1, hx2]
state_before: case h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
x : α
hx1 : f x ≠ 0
hx2 : f x ≠ ⊤
⊢ f x * ((f x)⁻¹ * μ.rnDeriv ν x) = μ.rnDeriv ν x
state_after: no goals

tactic: refine ae_restrict_of_ae ?_
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∀ᵐ (x : α) ∂ν.restrict s, f x < ⊤
state_after: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∀ᵐ (x : α) ∂ν, f x < ⊤

tactic: filter_upwards [hf_ne_top] with x hx using hx.lt_top
state_before: case refine_2.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ ∀ᵐ (x : α) ∂ν, f x < ⊤
state_after: no goals

tactic: exact hf.restrict
state_before: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ✝ ν✝¹ μ ν✝ : Measure α
f : α → ℝ≥0∞
ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : AEMeasurable f ν
hf_ne_zero : ∀ᵐ (x : α) ∂ν, f x ≠ 0
hf_ne_top : ∀ᵐ (x : α) ∂ν, f x ≠ ⊤
this : SigmaFinite (ν.withDensity f)
s : Set α
hs : MeasurableSet s
⊢ AEMeasurable f (ν.restrict s)
state_after: no goals