Theorem: MeasureTheory.rnDeriv_ae_eq_condexp
File: Mathlib/MeasureTheory/Function/ConditionalExpectation/Real.lean

tactic: refine ae_eq_condexp_of_forall_setIntegral_eq hm hf ?_ ?_ ?_
state_before: α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) =ᶠ[ae μ] μ[f|m]
state_after: case refine_1
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ ∀ (s : Set α),
    MeasurableSet s → μ s < ⊤ → IntegrableOn (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm)) s μ

case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ ∀ (s : Set α),
    MeasurableSet s →
      μ s < ⊤ →
        ∫ (x : α) in s, SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) x ∂μ = ∫ (x : α) in s, f x ∂μ

case refine_3
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ AEStronglyMeasurable' m (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm)) μ

tactic: exact fun _ _ _ => (integrable_of_integrable_trim hm
  (SignedMeasure.integrable_rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm))).integrableOn
state_before: case refine_1
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ ∀ (s : Set α),
    MeasurableSet s → μ s < ⊤ → IntegrableOn (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm)) s μ
state_after: no goals

tactic: intro s hs _
state_before: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ ∀ (s : Set α),
    MeasurableSet s →
      μ s < ⊤ →
        ∫ (x : α) in s, SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) x ∂μ = ∫ (x : α) in s, f x ∂μ
state_after: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
s : Set α
hs : MeasurableSet s
a✝ : μ s < ⊤
⊢ ∫ (x : α) in s, SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) x ∂μ = ∫ (x : α) in s, f x ∂μ

tactic: conv_rhs => rw [← hf.withDensityᵥ_trim_eq_integral hm hs,
  ← SignedMeasure.withDensityᵥ_rnDeriv_eq ((μ.withDensityᵥ f).trim hm) (μ.trim hm)
    (hf.withDensityᵥ_trim_absolutelyContinuous hm)]
state_before: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
s : Set α
hs : MeasurableSet s
a✝ : μ s < ⊤
⊢ ∫ (x : α) in s, SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) x ∂μ = ∫ (x : α) in s, f x ∂μ
state_after: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
s : Set α
hs : MeasurableSet s
a✝ : μ s < ⊤
⊢ ∫ (x : α) in s, SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) x ∂μ =
    ↑((μ.trim hm).withDensityᵥ (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm))) s

tactic: rw [withDensityᵥ_apply
  (SignedMeasure.integrable_rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm)) hs,
  ← setIntegral_trim hm _ hs]
state_before: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
s : Set α
hs : MeasurableSet s
a✝ : μ s < ⊤
⊢ ∫ (x : α) in s, SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm) x ∂μ =
    ↑((μ.trim hm).withDensityᵥ (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm))) s
state_after: α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
s : Set α
hs : MeasurableSet s
a✝ : μ s < ⊤
⊢ StronglyMeasurable (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm))

tactic: exact (SignedMeasure.measurable_rnDeriv _ _).stronglyMeasurable
state_before: α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
s : Set α
hs : MeasurableSet s
a✝ : μ s < ⊤
⊢ StronglyMeasurable (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm))
state_after: no goals

tactic: exact (SignedMeasure.measurable_rnDeriv _ _).stronglyMeasurable.aeStronglyMeasurable'
state_before: case refine_3
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
hμm : SigmaFinite (μ.trim hm)
f : α → ℝ
hf : Integrable f μ
⊢ AEStronglyMeasurable' m (SignedMeasure.rnDeriv ((μ.withDensityᵥ f).trim hm) (μ.trim hm)) μ
state_after: no goals