mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Probability.Kernel.Composition.CompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
a : α
u : Set (β × γ)
hu : MeasurableSet u
⊢ ∫⁻ (b : β), ((η.restrict ht) (a, b)) (Prod.mk b ⁻¹' u) ∂(κ.restrict hs) a = ((κ ⊗ₖ η) a) (u ∩ s ×ˢ t)

Tactic:
compProd_apply (hu.inter (hs.prod ht))

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
s : Set β
t : Set γ
hs : MeasurableSet s
ht : MeasurableSet t
a : α
u : Set (β × γ)
hu : MeasurableSet u
⊢ ∫⁻ (b : β), ((η.restrict ht) (a, b)) (Prod.mk b ⁻¹' u) ∂(κ.restrict hs) a =
    ∫⁻ (b : β), (η (a, b)) (Prod.mk b ⁻¹' (u ∩ s ×ˢ t)) ∂κ a
Module: Mathlib.Probability.Kernel.Composition.CompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
a : α
f : β → γ → ℝ≥0∞
hf : Measurable (Function.uncurry f)
F : ℕ → SimpleFunc (β × γ) ℝ≥0∞ := SimpleFunc.eapprox (Function.uncurry f)
h : ∀ (a : β) (b : γ), ⨆ n, (F n) (a, b) = f a b
h_mono : Monotone F
this✝ : ∀ (b : β), ∫⁻ (c : γ), ⨆ n, (F n) (b, c) ∂η (a, b) = ⨆ n, ∫⁻ (c : γ), (F n) (b, c) ∂η (a, b)
f' : SimpleFunc (β × γ) ℝ≥0∞
this : (fun b ↦ ∫⁻ (c : γ), f' (b, c) ∂η (a, b)) = (fun ab ↦ ∫⁻ (c : γ), f' (ab.2, c) ∂η ab) ∘ fun b ↦ (a, b)
⊢ Measurable fun b ↦ ∫⁻ (c : γ), f' (b, c) ∂η (a, b)

Tactic:
rw [this]

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
a : α
f : β → γ → ℝ≥0∞
hf : Measurable (Function.uncurry f)
F : ℕ → SimpleFunc (β × γ) ℝ≥0∞ := SimpleFunc.eapprox (Function.uncurry f)
h : ∀ (a : β) (b : γ), ⨆ n, (F n) (a, b) = f a b
h_mono : Monotone F
this✝ : ∀ (b : β), ∫⁻ (c : γ), ⨆ n, (F n) (b, c) ∂η (a, b) = ⨆ n, ∫⁻ (c : γ), (F n) (b, c) ∂η (a, b)
f' : SimpleFunc (β × γ) ℝ≥0∞
this : (fun b ↦ ∫⁻ (c : γ), f' (b, c) ∂η (a, b)) = (fun ab ↦ ∫⁻ (c : γ), f' (ab.2, c) ∂η ab) ∘ fun b ↦ (a, b)
⊢ Measurable ((fun ab ↦ ∫⁻ (c : γ), f' (ab.2, c) ∂η ab) ∘ fun b ↦ (a, b))
Module: Mathlib.Probability.Kernel.Composition.IntegralCompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝² : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
f : β × γ → E
h1f : StronglyMeasurable f
this : ∀ (x : β), ∀ᵐ (y : γ) ∂η (a, x), 0 ≤ ‖f (x, y)‖
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f (b, c)‖ₑ ∂η (a, b) ∂κ a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f (x, a)‖ₑ ∂η (a, x) < ∞) ∧
      ∫⁻ (a_1 : β), ‖(∫⁻ (a : γ), ENNReal.ofReal ‖f (a_1, a)‖ ∂η (a, a_1)).toReal‖ₑ ∂κ a < ∞

Tactic:
enorm_eq_ofReal toReal_nonneg,

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝² : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
f : β × γ → E
h1f : StronglyMeasurable f
this : ∀ (x : β), ∀ᵐ (y : γ) ∂η (a, x), 0 ≤ ‖f (x, y)‖
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f (b, c)‖ₑ ∂η (a, b) ∂κ a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f (x, a)‖ₑ ∂η (a, x) < ∞) ∧
      ∫⁻ (a_1 : β), ENNReal.ofReal (∫⁻ (a : γ), ENNReal.ofReal ‖f (a_1, a)‖ ∂η (a, a_1)).toReal ∂κ a < ∞
Module: Mathlib.Probability.Kernel.Composition.IntegralCompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝² : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
f : β × γ → E
h1f : StronglyMeasurable f
this✝ : ∀ (x : β), ∀ᵐ (y : γ) ∂η (a, x), 0 ≤ ‖f (x, y)‖
this : ∀ {p q r : Prop}, (r → p) → ((r ↔ p ∧ q) ↔ p → (r ↔ q))
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f (b, c)‖ₑ ∂η (a, b) ∂κ a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f (x, a)‖ₑ ∂η (a, x) < ∞) ∧
      ∫⁻ (a_1 : β), ENNReal.ofReal (∫⁻ (a : γ), ‖f (a_1, a)‖ₑ ∂η (a, a_1)).toReal ∂κ a < ∞

Tactic:
rw [this]

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝² : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
f : β × γ → E
h1f : StronglyMeasurable f
this✝ : ∀ (x : β), ∀ᵐ (y : γ) ∂η (a, x), 0 ≤ ‖f (x, y)‖
this : ∀ {p q r : Prop}, (r → p) → ((r ↔ p ∧ q) ↔ p → (r ↔ q))
⊢ (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f (x, a)‖ₑ ∂η (a, x) < ∞) →
    (∫⁻ (b : β), ∫⁻ (c : γ), ‖f (b, c)‖ₑ ∂η (a, b) ∂κ a < ∞ ↔
      ∫⁻ (a_2 : β), ENNReal.ofReal (∫⁻ (a : γ), ‖f (a_2, a)‖ₑ ∂η (a, a_2)).toReal ∂κ a < ∞)

α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝² : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝¹ : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝ : IsSFiniteKernel η
f : β × γ → E
h1f : StronglyMeasurable f
this✝ : ∀ (x : β), ∀ᵐ (y : γ) ∂η (a, x), 0 ≤ ‖f (x, y)‖
this : ∀ {p q r : Prop}, (r → p) → ((r ↔ p ∧ q) ↔ p → (r ↔ q))
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f (b, c)‖ₑ ∂η (a, b) ∂κ a < ∞ → ∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f (x, a)‖ₑ ∂η (a, x) < ∞
Module: Mathlib.Probability.Kernel.Composition.IntegralCompProd

Goal state before:
pp: case pos.h_ind.e_a
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝³ : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝² : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝¹ : IsSFiniteKernel η
inst✝ : NormedSpace ℝ E
f✝ : β × γ → E
hE : CompleteSpace E
c : E
s : Set (β × γ)
hs : MeasurableSet s
h2s : ((κ ⊗ₖ η) a) s < ∞
⊢ (((κ ⊗ₖ η) a) s).toReal = ∫ (x : β), ((η (a, x)) (Prod.mk x ⁻¹' s)).toReal ∂κ a

Tactic:
integral_toReal

Goal state after:
case pos.h_ind.e_a
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝³ : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝² : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝¹ : IsSFiniteKernel η
inst✝ : NormedSpace ℝ E
f✝ : β × γ → E
hE : CompleteSpace E
c : E
s : Set (β × γ)
hs : MeasurableSet s
h2s : ((κ ⊗ₖ η) a) s < ∞
⊢ (((κ ⊗ₖ η) a) s).toReal = (∫⁻ (a_1 : β), (η (a, a_1)) (Prod.mk a_1 ⁻¹' s) ∂κ a).toReal

case pos.h_ind.e_a.hfm
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝³ : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝² : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝¹ : IsSFiniteKernel η
inst✝ : NormedSpace ℝ E
f✝ : β × γ → E
hE : CompleteSpace E
c : E
s : Set (β × γ)
hs : MeasurableSet s
h2s : ((κ ⊗ₖ η) a) s < ∞
⊢ AEMeasurable (fun x ↦ (η (a, x)) (Prod.mk x ⁻¹' s)) (κ a)

case pos.h_ind.e_a.hf
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝³ : NormedAddCommGroup E
a : α
κ : Kernel α β
inst✝² : IsSFiniteKernel κ
η : Kernel (α × β) γ
inst✝¹ : IsSFiniteKernel η
inst✝ : NormedSpace ℝ E
f✝ : β × γ → E
hE : CompleteSpace E
c : E
s : Set (β × γ)
hs : MeasurableSet s
h2s : ((κ ⊗ₖ η) a) s < ∞
⊢ ∀ᵐ (x : β) ∂κ a, (η (a, x)) (Prod.mk x ⁻¹' s) < ∞
Module: Mathlib.MeasureTheory.Measure.Tilted

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
⊢ IsZeroOrProbabilityMeasure (μ.tilted f)

Tactic:
rcases eq_zero_or_neZero μ with hμ | hμ
  · simp only [hμ, tilted_zero_measure]
    infer_instance
  by_cases hf : Integrable (fun x ↦ exp (f x)) μ
  · have := isProbabilityMeasure_tilted hf
    infer_instance
  · simp only [hf, not_false_eq_true, tilted_of_not_integrable]
    infer_instance

Goal state after:
Module: Mathlib.Probability.Kernel.Composition.CompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
δ : Type u_4
mδ : MeasurableSpace δ
κ : Kernel α β
η : Kernel (α × β) γ
ξ : Kernel (α × β × γ) δ
hκ : IsSFiniteKernel κ
hη : IsSFiniteKernel η
hξ : ¬IsSFiniteKernel ξ
h_sfin : IsSFiniteKernel (ξ.comap ⇑MeasurableEquiv.prodAssoc ⋯)
this : ξ = (ξ.comap ⇑MeasurableEquiv.prodAssoc ⋯).comap ⇑MeasurableEquiv.prodAssoc.symm ⋯
⊢ IsSFiniteKernel ξ

Tactic:
rw [this]

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
δ : Type u_4
mδ : MeasurableSpace δ
κ : Kernel α β
η : Kernel (α × β) γ
ξ : Kernel (α × β × γ) δ
hκ : IsSFiniteKernel κ
hη : IsSFiniteKernel η
hξ : ¬IsSFiniteKernel ξ
h_sfin : IsSFiniteKernel (ξ.comap ⇑MeasurableEquiv.prodAssoc ⋯)
this : ξ = (ξ.comap ⇑MeasurableEquiv.prodAssoc ⋯).comap ⇑MeasurableEquiv.prodAssoc.symm ⋯
⊢ IsSFiniteKernel ((ξ.comap ⇑MeasurableEquiv.prodAssoc ⋯).comap ⇑MeasurableEquiv.prodAssoc.symm ⋯)
Module: Mathlib.Probability.Kernel.Composition.IntegralCompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : NormedAddCommGroup E
a : α
κ : Kernel α β
η : Kernel β γ
f : γ → E
hf : StronglyMeasurable f
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f c‖ₑ ∂η b ∂κ a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f a‖ₑ ∂η x < ∞) ∧
      ∫⁻ (a : β), ‖(∫⁻ (a : γ), ENNReal.ofReal ‖f a‖ ∂η a).toReal‖ₑ ∂κ a < ∞

Tactic:
enorm_eq_ofReal toReal_nonneg,

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : NormedAddCommGroup E
a : α
κ : Kernel α β
η : Kernel β γ
f : γ → E
hf : StronglyMeasurable f
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f c‖ₑ ∂η b ∂κ a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f a‖ₑ ∂η x < ∞) ∧
      ∫⁻ (a : β), ENNReal.ofReal (∫⁻ (a : γ), ENNReal.ofReal ‖f a‖ ∂η a).toReal ∂κ a < ∞
Module: Mathlib.Probability.Kernel.Composition.IntegralCompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : NormedAddCommGroup E
a : α
κ : Kernel α β
η : Kernel β γ
f : γ → E
hf : StronglyMeasurable f
this : ∀ {p q r : Prop}, (r → p) → ((r ↔ p ∧ q) ↔ p → (r ↔ q))
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f c‖ₑ ∂η b ∂κ a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f a‖ₑ ∂η x < ∞) ∧
      ∫⁻ (a : β), ENNReal.ofReal (∫⁻ (a : γ), ‖f a‖ₑ ∂η a).toReal ∂κ a < ∞

Tactic:
rw [this]

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : NormedAddCommGroup E
a : α
κ : Kernel α β
η : Kernel β γ
f : γ → E
hf : StronglyMeasurable f
this : ∀ {p q r : Prop}, (r → p) → ((r ↔ p ∧ q) ↔ p → (r ↔ q))
⊢ (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f a‖ₑ ∂η x < ∞) →
    (∫⁻ (b : β), ∫⁻ (c : γ), ‖f c‖ₑ ∂η b ∂κ a < ∞ ↔
      ∫⁻ (a : β), ENNReal.ofReal (∫⁻ (a : γ), ‖f a‖ₑ ∂η a).toReal ∂κ a < ∞)

α : Type u_1
β : Type u_2
γ : Type u_3
E : Type u_4
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : NormedAddCommGroup E
a : α
κ : Kernel α β
η : Kernel β γ
f : γ → E
hf : StronglyMeasurable f
this : ∀ {p q r : Prop}, (r → p) → ((r ↔ p ∧ q) ↔ p → (r ↔ q))
⊢ ∫⁻ (b : β), ∫⁻ (c : γ), ‖f c‖ₑ ∂η b ∂κ a < ∞ → ∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f a‖ₑ ∂η x < ∞
Module: Mathlib.MeasureTheory.Measure.Tilted

Goal state before:
pp: case pos
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : SFinite μ
f : α → ℝ
g : α → E
s : Set α
hf : AEMeasurable f μ
⊢ ∫ (x : α) in s, g x ∂μ.tilted f = ∫ (x : α) in s, (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) • g x ∂μ

pp: case neg
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : SFinite μ
f : α → ℝ
g : α → E
s : Set α
hf : ¬AEMeasurable f μ
⊢ ∫ (x : α) in s, g x ∂μ.tilted f = ∫ (x : α) in s, (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) • g x ∂μ

Tactic:
· rw [tilted_eq_withDensity_nnreal, setIntegral_withDensity_eq_setIntegral_smul₀']
    · congr
    · suffices AEMeasurable (fun x ↦ exp (f x) / ∫ x, exp (f x) ∂μ) μ by
        rw [← aemeasurable_coe_nnreal_real_iff]
        refine AEMeasurable.restrict ?_
        simpa only [NNReal.coe_mk]
      exact (measurable_exp.comp_aemeasurable hf).div_const _

Goal state after:
case neg
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
E : Type u_2
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : SFinite μ
f : α → ℝ
g : α → E
s : Set α
hf : ¬AEMeasurable f μ
⊢ ∫ (x : α) in s, g x ∂μ.tilted f = ∫ (x : α) in s, (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) • g x ∂μ
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: case neg
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝ : SigmaFinite μ
x : α
hx : μ.rnDeriv ν x < ∞
h_zero : ¬μ.rnDeriv ν x = 0
⊢ rexp (llr μ ν x) = if μ.rnDeriv ν x = 0 then 1 else (μ.rnDeriv ν x).toReal

Tactic:
llr,

Goal state after:
case neg
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝ : SigmaFinite μ
x : α
hx : μ.rnDeriv ν x < ∞
h_zero : ¬μ.rnDeriv ν x = 0
⊢ rexp (log (μ.rnDeriv ν x).toReal) = if μ.rnDeriv ν x = 0 then 1 else (μ.rnDeriv ν x).toReal
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
x : α
hx : (μ.rnDeriv ν)⁻¹ x = ν.rnDeriv μ x
⊢ -llr μ ν x = llr ν μ x

Tactic:
llr,

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
x : α
hx : (μ.rnDeriv ν)⁻¹ x = ν.rnDeriv μ x
⊢ -log (μ.rnDeriv ν x).toReal = llr ν μ x
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
x : α
hx : (μ.rnDeriv ν)⁻¹ x = ν.rnDeriv μ x
⊢ -log (μ.rnDeriv ν x).toReal = llr ν μ x

Tactic:
llr,

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
x : α
hx : (μ.rnDeriv ν)⁻¹ x = ν.rnDeriv μ x
⊢ -log (μ.rnDeriv ν x).toReal = log (ν.rnDeriv μ x).toReal
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
⊢ (fun x ↦ rexp (-llr μ ν x)) =ᵐ[μ] fun x ↦ (ν.rnDeriv μ x).toReal

Tactic:
by
  filter_upwards [neg_llr hμν, exp_llr_of_ac' ν μ hμν] with x hx hx_exp_log
  rw [Pi.neg_apply] at hx
  rw [hx, hx_exp_log]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
f : α → ℝ
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : Integrable (fun x ↦ rexp (f x)) μ
hfν : AEMeasurable f ν
h0 : NeZero μ
x : α
hx : ((μ.tilted f).rnDeriv ν x).toReal = (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) * (μ.rnDeriv ν x).toReal
hx_pos : 0 < μ.rnDeriv ν x
hx_lt_top : μ.rnDeriv ν x < ∞
⊢ llr (μ.tilted f) ν x = f x - log (∫ (z : α), rexp (f z) ∂μ) + llr μ ν x

Tactic:
llr,

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
f : α → ℝ
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : Integrable (fun x ↦ rexp (f x)) μ
hfν : AEMeasurable f ν
h0 : NeZero μ
x : α
hx : ((μ.tilted f).rnDeriv ν x).toReal = (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) * (μ.rnDeriv ν x).toReal
hx_pos : 0 < μ.rnDeriv ν x
hx_lt_top : μ.rnDeriv ν x < ∞
⊢ log ((μ.tilted f).rnDeriv ν x).toReal = f x - log (∫ (z : α), rexp (f z) ∂μ) + llr μ ν x
Module: Mathlib.InformationTheory.KullbackLeibler.KLFun

Goal state before:
pp: this : klFun = fun x ↦ x * (log x - 1) + 1
⊢ Tendsto klFun atTop atTop

Tactic:
rw [this]

Goal state after:
this : klFun = fun x ↦ x * (log x - 1) + 1
⊢ Tendsto (fun x ↦ x * (log x - 1) + 1) atTop atTop
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
f : α → ℝ
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : Integrable (fun x ↦ rexp (f x)) ν
h0 : NeZero ν
x : α
hx : (μ.rnDeriv (ν.tilted f) x).toReal = (rexp (-f x) * ∫ (x : α), rexp (f x) ∂ν) * (μ.rnDeriv ν x).toReal
hx_pos : 0 < μ.rnDeriv ν x
hx_lt_top : μ.rnDeriv ν x < ∞
⊢ llr μ (ν.tilted f) x = -f x + log (∫ (z : α), rexp (f z) ∂ν) + llr μ ν x

Tactic:
llr,

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
f : α → ℝ
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
hμν : μ ≪ ν
hf : Integrable (fun x ↦ rexp (f x)) ν
h0 : NeZero ν
x : α
hx : (μ.rnDeriv (ν.tilted f) x).toReal = (rexp (-f x) * ∫ (x : α), rexp (f x) ∂ν) * (μ.rnDeriv ν x).toReal
hx_pos : 0 < μ.rnDeriv ν x
hx_lt_top : μ.rnDeriv ν x < ∞
⊢ log (μ.rnDeriv (ν.tilted f) x).toReal = -f x + log (∫ (z : α), rexp (f z) ∂ν) + llr μ ν x
Module: Mathlib.MeasureTheory.Function.LpSpace.CompleteOfCompleteLp

Goal state before:
pp: α : Type u_1
E : Type u_2
inst✝¹ : NormedAddCommGroup E
mα : MeasurableSpace α
μ : Measure α
inst✝ : Nontrivial ↥(Lp E 0 μ)
f : ↥(Lp E 0 μ)
hf : f ≠ 0
hfne : ¬↑↑f =ᵐ[μ] 0
h'p : 0 < ∞
⊢ MemLp (fun x ↦ 1) 0 μ

Tactic:
simpa using aestronglyMeasurable_const

Goal state after:
Module: Mathlib.InformationTheory.KullbackLeibler.Basic

Goal state before:
pp: case neg
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
c : ℝ≥0
hc : ¬c = 0
hc' : ↑c ≠ 0
hμ_smul : ∀ (μ : Measure α), μ = c⁻¹ • c • μ
hμν : ¬μ ≪ ν
h_contra : c • μ ≪ c • ν
⊢ c⁻¹ • c • μ ≪ c⁻¹ • c • ν

Tactic:
exact h_contra.smul _

Goal state after:
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.CondexpL2

Goal state before:
pp: α : Type u_1
𝕜 : Type u_7
inst✝ : RCLike 𝕜
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
f : ↥(Lp 𝕜 2 μ)
hs : MeasurableSet s
hμs : μ s ≠ ∞
h_eq_inner : ∫ (x : α) in s, ↑↑↑((condExpL2 𝕜 𝕜 hm) f) x ∂μ = ⟪indicatorConstLp 2 ⋯ hμs 1, ↑((condExpL2 𝕜 𝕜 hm) f)⟫
⊢ ∫ (x : α) in s, ↑↑↑((condExpL2 𝕜 𝕜 hm) f) x ∂μ = ⟪indicatorConstLp 2 ⋯ hμs 1, f⟫

Tactic:
rw [h_eq_inner, ← inner_condExpL2_left_eq_right, condExpL2_indicator_of_measurable hm hs hμs]

Goal state after:
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.AEMeasurable

Goal state before:
pp: α : Type u_1
F : Type u_2
p : ℝ≥0∞
inst✝² : NormedAddCommGroup F
m m0 : MeasurableSpace α
μ : Measure α
inst✝¹ : Fact (1 ≤ p)
inst✝ : NormedSpace ℝ F
hm : m ≤ m0
hp_ne_top : p ≠ ∞
P : ↥(Lp F p μ) → Prop
h_ind : ∀ (c : F) {s : Set α} (hs : MeasurableSet s) (hμs : μ s < ∞), P ↑(simpleFunc.indicatorConst p ⋯ ⋯ c)
h_add :
  ∀ ⦃f g : α → F⦄ (hf : MemLp f p μ) (hg : MemLp g p μ),
    StronglyMeasurable f →
      StronglyMeasurable g →
        Disjoint (Function.support f) (Function.support g) →
          P (MemLp.toLp f hf) → P (MemLp.toLp g hg) → P (MemLp.toLp f hf + MemLp.toLp g hg)
h_closed : IsClosed {f | P ↑f}
f✝ : ↥(Lp F p μ)
hf✝ : AEStronglyMeasurable (↑↑f✝) μ
f g : α → F
hf : MemLp f p μ
hg : MemLp g p μ
hfm : AEStronglyMeasurable f μ
hgm : AEStronglyMeasurable g μ
h_disj : Disjoint (Function.support f) (Function.support g)
hPf : P (MemLp.toLp f hf)
hPg : P (MemLp.toLp g hg)
s_f : Set α := Function.support (AEStronglyMeasurable.mk f hfm)
hs_f : MeasurableSet s_f
hs_f_eq : s_f =ᵐ[μ] Function.support f
s_g : Set α := Function.support (AEStronglyMeasurable.mk g hgm)
hs_g : MeasurableSet s_g
hs_g_eq : s_g =ᵐ[μ] Function.support g
this : Function.support f ∩ Function.support g = ∅
⊢ Function.support f ∩ Function.support g =ᵐ[μ] ∅

Tactic:
rw [this]

Goal state after:
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.CondexpL2

Goal state before:
pp: α : Type u_1
E : Type u_2
𝕜 : Type u_7
inst✝³ : RCLike 𝕜
inst✝² : NormedAddCommGroup E
inst✝¹ : InnerProductSpace 𝕜 E
inst✝ : CompleteSpace E
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
f : ↥(Lp E 2 μ)
c : E
⊢ ↑↑↑((condExpL2 𝕜 𝕜 hm) (MemLp.toLp (fun a ↦ ⟪c, ↑↑f a⟫) ⋯)) =ᵐ[μ] fun a ↦ ⟪c, ↑↑↑((condExpL2 E 𝕜 hm) f) a⟫

Tactic:
by
  have h_mem_Lp : MemLp (fun a => ⟪c, (condExpL2 E 𝕜 hm f : α → E) a⟫) 2 μ := by
    refine MemLp.const_inner _ ?_; exact Lp.memLp _
  have h_eq : h_mem_Lp.toLp _ =ᵐ[μ] fun a => ⟪c, (condExpL2 E 𝕜 hm f : α → E) a⟫ :=
    h_mem_Lp.coeFn_toLp
  refine EventuallyEq.trans ?_ h_eq
  refine Lp.ae_eq_of_forall_setIntegral_eq' 𝕜 hm _ _ two_ne_zero ENNReal.coe_ne_top
    (fun s _ hμs => integrableOn_condExpL2_of_measure_ne_top hm hμs.ne _) ?_ ?_ ?_ ?_
  · intro s _ hμs
    rw [IntegrableOn, integrable_congr (ae_restrict_of_ae h_eq)]
    exact (integrableOn_condExpL2_of_measure_ne_top hm hμs.ne _).const_inner _
  · intro s hs hμs
    rw [integral_condExpL2_eq_of_fin_meas_real _ hs hμs.ne,
      integral_congr_ae (ae_restrict_of_ae h_eq), ←
      L2.inner_indicatorConstLp_eq_setIntegral_inner 𝕜 (↑(condExpL2 E 𝕜 hm f)) (hm s hs) c hμs.ne,
      ← inner_condExpL2_left_eq_right, condExpL2_indicator_of_measurable _ hs,
      L2.inner_indicatorConstLp_eq_setIntegral_inner 𝕜 f (hm s hs) c hμs.ne,
      setIntegral_congr_ae (hm s hs)
        ((MemLp.coeFn_toLp ((Lp.memLp f).const_inner c)).mono fun x hx _ => hx)]
  · exact lpMeas.aestronglyMeasurable _
  · refine AEStronglyMeasurable.congr ?_ h_eq.symm
    exact (lpMeas.aestronglyMeasurable _).const_inner

Goal state after:
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.AEMeasurable

Goal state before:
pp: case refine_2
α : Type u_1
F : Type u_2
p : ℝ≥0∞
inst✝² : NormedAddCommGroup F
m m0 : MeasurableSpace α
μ : Measure α
inst✝¹ : Fact (1 ≤ p)
inst✝ : NormedSpace ℝ F
hm : m ≤ m0
hp_ne_top : p ≠ ∞
P : (α → F) → Prop
h_ind : ∀ (c : F) ⦃s : Set α⦄, MeasurableSet s → μ s < ∞ → P (s.indicator fun x ↦ c)
h_closed : IsClosed {f | P ↑↑↑f}
h_ae : ∀ ⦃f g : α → F⦄, f =ᵐ[μ] g → MemLp f p μ → P f → P g
f✝ : α → F
hf : MemLp f✝ p μ
hfm✝ : AEStronglyMeasurable f✝ μ
f_Lp : ↥(Lp F p μ) := toLp f✝ hf
hfm_Lp : AEStronglyMeasurable (↑↑f_Lp) μ
f g : α → F
h_add : P (f + g)
hf_mem : MemLp f p μ
hg_mem : MemLp g p μ
hfm : StronglyMeasurable f
hgm : StronglyMeasurable g
h_disj : Disjoint (Function.support f) (Function.support g)
hfP : P ↑↑(toLp f hf_mem)
hgP : P ↑↑(toLp g hg_mem)
hfP' : P f
hgP' : P g
⊢ P ↑↑(toLp f hf_mem + toLp g hg_mem)

Tactic:
refine h_ae ?_ (hf_mem.add hg_mem) h_add

Goal state after:
case refine_2
α : Type u_1
F : Type u_2
p : ℝ≥0∞
inst✝² : NormedAddCommGroup F
m m0 : MeasurableSpace α
μ : Measure α
inst✝¹ : Fact (1 ≤ p)
inst✝ : NormedSpace ℝ F
hm : m ≤ m0
hp_ne_top : p ≠ ∞
P : (α → F) → Prop
h_ind : ∀ (c : F) ⦃s : Set α⦄, MeasurableSet s → μ s < ∞ → P (s.indicator fun x ↦ c)
h_closed : IsClosed {f | P ↑↑↑f}
h_ae : ∀ ⦃f g : α → F⦄, f =ᵐ[μ] g → MemLp f p μ → P f → P g
f✝ : α → F
hf : MemLp f✝ p μ
hfm✝ : AEStronglyMeasurable f✝ μ
f_Lp : ↥(Lp F p μ) := toLp f✝ hf
hfm_Lp : AEStronglyMeasurable (↑↑f_Lp) μ
f g : α → F
h_add : P (f + g)
hf_mem : MemLp f p μ
hg_mem : MemLp g p μ
hfm : StronglyMeasurable f
hgm : StronglyMeasurable g
h_disj : Disjoint (Function.support f) (Function.support g)
hfP : P ↑↑(toLp f hf_mem)
hgP : P ↑↑(toLp g hg_mem)
hfP' : P f
hgP' : P g
⊢ f + g =ᵐ[μ] ↑↑(toLp f hf_mem + toLp g hg_mem)