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

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ ν : Measure α
κ η : Kernel α β
inst✝¹ : SFinite μ
inst✝ : IsSFiniteKernel κ
h_zero : ∀ (a : α), NeZero (κ a)
h : μ ⊗ₘ κ ≪ ν ⊗ₘ η
s : Set α
hs : MeasurableSet s
hs0 : ν s = 0
h1 : (ν ⊗ₘ η) (s ×ˢ univ) = 0
h2 : (fun a ↦ (κ a) univ) =ᵐ[μ.restrict s] 0
hμs : ¬μ s = 0
this : (ae (μ.restrict s)).NeBot
a : α
ha : (κ a) univ = 0
⊢ False

Tactic:
refine absurd ha ?_

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ ν : Measure α
κ η : Kernel α β
inst✝¹ : SFinite μ
inst✝ : IsSFiniteKernel κ
h_zero : ∀ (a : α), NeZero (κ a)
h : μ ⊗ₘ κ ≪ ν ⊗ₘ η
s : Set α
hs : MeasurableSet s
hs0 : ν s = 0
h1 : (ν ⊗ₘ η) (s ×ˢ univ) = 0
h2 : (fun a ↦ (κ a) univ) =ᵐ[μ.restrict s] 0
hμs : ¬μ s = 0
this : (ae (μ.restrict s)).NeBot
a : α
ha : (κ a) univ = 0
⊢ ¬(κ a) univ = 0
Module: Mathlib.Probability.Kernel.Composition.MapComap

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
inst✝ : Nonempty γ
κ : Kernel α β
inhabited_h : Inhabited γ
h : IsSFiniteKernel (prodMkRight γ κ)
⊢ IsSFiniteKernel κ

Tactic:
← sectL_prodMkRight γ κ default

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝ : Nonempty γ
κ : Kernel α β
inhabited_h : Inhabited γ
h : IsSFiniteKernel (prodMkRight γ κ)
⊢ IsSFiniteKernel ((prodMkRight γ κ).sectL default)
Module: Mathlib.Probability.Kernel.Composition.MeasureCompProd

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ ν : Measure α
κ η : Kernel α β
ξ : Measure α
inst✝³ : SFinite μ
inst✝² : SFinite ν
inst✝¹ : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
h : μ ⊗ₘ κ ⟂ₘ ν ⊗ₘ η
hμ : ξ ≪ μ
hν : ξ ≪ ν
hs : MeasurableSet h.nullSet
hμ_zero : ∫⁻ (a : α), (κ a) (Prod.mk a ⁻¹' h.nullSet) ∂μ = 0
hν_zero : ∫⁻ (a : α), (η a) (Prod.mk a ⁻¹' h.nullSetᶜ) ∂ν = 0
⊢ AEMeasurable (fun a ↦ (κ a) (Prod.mk a ⁻¹' h.nullSet)) μ

Tactic:
exact (Kernel.measurable_kernel_prodMk_left hs).aemeasurable

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

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ ν : Measure α
κ η : Kernel α β
ξ : Measure α
inst✝³ : SFinite μ
inst✝² : SFinite ν
inst✝¹ : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
h : μ ⊗ₘ κ ⟂ₘ ν ⊗ₘ η
hμ : ξ ≪ μ
hν : ξ ≪ ν
hs : MeasurableSet h.nullSet
hμ_zero : (μ ⊗ₘ κ) h.nullSet = 0
hν_zero : (ν ⊗ₘ η) h.nullSetᶜ = 0
⊢ MeasurableSet h.nullSet

Tactic:
· exact hs

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

Goal state before:
pp: case refine_2.refine_3
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ ν : Measure α
κ η : Kernel α β
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
h : ∀ (ξ : Measure α), SFinite ξ → ξ ≪ μ → ξ ≪ ν → ξ ⊗ₘ κ ⟂ₘ ξ ⊗ₘ η
⊢ ν.withDensity (μ.rnDeriv ν) ≪ ν

Tactic:
· exact withDensity_absolutelyContinuous ν (μ.rnDeriv ν)

Goal state after:
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
⊢ ∫⁻ (a : β × γ), ‖f a‖ₑ ∂(κ ⊗ₖ η) a < ∞ ↔
    (∀ᵐ (x : β) ∂κ a, ∫⁻ (a : γ), ‖f (x, a)‖ₑ ∂η (a, x) < ∞) ∧
      ∫⁻ (a_1 : β), ‖∫ (y : γ), ‖f (a_1, y)‖ ∂η (a, a_1)‖ₑ ∂κ a < ∞

Tactic:
lintegral_compProd _ _ _ h1f.enorm

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
⊢ ∫⁻ (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), ‖∫ (y : γ), ‖f (a_1, y)‖ ∂η (a, a_1)‖ₑ ∂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 : AEMeasurable f ((κ ⊗ₖ η) a)
A : ∫⁻ (z : β × γ), f z ∂(κ ⊗ₖ η) a = ∫⁻ (z : β × γ), AEMeasurable.mk f hf z ∂(κ ⊗ₖ η) a
B : ∫⁻ (x : β), ∫⁻ (y : γ), f (x, y) ∂η (a, x) ∂κ a = ∫⁻ (x : β), ∫⁻ (y : γ), AEMeasurable.mk f hf (x, y) ∂η (a, x) ∂κ a
⊢ ∫⁻ (z : β × γ), AEMeasurable.mk f hf z ∂(κ ⊗ₖ η) a = ∫⁻ (x : β), ∫⁻ (y : γ), f (x, y) ∂η (a, x) ∂κ a

Tactic:
B,

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 : AEMeasurable f ((κ ⊗ₖ η) a)
A : ∫⁻ (z : β × γ), f z ∂(κ ⊗ₖ η) a = ∫⁻ (z : β × γ), AEMeasurable.mk f hf z ∂(κ ⊗ₖ η) a
B : ∫⁻ (x : β), ∫⁻ (y : γ), f (x, y) ∂η (a, x) ∂κ a = ∫⁻ (x : β), ∫⁻ (y : γ), AEMeasurable.mk f hf (x, y) ∂η (a, x) ∂κ a
⊢ ∫⁻ (z : β × γ), AEMeasurable.mk f hf z ∂(κ ⊗ₖ η) a =
    ∫⁻ (x : β), ∫⁻ (y : γ), AEMeasurable.mk f hf (x, y) ∂η (a, x) ∂κ a
Module: Mathlib.Probability.Kernel.Composition.RadonNikodym

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
μ : Measure α
κ η : Kernel α β
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : IsFiniteKernel η
h_ac : μ ⊗ₘ κ ≪ μ ⊗ₘ η
ν : Measure α
inst✝ : IsFiniteMeasure ν
p : α × β
hp : (μ ⊗ₘ η).rnDeriv (ν ⊗ₘ η) p = μ.rnDeriv ν p.1
⊢ ((μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) * (μ ⊗ₘ η).rnDeriv (ν ⊗ₘ η)) p = μ.rnDeriv ν p.1 * (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) p

Tactic:
rw [Pi.mul_apply, hp, mul_comm]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.IntegralRNDeriv

Goal state before:
pp: 𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h_rnDeriv_eq : μ'.rnDeriv ν' =ᵐ[ν] μ.rnDeriv ν
⊢ (ν univ)⁻¹.toReal * ∫ (x : 𝓧), f (μ'.rnDeriv ν' x).toReal ∂ν =
    (ν.real univ)⁻¹ * ∫ (x : 𝓧), f (μ.rnDeriv ν x).toReal ∂ν

Tactic:
ENNReal.toReal_inv

Goal state after:
𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h_rnDeriv_eq : μ'.rnDeriv ν' =ᵐ[ν] μ.rnDeriv ν
⊢ (ν univ).toReal⁻¹ * ∫ (x : 𝓧), f (μ'.rnDeriv ν' x).toReal ∂ν =
    (ν.real univ)⁻¹ * ∫ (x : 𝓧), f (μ.rnDeriv ν x).toReal ∂ν
Module: Mathlib.MeasureTheory.Measure.Tilted

Goal state before:
pp: case pos.hs
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
g : α → ℝ≥0∞
s : Set α
hs : MeasurableSet s
hf : AEMeasurable f μ
⊢ MeasurableSet s

pp: case pos.h'f
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
g : α → ℝ≥0∞
s : Set α
hs : MeasurableSet s
hf : AEMeasurable f μ
⊢ ∀ᵐ (x : α) ∂μ.restrict s, ENNReal.ofReal (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) < ∞

Tactic:
· exact hs

Goal state after:
case pos.h'f
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
g : α → ℝ≥0∞
s : Set α
hs : MeasurableSet s
hf : AEMeasurable f μ
⊢ ∀ᵐ (x : α) ∂μ.restrict s, ENNReal.ofReal (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) < ∞
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : μ.HaveLebesgueDecomposition ν
hμν : μ ≪ ν
c : ℝ≥0∞
hc : c ≠ 0
hc_ne_top : c ≠ ∞
h : (c • μ).rnDeriv ν =ᵐ[ν] c • μ.rnDeriv ν
x : α
hx_eq : (c • μ).rnDeriv ν x = (c • μ.rnDeriv ν) x
hx_pos : 0 < μ.rnDeriv ν x
hx_ne_top : μ.rnDeriv ν x < ∞
⊢ log ((c • μ).rnDeriv ν x).toReal = log (μ.rnDeriv ν x).toReal + log c.toReal

Tactic:
rw [hx_eq]

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : μ.HaveLebesgueDecomposition ν
hμν : μ ≪ ν
c : ℝ≥0∞
hc : c ≠ 0
hc_ne_top : c ≠ ∞
h : (c • μ).rnDeriv ν =ᵐ[ν] c • μ.rnDeriv ν
x : α
hx_eq : (c • μ).rnDeriv ν x = (c • μ.rnDeriv ν) x
hx_pos : 0 < μ.rnDeriv ν x
hx_ne_top : μ.rnDeriv ν x < ∞
⊢ log ((c • μ.rnDeriv ν) x).toReal = log (μ.rnDeriv ν x).toReal + log c.toReal
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : μ.HaveLebesgueDecomposition ν
hμν : μ ≪ ν
c : ℝ≥0∞
hc : c ≠ 0
hc_ne_top : c ≠ ∞
h : μ.rnDeriv (c • ν) =ᵐ[ν] c⁻¹ • μ.rnDeriv ν
x : α
hx_eq : μ.rnDeriv (c • ν) x = (c⁻¹ • μ.rnDeriv ν) x
hx_pos : 0 < μ.rnDeriv ν x
hx_ne_top : μ.rnDeriv ν x < ∞
⊢ log (μ.rnDeriv (c • ν) x).toReal = log (μ.rnDeriv ν x).toReal - log c.toReal

Tactic:
rw [hx_eq]

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : μ.HaveLebesgueDecomposition ν
hμν : μ ≪ ν
c : ℝ≥0∞
hc : c ≠ 0
hc_ne_top : c ≠ ∞
h : μ.rnDeriv (c • ν) =ᵐ[ν] c⁻¹ • μ.rnDeriv ν
x : α
hx_eq : μ.rnDeriv (c • ν) x = (c⁻¹ • μ.rnDeriv ν) x
hx_pos : 0 < μ.rnDeriv ν x
hx_ne_top : μ.rnDeriv ν x < ∞
⊢ log ((c⁻¹ • μ.rnDeriv ν) x).toReal = log (μ.rnDeriv ν x).toReal - log c.toReal
Module: Mathlib.MeasureTheory.Measure.LogLikelihoodRatio

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : μ.HaveLebesgueDecomposition ν
hμν : μ ≪ ν
c : ℝ≥0
hc : c ≠ 0
⊢ llr (c • μ) (c • ν) =ᵐ[μ] llr μ ν

Tactic:
simp_rw [← Measure.coe_nnreal_smul]

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : μ.HaveLebesgueDecomposition ν
hμν : μ ≪ ν
c : ℝ≥0
hc : c ≠ 0
⊢ llr (↑c • μ) (↑c • ν) =ᵐ[μ] llr μ ν
Module: Mathlib.MeasureTheory.Measure.Tilted

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
inst✝ : SigmaFinite μ
hf : Integrable (fun x ↦ rexp (f x)) μ
h0 : NeZero μ
hf' : AEMeasurable f μ
x : α
hx : (μ.tilted f).rnDeriv μ x = ENNReal.ofReal (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ)
⊢ log (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ) = f x - log (∫ (x : α), rexp (f x) ∂μ)

Tactic:
log_div (exp_pos _).ne',

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
inst✝ : SigmaFinite μ
hf : Integrable (fun x ↦ rexp (f x)) μ
h0 : NeZero μ
hf' : AEMeasurable f μ
x : α
hx : (μ.tilted f).rnDeriv μ x = ENNReal.ofReal (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ)
⊢ log (rexp (f x)) - log (∫ (x : α), rexp (f x) ∂μ) = f x - log (∫ (x : α), rexp (f x) ∂μ)

α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ
inst✝ : SigmaFinite μ
hf : Integrable (fun x ↦ rexp (f x)) μ
h0 : NeZero μ
hf' : AEMeasurable f μ
x : α
hx : (μ.tilted f).rnDeriv μ x = ENNReal.ofReal (rexp (f x) / ∫ (x : α), rexp (f x) ∂μ)
⊢ ∫ (x : α), rexp (f x) ∂μ ≠ 0
Module: Mathlib.MeasureTheory.Measure.Decomposition.IntegralRNDeriv

Goal state before:
pp: 𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
𝓨 : Type u_2
m𝓨 : MeasurableSpace 𝓨
κ η : Kernel 𝓧 𝓨
f : ℝ → ℝ
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteMeasure ν
inst✝¹ : IsMarkovKernel κ
inst✝ : IsMarkovKernel η
hf : StronglyMeasurable f
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont_at : ContinuousWithinAt f (Ici 0) 0
h_int✝ :
  (∀ᵐ (x : 𝓧) ∂ν, Integrable (fun y ↦ f ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (x, y)).toReal) (η x)) ∧
    Integrable (fun x ↦ ∫ (y : 𝓨), ‖f ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (x, y)).toReal‖ ∂η x) ν
hκη : μ ⊗ₘ κ ≪ μ ⊗ₘ η
hf_cont : ContinuousOn f (Ici 0)
h_lt_top✝ : ∀ᵐ (a : 𝓧) ∂ν, ∀ᵐ (b : 𝓨) ∂η a, (μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b) < ∞
h_integrable :
  (∀ᵐ (x : 𝓧) ∂ν, Integrable (fun y ↦ ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (x, y)).toReal) (η x)) ∧
    Integrable (fun x ↦ ∫ (y : 𝓨), ‖((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (x, y)).toReal‖ ∂η x) ν
h_ae1 : ∀ᵐ (a : 𝓧) ∂ν, μ.rnDeriv ν a * ∫⁻ (b : 𝓨), (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) (a, b) ∂η a = μ.rnDeriv ν a
h_ae2 :
  ∀ᵐ (a : 𝓧) ∂ν, ∀ᵐ (b : 𝓨) ∂η a, μ.rnDeriv ν a * (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) (a, b) = (μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b)
a : 𝓧
h_eq_one : μ.rnDeriv ν a * ∫⁻ (b : 𝓨), (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) (a, b) ∂η a = μ.rnDeriv ν a
h_mul_eq : ∀ᵐ (b : 𝓨) ∂η a, μ.rnDeriv ν a * (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) (a, b) = (μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b)
h_lt_top : ∀ᵐ (b : 𝓨) ∂η a, (μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b) < ∞
h_int' : Integrable (fun y ↦ ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, y)).toReal) (η a)
h_int : Integrable (fun y ↦ f ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, y)).toReal) (η a)
⊢ f (μ.rnDeriv ν a).toReal ≤ ∫ (b : 𝓨), f ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b)).toReal ∂η a

Tactic:
calc f (μ.rnDeriv ν a).toReal
    = f (μ.rnDeriv ν a * ∫⁻ b, (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) (a, b) ∂(η a)).toReal := by simp [h_eq_one]
  _ = f (∫⁻ b, (μ.rnDeriv ν a) * (μ ⊗ₘ κ).rnDeriv (μ ⊗ₘ η) (a, b) ∂(η a)).toReal := by
    rw [lintegral_const_mul _ (by fun_prop)]
  _ = f (∫⁻ b, (μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b) ∂(η a)).toReal := by
    congr 2
    refine lintegral_congr_ae ?_
    filter_upwards [h_mul_eq] with b hb using hb
  _ = f (∫ b, ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b)).toReal ∂(η a)) := by
    rw [integral_toReal (by fun_prop) h_lt_top]
  _ ≤ ∫ b, f ((μ ⊗ₘ κ).rnDeriv (ν ⊗ₘ η) (a, b)).toReal ∂(η a) := by
    rw [← average_eq_integral, ← average_eq_integral]
    exact ConvexOn.map_average_le hf_cvx hf_cont isClosed_Ici (by simp) h_int' h_int

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

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hμν : μ ≪ ν
h_int : Integrable (llr μ ν) μ
⊢ ∫ (a : α), (μ.rnDeriv ν a).toReal * log (μ.rnDeriv ν a).toReal ∂ν + ν.real univ - μ.real univ =
    ∫ (x : α), llr μ ν x ∂μ + ν.real univ - μ.real univ

Tactic:
congr 2

Goal state after:
case e_a.e_a
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hμν : μ ≪ ν
h_int : Integrable (llr μ ν) μ
⊢ ∫ (a : α), (μ.rnDeriv ν a).toReal * log (μ.rnDeriv ν a).toReal ∂ν = ∫ (x : α), llr μ ν x ∂μ
Module: Mathlib.MeasureTheory.Function.LpSpace.CompleteOfCompleteLp

Goal state before:
pp: α : Type u_1
E : Type u_2
inst✝³ : NormedAddCommGroup E
mα : MeasurableSpace α
p : ℝ≥0∞
μ : Measure α
inst✝² : NormedSpace ℝ E
hp : Fact (1 ≤ p)
inst✝¹ : CompleteSpace ↥(Lp E p μ)
inst✝ : Nontrivial ↥(Lp E p μ)
this : Nontrivial ↥(Lp ℝ p μ)
⊢ ∃ f, f ≠ 0

Tactic:
exact exists_ne 0

Goal state after:
Module: Mathlib.MeasureTheory.Function.LpSpace.CompleteOfCompleteLp

Goal state before:
pp: α : Type u_1
E : Type u_2
inst✝³ : NormedAddCommGroup E
mα : MeasurableSpace α
p : ℝ≥0∞
μ : Measure α
inst✝² : NormedSpace ℝ E
hp : Fact (1 ≤ p)
inst✝¹ : CompleteSpace ↥(Lp E p μ)
inst✝ : Nontrivial ↥(Lp E p μ)
f : ↥(Lp ℝ p μ)
hf : f ≠ 0
m : E →L[ℝ] ↥(Lp E p μ) := (compLpL₂ p μ (lsmul ℝ ℝ).flip).flip f
u : ℕ → E
hu : CauchySeq u
g : ↥(Lp E p μ)
hg : Tendsto (⇑m ∘ u) atTop (𝓝 g)
f' : ℕ → α → E := fun n ↦ ↑↑((⇑m ∘ u) n)
ns : ℕ → ℕ
hns : StrictMono ns
nslim : ∀ᵐ (x : α) ∂μ, Tendsto (fun i ↦ f' (ns i) x) atTop (𝓝 (↑↑g x))
this : (ae (μ.restrict (Function.support ↑↑f))).NeBot
A : ∀ᵐ (x : α) ∂μ.restrict (Function.support ↑↑f), Tendsto (fun i ↦ f' (ns i) x) atTop (𝓝 (↑↑g x))
B : ∀ᵐ (x : α) ∂μ.restrict (Function.support ↑↑f), x ∈ Function.support ↑↑f
C : ∀ᵐ (x : α) ∂μ.restrict (Function.support ↑↑f), ∀ (n : ℕ), ↑↑(m (u n)) x = ↑↑f x • u n
x : α
hx : x ∈ Function.support ↑↑f
hmx : ∀ (n : ℕ), ↑↑(m (u n)) x = ↑↑f x • u n
xlim : Tendsto (fun i ↦ ↑↑f x • u (ns i)) atTop (𝓝 (↑↑g x))
n : ℕ
⊢ (u ∘ ns) n = (↑↑f x)⁻¹ • ↑↑f x • u (ns n)

Tactic:
rw [smul_smul, inv_mul_cancel₀, one_smul, Function.comp]

Goal state after:
α : Type u_1
E : Type u_2
inst✝³ : NormedAddCommGroup E
mα : MeasurableSpace α
p : ℝ≥0∞
μ : Measure α
inst✝² : NormedSpace ℝ E
hp : Fact (1 ≤ p)
inst✝¹ : CompleteSpace ↥(Lp E p μ)
inst✝ : Nontrivial ↥(Lp E p μ)
f : ↥(Lp ℝ p μ)
hf : f ≠ 0
m : E →L[ℝ] ↥(Lp E p μ) := (compLpL₂ p μ (lsmul ℝ ℝ).flip).flip f
u : ℕ → E
hu : CauchySeq u
g : ↥(Lp E p μ)
hg : Tendsto (⇑m ∘ u) atTop (𝓝 g)
f' : ℕ → α → E := fun n ↦ ↑↑((⇑m ∘ u) n)
ns : ℕ → ℕ
hns : StrictMono ns
nslim : ∀ᵐ (x : α) ∂μ, Tendsto (fun i ↦ f' (ns i) x) atTop (𝓝 (↑↑g x))
this : (ae (μ.restrict (Function.support ↑↑f))).NeBot
A : ∀ᵐ (x : α) ∂μ.restrict (Function.support ↑↑f), Tendsto (fun i ↦ f' (ns i) x) atTop (𝓝 (↑↑g x))
B : ∀ᵐ (x : α) ∂μ.restrict (Function.support ↑↑f), x ∈ Function.support ↑↑f
C : ∀ᵐ (x : α) ∂μ.restrict (Function.support ↑↑f), ∀ (n : ℕ), ↑↑(m (u n)) x = ↑↑f x • u n
x : α
hx : x ∈ Function.support ↑↑f
hmx : ∀ (n : ℕ), ↑↑(m (u n)) x = ↑↑f x • u n
xlim : Tendsto (fun i ↦ ↑↑f x • u (ns i)) atTop (𝓝 (↑↑g x))
n : ℕ
⊢ ↑↑f x ≠ 0
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.Unique

Goal state before:
pp: α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
f g : α → ℝ
hf : StronglyMeasurable f
hfi : IntegrableOn f s μ
hg : StronglyMeasurable g
hgi : IntegrableOn g s μ
hgf : ∀ (t : Set α), MeasurableSet t → μ t < ∞ → ∫ (x : α) in t, g x ∂μ = ∫ (x : α) in t, f x ∂μ
hs : MeasurableSet s
hμs : μ s ≠ ∞
h_meas_nonneg_g : MeasurableSet {x | 0 ≤ g x}
⊢ ∫ (x : α) in {x | 0 ≤ g x}, g x ∂μ.restrict s - ∫ (x : α) in {x | g x ≤ 0}, g x ∂μ.restrict s ≤
    ∫ (x : α) in {x | 0 ≤ f x}, f x ∂μ.restrict s - ∫ (x : α) in {x | f x ≤ 0}, f x ∂μ.restrict s

Tactic:
have h_meas_nonneg_f : MeasurableSet {x | 0 ≤ f x} :=
    stronglyMeasurable_const.measurableSet_le hf

Goal state after:
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
hm : m ≤ m0
f g : α → ℝ
hf : StronglyMeasurable f
hfi : IntegrableOn f s μ
hg : StronglyMeasurable g
hgi : IntegrableOn g s μ
hgf : ∀ (t : Set α), MeasurableSet t → μ t < ∞ → ∫ (x : α) in t, g x ∂μ = ∫ (x : α) in t, f x ∂μ
hs : MeasurableSet s
hμs : μ s ≠ ∞
h_meas_nonneg_g : MeasurableSet {x | 0 ≤ g x}
h_meas_nonneg_f : MeasurableSet {x | 0 ≤ f x}
⊢ ∫ (x : α) in {x | 0 ≤ g x}, g x ∂μ.restrict s - ∫ (x : α) in {x | g x ≤ 0}, g x ∂μ.restrict s ≤
    ∫ (x : α) in {x | 0 ≤ f x}, f x ∂μ.restrict s - ∫ (x : α) in {x | f x ≤ 0}, f x ∂μ.restrict s
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.CondexpL1

Goal state before:
pp: α : Type u_1
G : Type u_4
inst✝² : NormedAddCommGroup G
m m0 : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedSpace ℝ G
hm : m ≤ m0
inst✝ : SigmaFinite (μ.trim hm)
x : G
⊢ ↑↑(condExpIndSMul hm ⋯ ⋯ x) =ᵐ[μ] ↑↑(0 x)

Tactic:
condExpIndSMul_empty,

Goal state after:
α : Type u_1
G : Type u_4
inst✝² : NormedAddCommGroup G
m m0 : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedSpace ℝ G
hm : m ≤ m0
inst✝ : SigmaFinite (μ.trim hm)
x : G
⊢ ↑↑0 =ᵐ[μ] ↑↑(0 x)
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.CondexpL1

Goal state before:
pp: α : Type u_1
G : Type u_4
inst✝² : NormedAddCommGroup G
m m0 : MeasurableSpace α
μ : Measure α
s t : Set α
inst✝¹ : NormedSpace ℝ G
hm : m ≤ m0
inst✝ : SigmaFinite (μ.trim hm)
hs : MeasurableSet s
ht : MeasurableSet t
hμs : μ s ≠ ∞
hμt : μ t ≠ ∞
hst : Disjoint s t
x : G
⊢ (condExpInd G hm μ (s ∪ t)) x = (⇑(condExpInd G hm μ s) + ⇑(condExpInd G hm μ t)) x

Tactic:
exact condExpInd_disjoint_union_apply hs ht hμs hμt hst x

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

Goal state before:
pp: α : Type u_1
G : Type u_5
inst✝¹ : NormedAddCommGroup G
m m0 : MeasurableSpace α
μ : Measure α
s : Set α
inst✝ : NormedSpace ℝ G
hm : m ≤ m0
hs : MeasurableSet s
hμs : μ s ≠ ∞
x : G
h : AEStronglyMeasurable (↑↑↑((condExpL2 ℝ ℝ hm) (indicatorConstLp 2 hs hμs 1))) μ
⊢ AEStronglyMeasurable (↑↑((compLpL 2 μ (toSpanSingleton ℝ x)) ↑((condExpL2 ℝ ℝ hm) (indicatorConstLp 2 hs hμs 1)))) μ

Tactic:
exact ((toSpanSingleton ℝ x).continuous.comp_aestronglyMeasurable h).congr
    (coeFn_compLpL _ _).symm

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

Goal state before:
pp: α : Type u_1
E : Type u_3
m₀ : MeasurableSpace α
μ : Measure α
f g : α → E
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : CompleteSpace E
hf : Integrable f μ
hg : Integrable g μ
m : MeasurableSpace α
⊢ μ[f - g | m] =ᵐ[μ] μ[f | m] - μ[g | m]

Tactic:
sub_eq_add_neg

Goal state after:
α : Type u_1
E : Type u_3
m₀ : MeasurableSpace α
μ : Measure α
f g : α → E
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : CompleteSpace E
hf : Integrable f μ
hg : Integrable g μ
m : MeasurableSpace α
⊢ μ[f + -g | m] =ᵐ[μ] μ[f | m] + -μ[g | m]
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.CondexpL1

Goal state before:
pp: case refine_3.refine_2
α : Type u_1
F' : Type u_3
inst✝³ : NormedAddCommGroup F'
inst✝² : NormedSpace ℝ F'
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
inst✝¹ : SigmaFinite (μ.trim hm)
inst✝ : CompleteSpace F'
f : ↥(lpMeas F' ℝ m 1 μ)
g : ↥(Lp F' 1 (μ.trim hm)) := (lpMeasToLpTrimLie F' ℝ 1 μ hm) f
hfg : f = (lpMeasToLpTrimLie F' ℝ 1 μ hm).symm g
⊢ Continuous fun f ↦ ↑((lpMeasToLpTrimLie F' ℝ 1 μ hm).symm f)

Tactic:
refine continuous_induced_dom.comp ?_

Goal state after:
case refine_3.refine_2
α : Type u_1
F' : Type u_3
inst✝³ : NormedAddCommGroup F'
inst✝² : NormedSpace ℝ F'
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
inst✝¹ : SigmaFinite (μ.trim hm)
inst✝ : CompleteSpace F'
f : ↥(lpMeas F' ℝ m 1 μ)
g : ↥(Lp F' 1 (μ.trim hm)) := (lpMeasToLpTrimLie F' ℝ 1 μ hm) f
hfg : f = (lpMeasToLpTrimLie F' ℝ 1 μ hm).symm g
⊢ Continuous ⇑(lpMeasToLpTrimLie F' ℝ 1 μ hm).symm
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.LebesgueBochner

Goal state before:
pp: case pos
𝓧 : Type u_1
m m𝓧 : MeasurableSpace 𝓧
μ : Measure 𝓧
f : 𝓧 → ℝ
hf : Integrable f μ
h'f : 0 ≤ᵐ[μ] f
hm : m ≤ m𝓧
hμ : SigmaFinite (μ.trim hm)
A : μ[fun x ↦ (ENNReal.ofReal (f x)).toReal | m] =ᵐ[μ] μ[f | m]
B : 0 ≤ᵐ[μ] μ[f | m]
g : 𝓧 → ℝ≥0∞ := fun x ↦ ENNReal.ofReal (f x)
⊢ μ⁻[fun x ↦ ENNReal.ofReal (f x) | m] =ᵐ[μ] fun x ↦ ENNReal.ofReal (μ[f | m] x)

Tactic:
have I : ∫⁻ x, g x ∂μ ≠ ∞ := by
    have : ∫⁻ x, g x ∂μ = ∫⁻ x, ‖f x‖ₑ ∂μ := by
      apply lintegral_congr_ae
      filter_upwards [h'f] with x hx using by simp [g, Real.enorm_eq_ofReal hx]
    rw [this]
    exact hf.2.ne

Goal state after:
case pos
𝓧 : Type u_1
m m𝓧 : MeasurableSpace 𝓧
μ : Measure 𝓧
f : 𝓧 → ℝ
hf : Integrable f μ
h'f : 0 ≤ᵐ[μ] f
hm : m ≤ m𝓧
hμ : SigmaFinite (μ.trim hm)
A : μ[fun x ↦ (ENNReal.ofReal (f x)).toReal | m] =ᵐ[μ] μ[f | m]
B : 0 ≤ᵐ[μ] μ[f | m]
g : 𝓧 → ℝ≥0∞ := fun x ↦ ENNReal.ofReal (f x)
I : ∫⁻ (x : 𝓧), g x ∂μ ≠ ∞
⊢ μ⁻[fun x ↦ ENNReal.ofReal (f x) | m] =ᵐ[μ] fun x ↦ ENNReal.ofReal (μ[f | m] x)