mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Probability.Distributions.Fernique

Goal state before:
pp: case neg
E : Type u_1
inst✝⁵ : SeminormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : SecondCountableTopology E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : IsFiniteMeasure μ
h_rot : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ.prod μ) = μ.prod μ
hμ_zero : ¬μ = 0
μ' : Measure E := μ[|Set.univ]
⊢ ∃ C, 0 < C ∧ Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ

Tactic:
have hμ'_eq : μ' = (μ .univ)⁻¹ • μ := by simp [μ', cond]

Goal state after:
case neg
E : Type u_1
inst✝⁵ : SeminormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : SecondCountableTopology E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : IsFiniteMeasure μ
h_rot : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ.prod μ) = μ.prod μ
hμ_zero : ¬μ = 0
μ' : Measure E := μ[|Set.univ]
hμ'_eq : μ' = (μ Set.univ)⁻¹ • μ
⊢ ∃ C, 0 < C ∧ Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ
Module: Mathlib.Probability.Distributions.Gaussian.IsGaussianProcess.Independence

Goal state before:
pp: T : Type u_1
Ω : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
S : Type u_4
X : S → Ω → ℝ
Y : T → Ω → ℝ
hXY : IsGaussianProcess (Sum.elim X Y) P
mX : ∀ (s : S), AEMeasurable (X s) P
mY : ∀ (t : T), AEMeasurable (Y t) P
h : ∀ (s : S) (t : T), cov[X s, Y t; P] = 0
x✝³ : S
x✝² : T
x✝¹ x✝ : ℝ
⊢ cov[fun ω ↦ ⟪x✝¹, X x✝³ ω⟫, fun ω ↦ ⟪x✝, Y x✝² ω⟫; P] = 0

Tactic:
by
    simp [covariance_mul_const_left, covariance_mul_const_right, h]

Goal state after:
Module: Mathlib.Probability.Distributions.Fernique

Goal state before:
pp: E : Type u_1
inst✝⁵ : SeminormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : SecondCountableTopology E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : IsFiniteMeasure μ
h_rot : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ.prod μ) = μ.prod μ
hμ_zero : ¬μ = 0
μ' : Measure E := μ[|Set.univ]
hμ'_eq : μ' = (μ Set.univ)⁻¹ • μ
hμ' : IsProbabilityMeasure μ'
⊢ ((μ Set.univ)⁻¹ * (μ Set.univ)⁻¹) • Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ.prod μ) =
    ((μ Set.univ)⁻¹ * (μ Set.univ)⁻¹) • μ.prod μ

Tactic:
rw [h_rot]

Goal state after:
Module: Mathlib.Probability.Distributions.Fernique

Goal state before:
pp: case neg
E : Type u_1
inst✝⁵ : SeminormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : SecondCountableTopology E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : IsFiniteMeasure μ
h_rot✝ : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ.prod μ) = μ.prod μ
hμ_zero : ¬μ = 0
μ' : Measure E := μ[|Set.univ]
hμ'_eq : μ' = (μ Set.univ)⁻¹ • μ
hμ' : IsProbabilityMeasure μ'
h_rot : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ'.prod μ') = μ'.prod μ'
C : ℝ
hC_pos : 0 < C
hC : Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ'
⊢ Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ

Tactic:
hμ'_eq,

Goal state after:
case neg
E : Type u_1
inst✝⁵ : SeminormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : SecondCountableTopology E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : IsFiniteMeasure μ
h_rot✝ : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ.prod μ) = μ.prod μ
hμ_zero : ¬μ = 0
μ' : Measure E := μ[|Set.univ]
hμ'_eq : μ' = (μ Set.univ)⁻¹ • μ
hμ' : IsProbabilityMeasure μ'
h_rot : Measure.map (⇑(ContinuousLinearMap.rotation (-(π / 4)))) (μ'.prod μ') = μ'.prod μ'
C : ℝ
hC_pos : 0 < C
hC : Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) ((μ Set.univ)⁻¹ • μ)
⊢ Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ
Module: Mathlib.Probability.BrownianMotion.Basic

Goal state before:
pp: Ω : Type u_1
mΩ : MeasurableSpace Ω
X : ℝ≥0 → Ω → ℝ
P : Measure Ω
h1 : IsGaussianProcess X P
h2 : ∀ (t : ℝ≥0), ∫ (x : Ω), X t x ∂P = 0
h3 : ∀ (s t : ℝ≥0), s ≤ t → cov[X s, X t; P] = ↑s
I : Finset ℝ≥0
⊢ Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P = projectiveFamily I

Tactic:
apply (MeasurableEquiv.toLp 2 (_ → ℝ)).map_measurableEquiv_injective

Goal state after:
Ω : Type u_1
mΩ : MeasurableSpace Ω
X : ℝ≥0 → Ω → ℝ
P : Measure Ω
h1 : IsGaussianProcess X P
h2 : ∀ (t : ℝ≥0), ∫ (x : Ω), X t x ∂P = 0
h3 : ∀ (s t : ℝ≥0), s ≤ t → cov[X s, X t; P] = ↑s
I : Finset ℝ≥0
⊢ Measure.map (⇑(MeasurableEquiv.toLp 2 (↥I → ℝ))) (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P) =
    Measure.map (⇑(MeasurableEquiv.toLp 2 (↥I → ℝ))) (projectiveFamily I)
Module: Mathlib.Probability.Kernel.Disintegration.CDFToKernel

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α (β × ℝ)
ν : Kernel α β
f : α × β → ℚ → ℝ
hf : IsRatCondKernelCDF f κ ν
a : α
q : ℚ
⊢ (fun b ↦ ↑(stieltjesOfMeasurableRat f ⋯ (a, b)) ↑q) =ᵐ[ν a] fun b ↦ f (a, b) q

Tactic:
filter_upwards [hf.isRatStieltjesPoint_ae a] with a ha
  rw [stieltjesOfMeasurableRat_eq, toRatCDF_of_isRatStieltjesPoint ha]

Goal state after:
Module: Mathlib.Probability.Kernel.Disintegration.MeasurableStieltjes

Goal state before:
pp: α : Type u_1
f : α → ℚ → ℝ
inst✝ : MeasurableSpace α
hf : Measurable f
a : α
⊢ stieltjesOfMeasurableRat (fun p ↦ f p.2) ⋯ ((), a) = stieltjesOfMeasurableRat f hf a

Tactic:
by
  simp_rw [stieltjesOfMeasurableRat, IsMeasurableRatCDF.stieltjesFunction,
    ← IsMeasurableRatCDF.stieltjesFunctionAux_unit_prod a]
  congr 1 with x
  congr 1 with p : 1
  cases p with
  | mk _ b => rw [← toRatCDF_unit_prod b]

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

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
μ : Measure α
ν : Measure β
inst✝¹ : SFinite ν
κ : Kernel β γ
inst✝ : IsSFiniteKernel κ
s : Set (α × γ)
hs : MeasurableSet s
⊢ (μ.prod (⇑κ ∘ₘ ν)) s = (⇑(Kernel.id ∥ₖ κ) ∘ₘ μ.prod ν) s

Tactic:
rw [Measure.prod_apply hs, Measure.bind_apply hs (Kernel.aemeasurable _)]

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
μ : Measure α
ν : Measure β
inst✝¹ : SFinite ν
κ : Kernel β γ
inst✝ : IsSFiniteKernel κ
s : Set (α × γ)
hs : MeasurableSet s
⊢ ∫⁻ (x : α), (⇑κ ∘ₘ ν) (Prod.mk x ⁻¹' s) ∂μ = ∫⁻ (a : α × β), ((Kernel.id ∥ₖ κ) a) s ∂μ.prod ν
Module: Mathlib.Probability.Kernel.Disintegration.Density

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✝ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
n : ℕ
a : α
s : Set β
hs : MeasurableSet s
⊢ Measurable fun x ↦ κ.densityProcess ν n a x s

Tactic:
by
  refine @Measurable.ennreal_toReal _ (countableFiltration γ n) _ ?_
  -- The exact also works without the `( :)`, but is a bit slow.
  exact ((measurable_densityProcess_countableFiltration_aux κ ν n hs).comp measurable_prodMk_left :)

Goal state after:
Module: Mathlib.Probability.Kernel.Disintegration.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
Ω : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mΩ : MeasurableSpace Ω
κ✝ : Kernel α (β × Ω)
κCond✝ : Kernel (α × β) Ω
inst✝³ : Countable α
κCond : α → Kernel β Ω
inst✝² : ∀ (a : α), IsMarkovKernel (κCond a)
h_atom : ∀ (x y : α), x ∈ measurableAtom y → κCond x = κCond y
κ : Kernel α (β × Ω)
inst✝¹ : IsSFiniteKernel κ
inst✝ : ∀ (a : α), (κ a).IsCondKernel (κCond a)
a : α
s : Set (β × Ω)
hs : MeasurableSet s
⊢ ((κ.fst ⊗ₖ condKernelCountable κCond h_atom) a) s = ((κ a).fst ⊗ₘ κCond a) s

Tactic:
compProd_apply hs,

Goal state after:
α : Type u_1
β : Type u_2
Ω : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mΩ : MeasurableSpace Ω
κ✝ : Kernel α (β × Ω)
κCond✝ : Kernel (α × β) Ω
inst✝³ : Countable α
κCond : α → Kernel β Ω
inst✝² : ∀ (a : α), IsMarkovKernel (κCond a)
h_atom : ∀ (x y : α), x ∈ measurableAtom y → κCond x = κCond y
κ : Kernel α (β × Ω)
inst✝¹ : IsSFiniteKernel κ
inst✝ : ∀ (a : α), (κ a).IsCondKernel (κCond a)
a : α
s : Set (β × Ω)
hs : MeasurableSet s
⊢ ∫⁻ (b : β), ((condKernelCountable κCond h_atom) (a, b)) (Prod.mk b ⁻¹' s) ∂κ.fst a = ((κ a).fst ⊗ₘ κCond a) s
Module: Mathlib.Probability.Kernel.Disintegration.Density

Goal state before:
pp: case refine_2.refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
mγ : MeasurableSpace γ
inst✝¹ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
hκν : κ.fst ≤ ν
inst✝ : IsFiniteKernel ν
a : α
s : Set β
hs : MeasurableSet s
⊢ ∀ (ε : ℝ),
    0 < ε →
      ∃ C,
        ∀ (i : ℕ),
          eLpNorm ({x | C ≤ ‖κ.densityProcess ν i a x s‖₊}.indicator fun x ↦ κ.densityProcess ν i a x s) 1 (ν a) ≤
            ENNReal.ofReal ε

Tactic:
· refine fun ε _ ↦ ⟨2, fun n ↦ le_of_eq_of_le ?_ (?_ : 0 ≤ ENNReal.ofReal ε)⟩
      · suffices {x | 2 ≤ ‖densityProcess κ ν n a x s‖₊} = ∅ by simp [this]
        ext x
        simp only [mem_ofPred_eq, mem_empty_iff_false, iff_false, not_le]
        refine (?_ : _ ≤ (1 : ℝ≥0)).trans_lt one_lt_two
        rw [Real.nnnorm_of_nonneg (densityProcess_nonneg _ _ _ _ _ _)]
        exact mod_cast (densityProcess_le_one hκν _ _ _ _)
      · simp

Goal state after:
Module: Mathlib.Probability.Kernel.CondDistrib

Goal state before:
pp: α : Type u_1
β : Type u_2
Ω : Type u_3
inst✝⁴ : MeasurableSpace Ω
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
mα : MeasurableSpace α
μ : Measure α
inst✝¹ : IsFiniteMeasure μ
X : α → β
Y : α → Ω
mβ : MeasurableSpace β
hX : Measurable X
hY : Measurable Y
κ : Kernel β Ω
inst✝ : IsFiniteKernel κ
hκ : Measure.map (fun x ↦ (X x, Y x)) μ = Measure.map X μ ⊗ₘ κ
heq : Measure.map X μ = (Measure.map (fun x ↦ (X x, Y x)) μ).fst
⊢ (Measure.map (fun a ↦ (X a, Y a)) μ).fst = Measure.map X μ

Tactic:
exact heq.symm

Goal state after:
Module: Mathlib.Probability.Kernel.CondDistrib

Goal state before:
pp: α : Type u_1
β : Type u_2
Ω : Type u_3
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
mα : MeasurableSpace α
μ : Measure α
inst✝² : IsFiniteMeasure μ
Y : α → Ω
mβ : MeasurableSpace β
Ω' : Type u_5
mΩ' : MeasurableSpace Ω'
inst✝¹ : StandardBorelSpace Ω'
inst✝ : Nonempty Ω'
X : α → β
hY : AEMeasurable Y μ
f : Ω → Ω'
hf : Measurable f
hX : AEMeasurable X μ
⊢ Measure.map (fun x ↦ (X x, (f ∘ Y) x)) μ = Measure.map (Prod.map id f) (Measure.map (fun x ↦ (X x, Y x)) μ)

Tactic:
by
    rw [AEMeasurable.map_map_of_aemeasurable (by fun_prop) (by fun_prop)]
    simp [Function.comp_def]

Goal state after:
Module: Mathlib.Probability.Kernel.IonescuTulcea.Maps

Goal state before:
pp: case pos
ι : Type u_1
inst✝⁴ : LinearOrder ι
inst✝³ : LocallyFiniteOrder ι
inst✝² : DecidableLE ι
X : ι → Type u_2
inst✝¹ : LocallyFiniteOrderBot ι
inst✝ : (i : ι) → MeasurableSpace (X i)
a b : ι
hab : a ≤ b
x : ↥(Iic b)
h : ↑x ≤ a
⊢ Measurable fun c ↦
    { toFun := fun x i ↦ if h : ↑i ≤ a then x.1 ⟨↑i, ⋯⟩ else x.2 ⟨↑i, ⋯⟩,
        invFun := fun x ↦ (fun i ↦ x ⟨↑i, ⋯⟩, fun i ↦ x ⟨↑i, ⋯⟩), left_inv := ⋯, right_inv := ⋯ }
      c x

Tactic:
simpa [h] using measurable_fst.eval

Goal state after:
Module: Mathlib.Probability.Kernel.CondDistrib

Goal state before:
pp: case refine_1
α : Type u_1
β : Type u_2
Ω : Type u_3
inst✝³ : MeasurableSpace Ω
inst✝² : StandardBorelSpace Ω
inst✝¹ : Nonempty Ω
mα : MeasurableSpace α
μ : Measure α
inst✝ : IsFiniteMeasure μ
X : α → β
Y : α → Ω
mβ : MeasurableSpace β
s : Set Ω
hX : AEMeasurable X μ
hs : MeasurableSet s
⊢ AEMeasurable (fun a ↦ ((condDistrib Y X μ) (X a)) s) μ

pp: case refine_2
α : Type u_1
β : Type u_2
Ω : Type u_3
inst✝³ : MeasurableSpace Ω
inst✝² : StandardBorelSpace Ω
inst✝¹ : Nonempty Ω
mα : MeasurableSpace α
μ : Measure α
inst✝ : IsFiniteMeasure μ
X : α → β
Y : α → Ω
mβ : MeasurableSpace β
s : Set Ω
hX : AEMeasurable X μ
hs : MeasurableSet s
⊢ ∫⁻ (x : α), ((condDistrib Y X μ) (X x)) s ∂μ ≠ ∞

Tactic:
· exact Measurable.comp_aemeasurable (Kernel.measurable_coe _ hs) hX

Goal state after:
case refine_2
α : Type u_1
β : Type u_2
Ω : Type u_3
inst✝³ : MeasurableSpace Ω
inst✝² : StandardBorelSpace Ω
inst✝¹ : Nonempty Ω
mα : MeasurableSpace α
μ : Measure α
inst✝ : IsFiniteMeasure μ
X : α → β
Y : α → Ω
mβ : MeasurableSpace β
s : Set Ω
hX : AEMeasurable X μ
hs : MeasurableSet s
⊢ ∫⁻ (x : α), ((condDistrib Y X μ) (X x)) s ∂μ ≠ ∞
Module: Mathlib.Probability.Kernel.Disintegration.Density

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✝¹ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
hκν : κ.fst ≤ ν
inst✝ : IsFiniteKernel ν
a : α
s : Set β
hs : MeasurableSet s
A : Set γ
hA : MeasurableSet A
this : IsFiniteKernel κ
⊢ ENNReal.ofReal (∫ (x : γ) in A, κ.density ν a x s ∂ν a) = (κ a) (A ×ˢ s)

Tactic:
setIntegral_density hκν a hs hA,

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✝¹ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
hκν : κ.fst ≤ ν
inst✝ : IsFiniteKernel ν
a : α
s : Set β
hs : MeasurableSet s
A : Set γ
hA : MeasurableSet A
this : IsFiniteKernel κ
⊢ ENNReal.ofReal ((κ a).real (A ×ˢ s)) = (κ a) (A ×ˢ s)
Module: Mathlib.Probability.Kernel.Disintegration.Density

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✝¹ : CountablyGenerated γ
κ : Kernel α (γ × β)
ν : Kernel α γ
hκν : κ.fst ≤ ν
inst✝ : IsFiniteKernel ν
a : α
s : Set β
hs : MeasurableSet s
⊢ ∫⁻ (x : γ) in univ, ENNReal.ofReal (κ.density ν a x s) ∂ν a = (κ a) (univ ×ˢ s)

Tactic:
exact setLIntegral_density hκν a hs MeasurableSet.univ

Goal state after:
Module: Mathlib.Probability.Kernel.WithDensity

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
⊢ κ.withDensity 1 = κ

Tactic:
by
  ext; rw [Kernel.withDensity_apply _ measurable_const]; simp

Goal state after:
Module: Mathlib.Probability.Kernel.WithDensity

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
⊢ κ.withDensity 0 = 0

Tactic:
by
  ext; rw [Kernel.withDensity_apply _ measurable_const]; simp

Goal state after:
Module: Mathlib.Probability.Kernel.WithDensity

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
f : α → β → ℝ≥0∞
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
hf : Measurable (Function.uncurry f)
a : α
g : β → ℝ≥0∞
hg : Measurable g
⊢ ∫⁻ (b : β), g b ∂(κ a).withDensity (f a) = ∫⁻ (b : β), f a b * g b ∂κ a

Tactic:
lintegral_withDensity_eq_lintegral_mul _ (Measurable.of_uncurry_left hf) hg

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
f : α → β → ℝ≥0∞
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
hf : Measurable (Function.uncurry f)
a : α
g : β → ℝ≥0∞
hg : Measurable g
⊢ ∫⁻ (a_1 : β), (f a * g) a_1 ∂κ a = ∫⁻ (b : β), f a b * g b ∂κ a
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case inl.e_a
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure (X n)
hμ : ∀ (n : ℕ), IsProbabilityMeasure (μ n)
a b : ℕ
hab : a ≤ b
s : (i : ↥(Iic b)) → Set (X ↑i)
ms : ∀ (i : ↥(Iic b)), MeasurableSet (s i)
x : ℕ
hx : x ∈ Ioc a b
⊢ Function.extend Subtype.val (fun i ↦ (μ ↑i) (s i)) 1 x =
    Function.extend Subtype.val (fun i ↦ (μ ↑i) (restrict₂ ⋯ s i)) 1 x

Tactic:
· rw [Function.extend_val_apply hx, Function.extend_val_apply (Ioc_subset_Iic_self hx),
        restrict₂]

Goal state after:
Module: Mathlib.Probability.Kernel.IonescuTulcea.Traj

Goal state before:
pp: X : ℕ → Type u_1
inst✝¹ : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
f : ℕ → ((n : ℕ) → X n) → ℝ≥0∞
a : ℕ → ℕ
hcte : ∀ (n : ℕ), DependsOn (f n) ↑(Iic (a n))
mf : ∀ (n : ℕ), Measurable (f n)
bound : ℝ≥0∞
fin_bound : bound ≠ ∞
le_bound : ∀ (n : ℕ) (x : (n : ℕ) → X n), f n x ≤ bound
k : ℕ
anti : ∀ (x : (n : ℕ) → X n), Antitone fun n ↦ lmarginalPartialTraj κ (k + 1) (a n) (f n) x
l : ((n : ℕ) → X n) → ℝ≥0∞
htendsto : ∀ (x : (n : ℕ) → X n), Tendsto (fun n ↦ lmarginalPartialTraj κ (k + 1) (a n) (f n) x) atTop (𝓝 (l x))
ε : ℝ≥0∞
y : (i : ↥(Iic k)) → X ↑i
hpos : ∀ (x : (i : ℕ) → X i) (n : ℕ), ε ≤ lmarginalPartialTraj κ k (a n) (f n) (updateFinset x (Iic k) y)
x✝ : ∀ (n : ℕ), Nonempty (X n)
F : ℕ → ((n : ℕ) → X n) → ℝ≥0∞ := fun n ↦ lmarginalPartialTraj κ (k + 1) (a n) (f n)
tendstoF : ∀ (x : (n : ℕ) → X n), Tendsto (fun x_1 ↦ F x_1 x) atTop (𝓝 (l x))
f_eq : ∀ (x : (n : ℕ) → X n) (n : ℕ), lmarginalPartialTraj κ k (a n) (f n) x = lmarginalPartialTraj κ k (k + 1) (F n) x
⊢ ∃ z,
    ∀ (x : (i : ℕ) → X i) (n : ℕ),
      ε ≤ lmarginalPartialTraj κ (k + 1) (a n) (f n) (update (updateFinset x (Iic k) y) (k + 1) z)

Tactic:
have F_le n x : F n x ≤ bound := by
    simpa [F, lmarginalPartialTraj] using lintegral_le_const (ae_of_all _ fun z ↦ le_bound _ _)

Goal state after:
X : ℕ → Type u_1
inst✝¹ : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
f : ℕ → ((n : ℕ) → X n) → ℝ≥0∞
a : ℕ → ℕ
hcte : ∀ (n : ℕ), DependsOn (f n) ↑(Iic (a n))
mf : ∀ (n : ℕ), Measurable (f n)
bound : ℝ≥0∞
fin_bound : bound ≠ ∞
le_bound : ∀ (n : ℕ) (x : (n : ℕ) → X n), f n x ≤ bound
k : ℕ
anti : ∀ (x : (n : ℕ) → X n), Antitone fun n ↦ lmarginalPartialTraj κ (k + 1) (a n) (f n) x
l : ((n : ℕ) → X n) → ℝ≥0∞
htendsto : ∀ (x : (n : ℕ) → X n), Tendsto (fun n ↦ lmarginalPartialTraj κ (k + 1) (a n) (f n) x) atTop (𝓝 (l x))
ε : ℝ≥0∞
y : (i : ↥(Iic k)) → X ↑i
hpos : ∀ (x : (i : ℕ) → X i) (n : ℕ), ε ≤ lmarginalPartialTraj κ k (a n) (f n) (updateFinset x (Iic k) y)
x✝ : ∀ (n : ℕ), Nonempty (X n)
F : ℕ → ((n : ℕ) → X n) → ℝ≥0∞ := fun n ↦ lmarginalPartialTraj κ (k + 1) (a n) (f n)
tendstoF : ∀ (x : (n : ℕ) → X n), Tendsto (fun x_1 ↦ F x_1 x) atTop (𝓝 (l x))
f_eq : ∀ (x : (n : ℕ) → X n) (n : ℕ), lmarginalPartialTraj κ k (a n) (f n) x = lmarginalPartialTraj κ k (k + 1) (F n) x
F_le : ∀ (n : ℕ) (x : (n : ℕ) → X n), F n x ≤ bound
⊢ ∃ z,
    ∀ (x : (i : ℕ) → X i) (n : ℕ),
      ε ≤ lmarginalPartialTraj κ (k + 1) (a n) (f n) (update (updateFinset x (Iic k) y) (k + 1) z)
Module: Mathlib.Probability.Kernel.RadonNikodym

Goal state before:
pp: case pos
α : Type u_1
γ : Type u_2
mα : MeasurableSpace α
mγ : MeasurableSpace γ
hαγ : MeasurableSpace.CountableOrCountablyGenerated α γ
κ η : Kernel α γ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
a : α
s : Set γ
hs : MeasurableSet s
h_le : κ ≤ κ + η
hα : Countable α
h_ac : κ a ≪ (κ + η) a
⊢ ∫⁻ (x : γ) in s, ENNReal.ofReal ((∂κ a/∂(κ + η) a) x).toReal ∂(κ + η) a = (κ a) s

Tactic:
rw [← Measure.setLIntegral_rnDeriv h_ac]

Goal state after:
case pos
α : Type u_1
γ : Type u_2
mα : MeasurableSpace α
mγ : MeasurableSpace γ
hαγ : MeasurableSpace.CountableOrCountablyGenerated α γ
κ η : Kernel α γ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
a : α
s : Set γ
hs : MeasurableSet s
h_le : κ ≤ κ + η
hα : Countable α
h_ac : κ a ≪ (κ + η) a
⊢ ∫⁻ (x : γ) in s, ENNReal.ofReal ((∂κ a/∂(κ + η) a) x).toReal ∂(κ + η) a =
    ∫⁻ (x : γ) in s, (∂κ a/∂(κ + η) a) x ∂(κ + η) a
Module: Mathlib.Probability.Kernel.RadonNikodym

Goal state before:
pp: α : Type u_1
γ : Type u_2
mα : MeasurableSpace α
mγ : MeasurableSpace γ
hαγ : MeasurableSpace.CountableOrCountablyGenerated α γ
κ η : Kernel α γ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
h_le : κ ≤ κ + η
⊢ ((κ + η).withDensity fun a x ↦ 1) = κ + η

Tactic:
rw [withDensity_one']

Goal state after:
Module: Mathlib.Probability.Kernel.IonescuTulcea.PartialTraj

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ ∫⁻ (b_1 : (i : ↥(Ioc a b)) → X ↑i),
      f
        (updateFinset x₀ (Iic b)
          (_root_.IicProdIoc a b (frestrictLe a x₀, b_1))) ∂((partialTraj κ a b).map (restrict₂ ⋯)) (frestrictLe a x₀) =
    ∫⁻ (x : (i : ↥(Ioc a b)) → X ↑i),
      f (updateFinset x₀ (Ioc a b) x) ∂((partialTraj κ a b).map (restrict₂ ⋯)) (frestrictLe a x₀)

pp: case hf
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun a_1 ↦ f (updateFinset x₀ (Iic b) (_root_.IicProdIoc a b a_1))

pp: case hf
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable (_root_.IicProdIoc a b)

pp: case hg
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun z ↦ f (updateFinset x₀ (Iic b) z)

Tactic:
· congrm ∫⁻ _, f (fun i ↦ ?_) ∂_
    simp only [updateFinset, mem_Iic, IicProdIoc_def,
      frestrictLe_apply, mem_Ioc]
    split_ifs <;> try rfl
    all_goals lia

Goal state after:
case hf
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun a_1 ↦ f (updateFinset x₀ (Iic b) (_root_.IicProdIoc a b a_1))

case hf
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable (_root_.IicProdIoc a b)

case hg
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a b : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsSFiniteKernel (κ n)
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun z ↦ f (updateFinset x₀ (Iic b) z)
Module: Mathlib.Probability.Kernel.RadonNikodym

Goal state before:
pp: α : Type u_1
γ : Type u_2
mα : MeasurableSpace α
mγ : MeasurableSpace γ
hαγ : MeasurableSpace.CountableOrCountablyGenerated α γ
κ η : Kernel α γ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
s : Set γ
hs : MeasurableSet s
⊢ Measurable fun b ↦ ((κ b).singularPart (η b)) s

Tactic:
← κ.singularPart_eq_singularPart_measure,

Goal state after:
α : Type u_1
γ : Type u_2
mα : MeasurableSpace α
mγ : MeasurableSpace γ
hαγ : MeasurableSpace.CountableOrCountablyGenerated α γ
κ η : Kernel α γ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
s : Set γ
hs : MeasurableSet s
⊢ Measurable fun b ↦ ((κ.singularPart η) b) s
Module: Mathlib.Probability.Kernel.Composition.AbsolutelyContinuous

Goal state before:
pp: case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ η : Kernel α β
inst✝² : IsFiniteKernel κ
inst✝¹ : IsFiniteKernel η
inst✝ : MeasurableSpace.CountableOrCountablyGenerated α β
μ ν : Measure α
hκη : ∀ᵐ (a : α) ∂μ, κ a ⟂ₘ η a
hμ : SFinite μ
hν : SFinite ν
s : Set (α × β) := κ.mutuallySingularSet η
hs : MeasurableSet s
⊢ (ν ⊗ₘ η) s = 0 ∧ (μ ⊗ₘ κ) sᶜ = 0

Tactic:
compProd_apply hs,

Goal state after:
case pos
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
κ η : Kernel α β
inst✝² : IsFiniteKernel κ
inst✝¹ : IsFiniteKernel η
inst✝ : MeasurableSpace.CountableOrCountablyGenerated α β
μ ν : Measure α
hκη : ∀ᵐ (a : α) ∂μ, κ a ⟂ₘ η a
hμ : SFinite μ
hν : SFinite ν
s : Set (α × β) := κ.mutuallySingularSet η
hs : MeasurableSet s
⊢ ∫⁻ (a : α), (η a) (Prod.mk a ⁻¹' s) ∂ν = 0 ∧ (μ ⊗ₘ κ) sᶜ = 0