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

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure (X n)
inst✝ : ∀ (n : ℕ), SigmaFinite (μ n)
n : ℕ
s : (i : ↥(Ioc n (n + 1))) → Set (X ↑i)
hs : ∀ (i : ↥(Ioc n (n + 1))), MeasurableSet (s i)
this : Subsingleton ↥(Ioc n (n + 1))
⊢ Measurable ⇑(piSingleton n)

Tactic:
by fun_prop

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

Goal state before:
pp: α : Type u_1
β : Type u_2
ι : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
inst✝¹ : Countable ι
κ : Kernel α β
inst✝ : IsSFiniteKernel κ
f : ι → α → β → ℝ≥0∞
hf : ∀ (i : ι), Measurable (Function.uncurry (f i))
h_sum_a : ∀ (a : α), Summable fun n ↦ f n a
h_sum : Summable fun n ↦ f n
a : α
s : Set β
hs : MeasurableSet s
this : ∫⁻ (b : β) in s, (∑' (n : ι), f n) a b ∂κ a = ∫⁻ (b : β) in s, ∑' (n : ι), (fun b ↦ f n a b) b ∂κ a
n : ι
⊢ AEMeasurable (fun b ↦ f n a b) ((κ a).restrict s)

Tactic:
by fun_prop

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
F_le : ∀ (n : ℕ) (x : (n : ℕ) → X n), F n x ≤ bound
tendsto_int :
  ∀ (x : (n : ℕ) → X n),
    Tendsto (fun n ↦ lmarginalPartialTraj κ k (a n) (f n) x) atTop (𝓝 (lmarginalPartialTraj κ k (k + 1) l x))
ε_le_lint : ∀ (x : (i : ℕ) → X i), ε ≤ lmarginalPartialTraj κ k (k + 1) l (updateFinset x (Iic k) y)
x_ : (n : ℕ) → X n := Classical.ofNonempty
this : ∫⁻ (x : X (k + 1)), l (update (updateFinset x_ (Iic k) y) (k + 1) x) ∂(κ k) y ≠ ∞
x : X (k + 1)
hx :
  ∫⁻ (a : X (k + 1)), l (update (updateFinset x_ (Iic k) y) (k + 1) a) ∂(κ k) y ≤
    l (update (updateFinset x_ (Iic k) y) (k + 1) x)
⊢ ∀ (i : ℕ), Measurable (lmarginalPartialTraj κ (k + 1) (a i) (f i))

Tactic:
by fun_prop

Goal state after:
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
hα : Countable α
a a' : α
c : γ
ha'_mem_a : a' ∈ measurableAtom a
h_eq : ∀ (κ : Kernel α γ), κ a' = κ a
⊢ (∂κ a/∂η (a', c).1) (a', c).2 = (∂κ (a, c).1/∂η (a, c).1) (a, c).2

Tactic:
h_eq η

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
hα : Countable α
a a' : α
c : γ
ha'_mem_a : a' ∈ measurableAtom a
h_eq : ∀ (κ : Kernel α γ), κ a' = κ a
⊢ (∂κ a/∂η a) (a', c).2 = (∂κ (a, c).1/∂η (a, c).1) (a, c).2
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
a : α
⊢ Measurable fun x ↦ κ.rnDerivAux η a x

Tactic:
by fun_prop

Goal state after:
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
a : α
s : Set γ
hs : MeasurableSet s
h_le : κ ≤ κ + η
hα : ¬Countable α
this : MeasurableSpace.CountablyGenerated γ
⊢ Measurable fun a ↦ (a, ())

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
e : ℕ ≃ ι
I : Finset ι
S : Set ((i : ↥I) → X ↑i)
hS : MeasurableSet S
hs : cylinder I S ∈ measurableCylinders X
⊢ Measurable ⇑(Equiv.piCongrLeft (fun b ↦ X ↑b) (e.restrictPreimageFinset I))

Tactic:
by fun_prop

Goal state after:
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
a : α
⊢ Measurable fun x ↦ ENNReal.ofReal (1 - κ.rnDerivAux (κ + η) a x)

Tactic:
by fun_prop

Goal state after:
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
a : α
⊢ Measurable fun x ↦ κ.rnDeriv η a x

Tactic:
by fun_prop

Goal state after:
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
⊢ Measurable fun p ↦
    ↑(κ.rnDerivAux (κ + η) p.1 p.2).toNNReal - ↑(1 - κ.rnDerivAux (κ + η) p.1 p.2).toNNReal * κ.rnDeriv η p.1 p.2

Tactic:
by fun_prop

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

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a : ℕ
hp : (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ _root_.IicProdIoc a (a + 1) = ⇑(piSingleton a).symm ∘ Prod.snd
⊢ Measurable (_root_.IicProdIoc a (a + 1))

Tactic:
by fun_prop

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

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a : ℕ
hp : (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ _root_.IicProdIoc a (a + 1) = ⇑(piSingleton a).symm ∘ Prod.snd
⊢ Measurable fun x ↦ x ⟨a + 1, ⋯⟩

Tactic:
by fun_prop

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

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a : ℕ
hp : (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ _root_.IicProdIoc a (a + 1) = ⇑(piSingleton a).symm ∘ Prod.snd
⊢ Measurable Prod.snd

Tactic:
by fun_prop

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

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a : ℕ
hp : (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ _root_.IicProdIoc a (a + 1) = ⇑(piSingleton a).symm ∘ Prod.snd
⊢ Measurable ⇑(piSingleton a).symm

Tactic:
by fun_prop

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

Goal state before:
pp: X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a : ℕ
hp : (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ _root_.IicProdIoc a (a + 1) = ⇑(piSingleton a).symm ∘ Prod.snd
⊢ Measurable ⇑(piSingleton a)

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
A : ℕ → Set ((i : ι) → X i)
A_mem : ∀ (n : ℕ), A n ∈ measurableCylinders X
A_anti : Antitone A
A_inter : ⋂ n, A n = ∅
this : ∀ (i : ι), Nonempty (X i)
s : ℕ → Finset ι
S : (n : ℕ) → Set ((i : ↥(s n)) → X ↑i)
mS : ∀ (n : ℕ), MeasurableSet (S n)
A_eq : ∀ (n : ℕ), A n = cylinder (s n) (S n)
u : Set ι := ⋃ n, ↑(s n)
t : ℕ → Finset ↑u := fun n ↦ (s n).preimage Subtype.val ⋯
f : ((i : ↑u) → X ↑i) → (i : ι) → X i := fun x i ↦ if hi : i ∈ u then x ⟨i, hi⟩ else Classical.ofNonempty
aux : (n : ℕ) → ↥(t n) ≃ ↥(s n) :=
  fun n ↦ { toFun := fun i ↦ ⟨↑↑i, ⋯⟩, invFun := fun i ↦ ⟨⟨↑i, ⋯⟩, ⋯⟩, left_inv := ⋯, right_inv := ⋯ }
g : (n : ℕ) → ((a : ↥(t n)) → X ↑((aux n) a)) ≃ ((b : ↥(s n)) → X ↑b) :=
  fun n ↦ Equiv.piCongrLeft (fun i ↦ X ↑i) (aux n)
r_comp_f : ∀ (n : ℕ), (s n).restrict ∘ f = ⇑(g n) ∘ fun x i ↦ x ↑i
B : ℕ → Set ((i : ↑u) → X ↑i) := fun n ↦ f ⁻¹' A n
T : (n : ℕ) → Set ((a : ↥(t n)) → X ↑((aux n) a)) := fun n ↦ ⇑(g n) ⁻¹' S n
B_eq : ∀ (n : ℕ), B n = cylinder (t n) (T n)
n : ℕ
⊢ Measurable ⇑(g n)

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
A : ℕ → Set ((i : ι) → X i)
A_mem : ∀ (n : ℕ), A n ∈ measurableCylinders X
A_anti : Antitone A
A_inter : ⋂ n, A n = ∅
this : ∀ (i : ι), Nonempty (X i)
s : ℕ → Finset ι
S : (n : ℕ) → Set ((i : ↥(s n)) → X ↑i)
mS : ∀ (n : ℕ), MeasurableSet (S n)
A_eq : ∀ (n : ℕ), A n = cylinder (s n) (S n)
u : Set ι := ⋃ n, ↑(s n)
t : ℕ → Finset ↑u := fun n ↦ (s n).preimage Subtype.val ⋯
f : ((i : ↑u) → X ↑i) → (i : ι) → X i := fun x i ↦ if hi : i ∈ u then x ⟨i, hi⟩ else Classical.ofNonempty
aux : (n : ℕ) → ↥(t n) ≃ ↥(s n) :=
  fun n ↦ { toFun := fun i ↦ ⟨↑↑i, ⋯⟩, invFun := fun i ↦ ⟨⟨↑i, ⋯⟩, ⋯⟩, left_inv := ⋯, right_inv := ⋯ }
g : (n : ℕ) → ((a : ↥(t n)) → X ↑((aux n) a)) ≃ ((b : ↥(s n)) → X ↑b) :=
  fun n ↦ Equiv.piCongrLeft (fun i ↦ X ↑i) (aux n)
r_comp_f : ∀ (n : ℕ), (s n).restrict ∘ f = ⇑(g n) ∘ fun x i ↦ x ↑i
B : ℕ → Set ((i : ↑u) → X ↑i) := fun n ↦ f ⁻¹' A n
T : (n : ℕ) → Set ((a : ↥(t n)) → X ↑((aux n) a)) := fun n ↦ ⇑(g n) ⁻¹' S n
B_eq : ∀ (n : ℕ), B n = cylinder (t n) (T n)
mT : ∀ (n : ℕ), MeasurableSet (T n)
B_mem : ∀ (n : ℕ), B n ∈ measurableCylinders fun i ↦ X ↑i
mB : ∀ (n : ℕ), MeasurableSet (B n)
B_anti : Antitone B
B_inter : ⋂ n, B n = ∅
n : ℕ
⊢ Measurable ⇑(piCongrLeft (fun i ↦ X ↑i) (aux n))

Tactic:
by fun_prop

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 c : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
x₀ : (i : ↥(Iic a)) → X ↑i
hbc : b ≤ c
⊢ Measurable (frestrictLe₂ hbc)

Tactic:
by fun_prop

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

Goal state before:
pp: α : Type u_1
γ : Type u_2
mα : MeasurableSpace α
mγ : MeasurableSpace γ
κ η : Kernel α γ
hαγ : MeasurableSpace.CountableOrCountablyGenerated α γ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
a : α
s : Set γ
hsm : MeasurableSet s
hs : s ⊆ (κ.mutuallySingularSetSlice η a)ᶜ
⊢ ((η.withDensity (κ.rnDeriv η)) a) s = (κ a) s

Tactic:
have : withDensity η (rnDeriv κ η)
      = withDensity (withDensity (κ + η)
        (fun a x ↦ Real.toNNReal (1 - rnDerivAux κ (κ + η) a x))) (rnDeriv κ η) := by
    rw [rnDeriv_def']
    congr
    exact (withDensity_one_sub_rnDerivAux κ η).symm
  rw [this, ← withDensity_mul, Kernel.withDensity_apply']
  rotate_left
  · fun_prop
  · fun_prop
  · exact measurable_rnDeriv _ _
  simp_rw [rnDeriv]
  have hs' : ∀ x ∈ s, rnDerivAux κ (κ + η) a x < 1 := by
    simp_rw [← notMem_mutuallySingularSetSlice]
    exact fun x hx hx_mem ↦ hs hx hx_mem
  calc
    ∫⁻ x in s, ↑(Real.toNNReal (1 - rnDerivAux κ (κ + η) a x)) *
      (ENNReal.ofReal (rnDerivAux κ (κ + η) a x) /
        ENNReal.ofReal (1 - rnDerivAux κ (κ + η) a x)) ∂(κ + η) a
  _ = ∫⁻ x in s, ENNReal.ofReal (rnDerivAux κ (κ + η) a x) ∂(κ + η) a := by
      refine setLIntegral_congr_fun hsm (fun x hx ↦ ?_)
      rw [ofNNReal_toNNReal, ← ENNReal.ofReal_div_of_pos, div_eq_inv_mul, ← ENNReal.ofReal_mul,
        ← mul_assoc, mul_inv_cancel₀, one_mul]
      · rw [ne_eq, sub_eq_zero]
        exact (hs' x hx).ne'
      · simp [(hs' x hx).le]
      · simp [hs' x hx]
  _ = κ a s := setLIntegral_rnDerivAux κ η a hsm

Goal state after:
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 : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
a : α
this : univ = κ.mutuallySingularSetSlice η a ∪ (κ.mutuallySingularSetSlice η a)ᶜ
⊢ ((κ.singularPart η) a) (κ.mutuallySingularSetSlice η a) + 0 = 0 ↔
    ((κ.singularPart η) a) (κ.mutuallySingularSetSlice η a) = 0

Tactic:
add_zero

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 : IsSFiniteKernel κ
inst✝ : IsSFiniteKernel η
a : α
this : univ = κ.mutuallySingularSetSlice η a ∪ (κ.mutuallySingularSetSlice η a)ᶜ
⊢ ((κ.singularPart η) a) (κ.mutuallySingularSetSlice η a) = 0 ↔
    ((κ.singularPart η) a) (κ.mutuallySingularSetSlice η a) = 0
Module: Mathlib.Probability.Kernel.RadonNikodym

Goal state before:
pp: case refine_1
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
h : (κ.singularPart η) a = 0
⊢ (η.withDensity (κ.rnDeriv η)) a + 0 ≪ η a

Tactic:
add_zero

Goal state after:
case refine_1
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
h : (κ.singularPart η) a = 0
⊢ (η.withDensity (κ.rnDeriv η)) a ≪ η a
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)
A : ℕ → Set ((n : ℕ) → X n)
A_mem : ∀ (n : ℕ), A n ∈ measurableCylinders X
A_anti : Antitone A
A_inter : ⋂ n, A n = ∅
p : ℕ
x₀ : (i : ↥(Iic p)) → X ↑i
x✝ : ∀ (n : ℕ), Nonempty (X n)
a : ℕ → ℕ
S : (n : ℕ) → Set ((i : ↥(Iic (a n))) → X ↑i)
mS : ∀ (n : ℕ), MeasurableSet (S n)
A_eq : ∀ (n : ℕ), A n = cylinder (Iic (a n)) (S n)
χ : ℕ → ((n : ℕ) → X n) → ℝ≥0∞ := fun n ↦ (A n).indicator 1
mχ : ∀ (n : ℕ), Measurable (χ n)
χ_dep : ∀ (n : ℕ), DependsOn (χ n) ↑(Iic (a n))
lma_const :
  ∀ (x y : (i : ℕ) → X i) (n : ℕ),
    lmarginalPartialTraj κ p (a n) (χ n) (updateFinset x (Iic p) x₀) =
      lmarginalPartialTraj κ p (a n) (χ n) (updateFinset y (Iic p) x₀)
χ_anti : Antitone χ
lma_inv : ∀ (k M n : ℕ), a n ≤ M → lmarginalPartialTraj κ k M (χ n) = lmarginalPartialTraj κ k (a n) (χ n)
anti_lma : ∀ (k : ℕ) (x : (n : ℕ) → X n), Antitone fun n ↦ lmarginalPartialTraj κ k (a n) (χ n) x
l : ℕ → ((n : ℕ) → X n) → ℝ≥0∞
hl : ∀ (k : ℕ) (x : (n : ℕ) → X n), Tendsto (fun n ↦ lmarginalPartialTraj κ k (a n) (χ n) x) atTop (𝓝 (l k x))
l_const : ∀ (x y : (i : ℕ) → X i), l p (updateFinset x (Iic p) x₀) = l p (updateFinset y (Iic p) x₀)
ε : ℝ≥0∞
hε : ∀ (x : (i : ℕ) → X i), l p (updateFinset x (Iic p) x₀) = ε
hpos : ∀ (x : (i : ℕ) → X i) (n : ℕ), ε ≤ lmarginalPartialTraj κ p (a n) (χ n) (updateFinset x (Iic p) x₀)
χ_le : ∀ (n : ℕ) (x : (n : ℕ) → X n), χ n x ≤ 1
ind : (k : ℕ) → ((i : ↥(Iic k)) → X ↑i) → X (k + 1)
hind :
  ∀ (k : ℕ) (y : (i : ↥(Iic k)) → X ↑i),
    (∀ (x : (i : ℕ) → X i) (n : ℕ), ε ≤ lmarginalPartialTraj κ k (a n) (χ n) (updateFinset x (Iic k) y)) →
      ∀ (x : (i : ℕ) → X i) (n : ℕ),
        ε ≤ lmarginalPartialTraj κ (k + 1) (a n) (χ n) (update (updateFinset x (Iic k) y) (k + 1) (ind k y))
z : (n : ℕ) → X n := iterateInduction x₀ ind
k : ℕ
hk : p ≤ k
⊢ ∀ (x : (i : ℕ) → X i) (n : ℕ), ε ≤ lmarginalPartialTraj κ k (a n) (χ n) (updateFinset x (Iic k) (frestrictLe k z))

Tactic:
induction k, hk using Nat.le_induction with

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), IsMarkovKernel (κ n)
c : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
hf : DependsOn f ↑(Iic a)
hab : a ≤ b
x : (n : ℕ) → X n
⊢ Measurable (restrict₂ ⋯)

Tactic:
by fun_prop

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

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 : MeasurableSpace.CountableOrCountablyGenerated α β
inst✝² : IsFiniteMeasure μ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
h : μ ⊗ₘ κ = μ ⊗ₘ η
h_ac : ∀ᵐ (a : α) ∂μ, κ a ≪ η a
hκ_eq : ∀ᵐ (a : α) ∂μ, κ a = (η.withDensity (κ.rnDeriv η)) a
⊢ Measurable fun x ↦ κ.rnDeriv η x.1 x.2

Tactic:
by fun_prop

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

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 : MeasurableSpace.CountableOrCountablyGenerated α β
inst✝² : IsFiniteMeasure μ
inst✝¹ : IsFiniteKernel κ
inst✝ : IsFiniteKernel η
h : μ ⊗ₘ κ = μ ⊗ₘ η
h_ac : ∀ᵐ (a : α) ∂μ, κ a ≪ η a
hκ_eq : ∀ᵐ (a : α) ∂μ, κ a = (η.withDensity (κ.rnDeriv η)) a
⊢ Measurable fun x ↦ 1

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
I : Set ι
s : Finset ↑I
t : (i : ↑I) → Set (X ↑i)
ht : ∀ (i : ↑I), MeasurableSet (t i)
⊢ Measurable I.domRestrict

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι✝ : Type u_1
X✝ : ι✝ → Type u_2
mX✝ : (i : ι✝) → MeasurableSpace (X✝ i)
μ✝ : (i : ι✝) → Measure (X✝ i)
ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
s : Set ι
hs : Countable ↑s
t : (i : ι) → Set (X i)
mt : ∀ i ∈ s, MeasurableSet (t i)
s_ne : Nonempty ↑s
s' : Finset ↑s
⊢ Measurable s.domRestrict

Tactic:
by fun_prop

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

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
γ : Type u_3
inst✝³ : MeasurableSpace γ
κ : Kernel α β
η : Kernel β γ
inst✝² : IsMarkovKernel κ
inst✝¹ : IsMarkovKernel η
inst✝ : IsDeterministic (η ∘ₖ κ)
a : α
s : Set γ
t : Set β
hs : MeasurableSet s
ht : MeasurableSet t
this : ∀ (b : β), (η b) s * t.indicator 1 b = t.indicator (fun b ↦ (η b) s) b
h₁ : ((η ∘ₖ κ) a) s = 1
⊢ ∫⁻ (b : β) in t, (η b) s ∂κ a ≤ ∫⁻ (a : β) in t, 1 ∂κ a

Tactic:
refine lintegral_mono ?_

Goal state after:
α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
γ : Type u_3
inst✝³ : MeasurableSpace γ
κ : Kernel α β
η : Kernel β γ
inst✝² : IsMarkovKernel κ
inst✝¹ : IsMarkovKernel η
inst✝ : IsDeterministic (η ∘ₖ κ)
a : α
s : Set γ
t : Set β
hs : MeasurableSet s
ht : MeasurableSet t
this : ∀ (b : β), (η b) s * t.indicator 1 b = t.indicator (fun b ↦ (η b) s) b
h₁ : ((η ∘ₖ κ) a) s = 1
⊢ (fun b ↦ (η b) s) ≤ fun a ↦ 1
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)
a : ℕ
hf : (fun x ↦ x (a + 1)) = (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ frestrictLe (a + 1)
⊢ Measurable (frestrictLe (a + 1))

Tactic:
by fun_prop

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)
a : ℕ
hf : (fun x ↦ x (a + 1)) = (fun x ↦ x ⟨a + 1, ⋯⟩) ∘ frestrictLe (a + 1)
⊢ Measurable fun x ↦ x ⟨a + 1, ⋯⟩

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
i : ι
⊢ Measurable (Function.eval i)

Tactic:
by fun_prop

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

Goal state before:
pp: Ω : Type u_1
𝓧 : Type u_2
𝓨 : Type u_3
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
m𝓨 : MeasurableSpace 𝓨
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝⁶ : IsFiniteMeasure μ
inst✝⁵ : IsFiniteKernel κ
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
inst✝² : StandardBorelSpace 𝓧
inst✝¹ : Nonempty 𝓧
η : Kernel 𝓧 𝓨
inst✝ : IsFiniteKernel η
⊢ ⇑(Kernel.id ∥ₖ κ†μ ∘ₖ (η ∥ₖ Kernel.id)) ∘ₘ ⇑(Kernel.copy 𝓧) ∘ₘ ⇑κ ∘ₘ μ =
    ⇑(η ∥ₖ Kernel.id) ∘ₘ ⇑(Kernel.id ∥ₖ κ†μ) ∘ₘ ⇑(Kernel.copy 𝓧) ∘ₘ ⇑κ ∘ₘ μ

Tactic:
Kernel.parallelComp_comm,

Goal state after:
Ω : Type u_1
𝓧 : Type u_2
𝓨 : Type u_3
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
m𝓨 : MeasurableSpace 𝓨
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝⁶ : IsFiniteMeasure μ
inst✝⁵ : IsFiniteKernel κ
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
inst✝² : StandardBorelSpace 𝓧
inst✝¹ : Nonempty 𝓧
η : Kernel 𝓧 𝓨
inst✝ : IsFiniteKernel η
⊢ ⇑(η ∥ₖ Kernel.id ∘ₖ (Kernel.id ∥ₖ κ†μ)) ∘ₘ ⇑(Kernel.copy 𝓧) ∘ₘ ⇑κ ∘ₘ μ =
    ⇑(η ∥ₖ Kernel.id) ∘ₘ ⇑(Kernel.id ∥ₖ κ†μ) ∘ₘ ⇑(Kernel.copy 𝓧) ∘ₘ ⇑κ ∘ₘ μ
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
Y : ι → Type u_3
inst✝ : (i : ι) → MeasurableSpace (Y i)
f : (i : ι) → X i → Y i
hf : ∀ (i : ι), Measurable (f i)
this : ∀ (i : ι), IsProbabilityMeasure (map (f i) (μ i))
s : Finset ι
t : (i : ι) → Set (Y i)
ht : ∀ (i : ι), MeasurableSet (t i)
⊢ Measurable fun x i ↦ f i (x i)

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
mX : (i : ι) → MeasurableSpace (X i)
μ : (i : ι) → Measure (X i)
hμ : ∀ (i : ι), IsProbabilityMeasure (μ i)
Y : ι → Type u_3
inst✝ : (i : ι) → MeasurableSpace (Y i)
f : (i : ι) → X i → Y i
hf : ∀ (i : ι), Measurable (f i)
this✝ : ∀ (i : ι), IsProbabilityMeasure (map (f i) (μ i))
s : Finset ι
t : (i : ι) → Set (Y i)
ht : ∀ (i : ι), MeasurableSet (t i)
this : (fun x i ↦ f i (x i)) ⁻¹' (↑s).pi t = (↑s).pi fun i ↦ f i ⁻¹' t i
i : ι
hi : i ∈ s
⊢ Measurable (f i)

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.Decision.Risk.Basic

Goal state before:
pp: Θ : Type u_1
𝓧 : Type u_2
𝓨 : Type u_4
mΘ : MeasurableSpace Θ
m𝓧 : MeasurableSpace 𝓧
m𝓨 : MeasurableSpace 𝓨
ℓ : Θ → 𝓨 → ℝ≥0∞
hl : Measurable (uncurry ℓ)
μ : Measure 𝓧
inst✝² : SFinite μ
κ : Kernel 𝓧 𝓨
inst✝¹ : IsSFiniteKernel κ
π : Measure Θ
inst✝ : SFinite π
⊢ AEMeasurable (uncurry ℓ) (π.prod (⇑κ ∘ₘ μ))

Tactic:
by fun_prop

Goal state after:
Module: Mathlib.Probability.Decision.Risk.Basic

Goal state before:
pp: Θ : Type u_1
𝓧 : Type u_2
𝓨 : Type u_4
mΘ : MeasurableSpace Θ
m𝓧 : MeasurableSpace 𝓧
m𝓨 : MeasurableSpace 𝓨
ℓ : Θ → 𝓨 → ℝ≥0∞
hl : Measurable (uncurry ℓ)
P : Kernel Θ 𝓧
π : Measure Θ
y : 𝓨
θ : Θ
⊢ Measurable (ℓ θ)

Tactic:
by fun_prop

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

Goal state before:
pp: Ω : Type u_1
𝓧 : Type u_2
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝⁵ : IsFiniteMeasure μ
inst✝⁴ : IsFiniteKernel κ
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
inst✝¹ : MeasurableSpace.CountableOrCountablyGenerated Ω 𝓧
ν : Measure 𝓧
inst✝ : SFinite ν
h_ac : ∀ᵐ (ω : Ω) ∂μ, κ ω ≪ ν
⊢ ∀ᵐ (ω : Ω) ∂μ, κ ω ≪ ⇑κ ∘ₘ μ

Tactic:
rw [← absolutelyContinuous_posterior_iff]
  exact absolutelyContinuous_posterior h_ac

Goal state after: