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

Goal state before:
pp: case hf
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 (Function.uncurry fun a x ↦ ENNReal.ofReal (1 - κ.rnDerivAux (κ + η) a x))

Tactic:
fun_prop

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

Goal state before:
pp: case inr.succ.hg
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), IsSFiniteKernel (κ n)
a b k : ℕ
h : a ≤ k
hk : partialTraj κ a k = (Kernel.id ×ₖ (partialTraj κ a k).map (restrict₂ ⋯)).map (_root_.IicProdIoc a k)
this :
  _root_.IicProdIoc k (k + 1) ∘ Prod.map (_root_.IicProdIoc a k) id =
    (⇑(MeasurableEquiv.IicProdIoc ⋯) ∘ Prod.map id (IocProdIoc a k (k + 1))) ∘ ⇑prodAssoc
⊢ Measurable (_root_.IicProdIoc k (k + 1))

Tactic:
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:
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:
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:
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:
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:
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:
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:
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:
fun_prop

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

Goal state before:
pp: case inl.hf
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 b : ℕ
hab : a ≤ b
this : IsMarkovKernel ((κ b).map ⇑(piSingleton b))
⊢ Measurable (_root_.IicProdIoc b (b + 1))

Tactic:
fun_prop

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

Goal state before:
pp: case inl.hg
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 b : ℕ
hab : a ≤ b
this : IsMarkovKernel ((κ b).map ⇑(piSingleton b))
⊢ Measurable (frestrictLe₂ ⋯)

Tactic:
fun_prop

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

Goal state before:
pp: case inr.hg
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 b : ℕ
hba : b < a
⊢ Measurable (frestrictLe₂ ⋯)

Tactic:
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:
fun_prop

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

Goal state before:
pp: case succ.hf
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
b c : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a k : ℕ
h : b ≤ k
hk : (partialTraj κ a k).map (frestrictLe₂ h) = partialTraj κ a b
⊢ Measurable (frestrictLe₂ ⋯)

Tactic:
fun_prop

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

Goal state before:
pp: case succ.hg
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
b c : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
inst✝ : ∀ (n : ℕ), IsMarkovKernel (κ n)
a k : ℕ
h : b ≤ k
hk : (partialTraj κ a k).map (frestrictLe₂ h) = partialTraj κ a b
⊢ Measurable (frestrictLe₂ h)

Tactic:
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:
fun_prop

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

Goal state before:
pp: case hf
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
this :
  η.withDensity (κ.rnDeriv η) =
    ((κ + η).withDensity fun a x ↦ ↑(1 - κ.rnDerivAux (κ + η) a x).toNNReal).withDensity (κ.rnDeriv η)
⊢ Measurable (Function.uncurry fun a x ↦ ↑(1 - κ.rnDerivAux (κ + η) a x).toNNReal * κ.rnDeriv η a x)

Tactic:
fun_prop

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

Goal state before:
pp: case hf
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
this :
  η.withDensity (κ.rnDeriv η) =
    ((κ + η).withDensity fun a x ↦ ↑(1 - κ.rnDerivAux (κ + η) a x).toNNReal).withDensity (κ.rnDeriv η)
⊢ Measurable (Function.uncurry fun a x ↦ (1 - κ.rnDerivAux (κ + η) a x).toNNReal)

Tactic:
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
this :
  η.withDensity (κ.rnDeriv η) =
    ((κ + η).withDensity fun a x ↦ ↑(1 - κ.rnDerivAux (κ + η) a x).toNNReal).withDensity (κ.rnDeriv η)
hs' : ∀ x ∈ s, κ.rnDerivAux (κ + η) a x < 1
x : γ
hx : x ∈ s
⊢ 0 < 1 - κ.rnDerivAux (κ + η) a x

Tactic:
simp [hs' x hx]

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

Goal state before:
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))

Tactic:
fun_prop

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

Goal state before:
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)

Tactic:
fun_prop

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

Goal state before:
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:
fun_prop

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

Goal state before:
pp: case hf
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), IsSFiniteKernel (κ n)
a : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable ⇑(piSingleton a)

Tactic:
fun_prop

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

Goal state before:
pp: case hg
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), IsSFiniteKernel (κ n)
a : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun b ↦ f (updateFinset x₀ (Iic (a + 1)) (_root_.IicProdIoc a (a + 1) (frestrictLe a x₀, b)))

Tactic:
fun_prop

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

Goal state before:
pp: case hf
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), IsSFiniteKernel (κ n)
a : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun a_1 ↦ f (updateFinset x₀ (Iic (a + 1)) (_root_.IicProdIoc a (a + 1) a_1))

Tactic:
fun_prop

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

Goal state before:
pp: case hf
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), IsSFiniteKernel (κ n)
a : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable (_root_.IicProdIoc a (a + 1))

Tactic:
fun_prop

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

Goal state before:
pp: case hg
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), IsSFiniteKernel (κ n)
a : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
mf : Measurable f
x₀ : (n : ℕ) → X n
⊢ Measurable fun z ↦ f (updateFinset x₀ (Iic (a + 1)) z)

Tactic:
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))
a b : ℕ
f : ((n : ℕ) → X n) → ℝ≥0∞
hf : Measurable f
g : ((i : ↥(Iic b)) → X ↑i) × ((n : ℕ) → X n) → ℝ≥0∞ := fun c ↦ f (updateFinset c.2 (Iic b) c.1)
η : Kernel ((n : ℕ) → X n) ((i : ↥(Iic b)) → X ↑i) := (partialTraj κ a b).comap (frestrictLe a) ⋯
⊢ Measurable fun x₀ ↦ ∫⁻ (z : (i : ↥(Iic b)) → X ↑i), g (z, x₀) ∂η x₀

Tactic:
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))
hab : a ≤ b
hbc : b ≤ c
f : ((n : ℕ) → X n) → ℝ≥0∞
hf : Measurable f
x₀ : (n : ℕ) → X n
⊢ lmarginalPartialTraj κ a b (lmarginalPartialTraj κ b c f) x₀ = lmarginalPartialTraj κ a c f x₀

Tactic:
obtain rfl | hab := eq_or_lt_of_le hab

Goal state after:
case inl
X : ℕ → Type u_1
mX : (n : ℕ) → MeasurableSpace (X n)
a c : ℕ
κ : (n : ℕ) → Kernel ((i : ↥(Iic n)) → X ↑i) (X (n + 1))
f : ((n : ℕ) → X n) → ℝ≥0∞
hf : Measurable f
x₀ : (n : ℕ) → X n
hab : a ≤ a
hbc : a ≤ c
⊢ lmarginalPartialTraj κ a a (lmarginalPartialTraj κ a c f) x₀ = lmarginalPartialTraj κ a c f x₀

case inr
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))
hab✝ : a ≤ b
hbc : b ≤ c
f : ((n : ℕ) → X n) → ℝ≥0∞
hf : Measurable f
x₀ : (n : ℕ) → X n
hab : a < b
⊢ lmarginalPartialTraj κ a b (lmarginalPartialTraj κ b c f) x₀ = lmarginalPartialTraj κ a c f x₀
Module: Mathlib.Probability.Kernel.IonescuTulcea.PartialTraj

Goal state before:
pp: case inr.inr.hg
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))
hab✝ : a ≤ b
hbc✝ : b ≤ c
f : ((n : ℕ) → X n) → ℝ≥0∞
hf : Measurable f
x₀ : (n : ℕ) → X n
hab : a < b
hbc : b < c
⊢ Measurable fun z ↦ f (updateFinset x₀ (Iic c) z)

Tactic:
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 : 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:
fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case a
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)
ν : Measure ((i : ι) → X i)
hν : ∀ (s : Finset ι) (t : (i : ι) → Set (X i)), (∀ (i : ι), MeasurableSet (t i)) → ν ((↑s).pi t) = ∏ i ∈ s, (μ i) (t i)
s : Finset ι
t : (i : ↥s) → Set (X ↑i)
ht : ∀ (i : ↥s), MeasurableSet (t i)
⊢ ∀ (i : ι), MeasurableSet (if h : i ∈ s then t ⟨i, h⟩ else Set.univ)

Tactic:
fun_prop

Goal state after:
case a
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)
ν : Measure ((i : ι) → X i)
hν : ∀ (s : Finset ι) (t : (i : ι) → Set (X i)), (∀ (i : ι), MeasurableSet (t i)) → ν ((↑s).pi t) = ∏ i ∈ s, (μ i) (t i)
s : Finset ι
t : (i : ↥s) → Set (X ↑i)
ht : ∀ (i : ↥s), MeasurableSet (t i)
⊢ ∀ (i : ι), MeasurableSet (if h : i ∈ s then t ⟨i, h⟩ else Set.univ)
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case hf
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)
ν : Measure ((i : ι) → X i)
hν : ∀ (s : Finset ι) (t : (i : ι) → Set (X i)), (∀ (i : ι), MeasurableSet (t i)) → ν ((↑s).pi t) = ∏ i ∈ s, (μ i) (t i)
s : Finset ι
t : (i : ↥s) → Set (X ↑i)
ht : ∀ (i : ↥s), MeasurableSet (t i)
⊢ Measurable s.restrict

Tactic:
fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case hs
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)
ν : Measure ((i : ι) → X i)
hν : ∀ (s : Finset ι) (t : (i : ι) → Set (X i)), (∀ (i : ι), MeasurableSet (t i)) → ν ((↑s).pi t) = ∏ i ∈ s, (μ i) (t i)
s : Finset ι
t : (i : ↥s) → Set (X ↑i)
ht : ∀ (i : ↥s), MeasurableSet (t i)
⊢ MeasurableSet (Set.univ.pi t)

Tactic:
fun_prop

Goal state after:
case hs
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)
ν : Measure ((i : ι) → X i)
hν : ∀ (s : Finset ι) (t : (i : ι) → Set (X i)), (∀ (i : ι), MeasurableSet (t i)) → ν ((↑s).pi t) = ∏ i ∈ s, (μ i) (t i)
s : Finset ι
t : (i : ↥s) → Set (X ↑i)
ht : ∀ (i : ↥s), MeasurableSet (t i)
⊢ MeasurableSet (Set.univ.pi t)
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:
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:
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
s : Set (α × β)
hs : MeasurableSet s
x✝ : (μ ⊗ₘ η) s < ∞
⊢ Measurable (Function.uncurry (κ.rnDeriv η))

Tactic:
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
𝓩 : Type u_4
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
m𝓨 : MeasurableSpace 𝓨
m𝓩 : MeasurableSpace 𝓩
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : StandardBorelSpace Ω
inst✝ : Nonempty Ω
⊢ IsMarkovKernel κ†μ

Tactic:
posterior

Goal state after:
Ω : Type u_1
𝓧 : Type u_2
𝓨 : Type u_3
𝓩 : Type u_4
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
m𝓨 : MeasurableSpace 𝓨
m𝓩 : MeasurableSpace 𝓩
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : StandardBorelSpace Ω
inst✝ : Nonempty Ω
⊢ IsMarkovKernel (Measure.map Prod.swap (μ ⊗ₘ κ)).condKernel
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:
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:
fun_prop

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

Goal state before:
pp: case hf
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 b : ℕ
x : (i : ↥(Iic a)) → X ↑i
s✝ : Set ((i : ↥(Iic b)) → X ↑i)
a✝ : MeasurableSet s✝
⊢ Measurable (frestrictLe b)

Tactic:
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 (frestrictLe (a + 1))

Tactic:
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:
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:
fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case hg
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
s : Set (X i)
hs : MeasurableSet s
this : Function.eval i = Function.eval ⟨i, ⋯⟩ ∘ {i}.restrict
⊢ Measurable (Function.eval ⟨i, ⋯⟩)

Tactic:
fun_prop

Goal state after:
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case hf
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
s : Set (X i)
hs : MeasurableSet s
this : Function.eval i = Function.eval ⟨i, ⋯⟩ ∘ {i}.restrict
⊢ Measurable {i}.restrict

Tactic:
fun_prop

Goal state after: