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

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
t : ℕ → Set α
ht : ∀ (n : ℕ), MeasurableSet (t n)
ht_range : generateFrom (Set.range t) = m
⊢ generateFrom (Set.range t) = m

Tactic:
ht_range

Goal state after:
α : Type u_1
m : MeasurableSpace α
t : ℕ → Set α
ht : ∀ (n : ℕ), MeasurableSet (t n)
ht_range : generateFrom (Set.range t) = m
⊢ m = m
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
hκν : κ.fst ≤ ν
n : ℕ
a : α
x : γ
s : Set β
⊢ (κ a) (countablePartitionSet n x ×ˢ s) ≤ (ν a) (countablePartitionSet n x)

Tactic:
by
  calc κ a (countablePartitionSet n x ×ˢ s)
    ≤ fst κ a (countablePartitionSet n x) := by
        rw [fst_apply' _ _ (measurableSet_countablePartitionSet _ _)]
        refine measure_mono (fun x ↦ ?_)
        simp only [mem_prod, mem_ofPred_eq, and_imp]
        exact fun h _ ↦ h
  _ ≤ ν a (countablePartitionSet n x) := hκν a _

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

Goal state before:

Tactic:
∫⁻ b, hf.toKernel f (a, b) (Prod.mk b ⁻¹' tᶜ) ∂(ν a)
      = ∫⁻ b, hf.toKernel f (a, b) (Prod.mk b ⁻¹' t)ᶜ ∂(ν a) := rfl
    _ = ∫⁻ b, hf.toKernel f (a, b) univ
          - hf.toKernel f (a, b) (Prod.mk b ⁻¹' t) ∂(ν a) := by
        congr with x : 1
        exact measure_compl (measurable_prodMk_left ht)
          (measure_ne_top (hf.toKernel f (a, x)) _)
    _ = ∫⁻ x, hf.toKernel f (a, x) univ ∂(ν a) -
          ∫⁻ x, hf.toKernel f (a, x) (Prod.mk x ⁻¹' t) ∂(ν a) := by
        have h_le : (fun x ↦ hf.toKernel f (a, x) (Prod.mk x ⁻¹' t))
              ≤ᵐ[ν a] fun x ↦ hf.toKernel f (a, x) univ :=
          Eventually.of_forall fun _ ↦ measure_mono (subset_univ _)
        rw [lintegral_sub _ _ h_le]
        · exact Kernel.measurable_kernel_prodMk_left' ht a
        refine ((lintegral_mono_ae h_le).trans_lt ?_).ne
        rw [lintegral_toKernel_univ hf]
        exact measure_lt_top _ univ
    _ = κ a univ - κ a t := by rw [ht_eq, lintegral_toKernel_univ hf]
    _ = κ a tᶜ := (measure_compl ht (measure_ne_top _ _)).symm

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

Goal state before:
pp: case pos.right
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✝¹ : IsFiniteKernel κ.fst
inst✝ : κ.IsCondKernel κCond
a : α
h : κ.fst ⊗ₖ κCond = κ
h_sfin : IsSFiniteKernel κCond
h_eq : ∀ (s : Set β), MeasurableSet s → ∫⁻ (b : β), s.indicator (fun b ↦ (κCond (a, b)) univ) b ∂κ.fst a = (κ.fst a) s
h_meas : Measurable fun b ↦ (κCond (a, b)) univ
r : ℝ≥0∞
hr : r < 1
s : Set β := {b | (κCond (a, b)) univ ≤ r}
hs : MeasurableSet s
⊢ (κ.fst a) {x | (κCond (a, x)) univ ≤ r} = 0

Tactic:
have h_2_le : s.indicator (fun b ↦ (κCond (a, b)) Set.univ) ≤ s.indicator (fun _ ↦ r) := by
      intro b
      by_cases hbs : b ∈ s
      · simpa [hbs]
      · simp [hbs]

Goal state after:
case pos.right
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✝¹ : IsFiniteKernel κ.fst
inst✝ : κ.IsCondKernel κCond
a : α
h : κ.fst ⊗ₖ κCond = κ
h_sfin : IsSFiniteKernel κCond
h_eq : ∀ (s : Set β), MeasurableSet s → ∫⁻ (b : β), s.indicator (fun b ↦ (κCond (a, b)) univ) b ∂κ.fst a = (κ.fst a) s
h_meas : Measurable fun b ↦ (κCond (a, b)) univ
r : ℝ≥0∞
hr : r < 1
s : Set β := {b | (κCond (a, b)) univ ≤ r}
hs : MeasurableSet s
h_2_le : (s.indicator fun b ↦ (κCond (a, b)) univ) ≤ s.indicator fun x ↦ r
⊢ (κ.fst a) {x | (κCond (a, x)) univ ≤ r} = 0
Module: Mathlib.Probability.Kernel.Disintegration.Integral

Goal state before:
pp: α : Type u_1
β : Type u_2
Ω : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
inst✝⁴ : MeasurableSpace Ω
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
inst✝¹ : CountableOrCountablyGenerated α β
κ : Kernel α (β × Ω)
inst✝ : IsFiniteKernel κ
f : β × Ω → ℝ≥0∞
hf : Measurable f
a : α
⊢ ∫⁻ (b : β), ∫⁻ (ω : Ω), f (b, ω) ∂κ.condKernel (a, b) ∂κ.fst a = ∫⁻ (x : β × Ω), f x ∂(κ.fst ⊗ₖ κ.condKernel) a

Tactic:
Kernel.lintegral_compProd _ _ _ hf

Goal state after:
α : Type u_1
β : Type u_2
Ω : Type u_3
mα : MeasurableSpace α
mβ : MeasurableSpace β
inst✝⁴ : MeasurableSpace Ω
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
inst✝¹ : CountableOrCountablyGenerated α β
κ : Kernel α (β × Ω)
inst✝ : IsFiniteKernel κ
f : β × Ω → ℝ≥0∞
hf : Measurable f
a : α
⊢ ∫⁻ (b : β), ∫⁻ (ω : Ω), f (b, ω) ∂κ.condKernel (a, b) ∂κ.fst a =
    ∫⁻ (b : β), ∫⁻ (c : Ω), f (b, c) ∂κ.condKernel (a, b) ∂κ.fst a
Module: Mathlib.Probability.Kernel.Disintegration.Density

Goal state before:
pp: case hb
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
hκν : κ.fst ≤ ν
n : ℕ
a : α
x : γ
s s' : Set β
h : s ⊆ s'
h₀ : (ν a) (countablePartitionSet n x) ≠ 0
⊢ (κ a) (countablePartitionSet n x ×ˢ s') / (ν a) (countablePartitionSet n x) ≠ ∞

Tactic:
simp only [ne_eq, ENNReal.div_eq_top, h₀, and_false, false_or, not_and, not_not]

Goal state after:
case hb
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
hκν : κ.fst ≤ ν
n : ℕ
a : α
x : γ
s s' : Set β
h : s ⊆ s'
h₀ : (ν a) (countablePartitionSet n x) ≠ 0
⊢ (κ a) (countablePartitionSet n x ×ˢ s') = ∞ → (ν a) (countablePartitionSet n x) = ∞
Module: Mathlib.Probability.Kernel.Disintegration.Integral

Goal state before:
pp: β : Type u_1
Ω : Type u_2
mβ : MeasurableSpace β
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
ρ : Measure (β × Ω)
inst✝² : IsFiniteMeasure ρ
E : Type u_3
f : β × Ω → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hf : AEStronglyMeasurable f ρ
⊢ AEStronglyMeasurable (fun x ↦ ∫ (y : Ω), f (x, y) ∂ρ.condKernel x) ρ.fst

Tactic:
rw [← ρ.disintegrate ρ.condKernel] at hf

Goal state after:
β : Type u_1
Ω : Type u_2
mβ : MeasurableSpace β
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
ρ : Measure (β × Ω)
inst✝² : IsFiniteMeasure ρ
E : Type u_3
f : β × Ω → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hf : AEStronglyMeasurable f (ρ.fst ⊗ₘ ρ.condKernel)
⊢ AEStronglyMeasurable (fun x ↦ ∫ (y : Ω), f (x, y) ∂ρ.condKernel x) ρ.fst
Module: Mathlib.Probability.Kernel.Disintegration.Integral

Goal state before:
pp: β : Type u_1
Ω : Type u_2
mβ : MeasurableSpace β
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
ρ : Measure (β × Ω)
inst✝² : IsFiniteMeasure ρ
E : Type u_3
f : β × Ω → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hf : Integrable f ρ
⊢ ∫ (b : β), ∫ (ω : Ω), f (b, ω) ∂ρ.condKernel b ∂ρ.fst = ∫ (x : β × Ω), f x ∂ρ.fst ⊗ₘ ρ.condKernel

Tactic:
rw [← ρ.disintegrate ρ.condKernel] at hf

Goal state after:
β : Type u_1
Ω : Type u_2
mβ : MeasurableSpace β
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
ρ : Measure (β × Ω)
inst✝² : IsFiniteMeasure ρ
E : Type u_3
f : β × Ω → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
hf : Integrable f (ρ.fst ⊗ₘ ρ.condKernel)
⊢ ∫ (b : β), ∫ (ω : Ω), f (b, ω) ∂ρ.condKernel b ∂ρ.fst = ∫ (x : β × Ω), f x ∂ρ.fst ⊗ₘ ρ.condKernel
Module: Mathlib.Probability.Kernel.Disintegration.Integral

Goal state before:
pp: β : Type u_1
Ω : Type u_2
mβ : MeasurableSpace β
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
ρ : Measure (β × Ω)
inst✝² : IsFiniteMeasure ρ
E : Type u_3
f : β × Ω → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : Set β
hs : MeasurableSet s
t : Set Ω
ht : MeasurableSet t
hf : IntegrableOn f (s ×ˢ t) ρ
⊢ ∫ (b : β) in s, ∫ (ω : Ω) in t, f (b, ω) ∂ρ.condKernel b ∂ρ.fst = ∫ (x : β × Ω) in s ×ˢ t, f x ∂ρ.fst ⊗ₘ ρ.condKernel

Tactic:
rw [← ρ.disintegrate ρ.condKernel] at hf

Goal state after:
β : Type u_1
Ω : Type u_2
mβ : MeasurableSpace β
inst✝⁵ : MeasurableSpace Ω
inst✝⁴ : StandardBorelSpace Ω
inst✝³ : Nonempty Ω
ρ : Measure (β × Ω)
inst✝² : IsFiniteMeasure ρ
E : Type u_3
f : β × Ω → E
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace ℝ E
s : Set β
hs : MeasurableSet s
t : Set Ω
ht : MeasurableSet t
hf : IntegrableOn f (s ×ˢ t) (ρ.fst ⊗ₘ ρ.condKernel)
⊢ ∫ (b : β) in s, ∫ (ω : Ω) in t, f (b, ω) ∂ρ.condKernel b ∂ρ.fst = ∫ (x : β × Ω) in s ×ˢ t, f x ∂ρ.fst ⊗ₘ ρ.condKernel
Module: Mathlib.Probability.Kernel.Disintegration.Integral

Goal state before:
pp: α : Type u_1
Ω : Type u_2
F : Type u_4
mα : MeasurableSpace α
inst✝⁴ : MeasurableSpace Ω
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
inst✝¹ : NormedAddCommGroup F
ρ : Measure (α × Ω)
inst✝ : IsFiniteMeasure ρ
f : α × Ω → F
hf : AEStronglyMeasurable f ρ
⊢ (∀ᵐ (a : α) ∂ρ.fst, Integrable (fun ω ↦ f (a, ω)) (ρ.condKernel a)) ∧
      Integrable (fun a ↦ ∫ (ω : Ω), ‖f (a, ω)‖ ∂ρ.condKernel a) ρ.fst ↔
    Integrable f ρ

Tactic:
rw [← ρ.disintegrate ρ.condKernel] at hf

Goal state after:
α : Type u_1
Ω : Type u_2
F : Type u_4
mα : MeasurableSpace α
inst✝⁴ : MeasurableSpace Ω
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
inst✝¹ : NormedAddCommGroup F
ρ : Measure (α × Ω)
inst✝ : IsFiniteMeasure ρ
f : α × Ω → F
hf : AEStronglyMeasurable f (ρ.fst ⊗ₘ ρ.condKernel)
⊢ (∀ᵐ (a : α) ∂ρ.fst, Integrable (fun ω ↦ f (a, ω)) (ρ.condKernel a)) ∧
      Integrable (fun a ↦ ∫ (ω : Ω), ‖f (a, ω)‖ ∂ρ.condKernel a) ρ.fst ↔
    Integrable f ρ
Module: Mathlib.Probability.Kernel.Disintegration.Unique

Goal state before:
pp: α : Type u_1
Ω : Type u_3
mα : MeasurableSpace α
inst✝⁴ : MeasurableSpace Ω
inst✝³ : StandardBorelSpace Ω
inst✝² : Nonempty Ω
ρ : Measure (α × Ω)
inst✝¹ : IsFiniteMeasure ρ
κ : Kernel α Ω
inst✝ : IsFiniteKernel κ
hκ : ρ = ρ.fst ⊗ₘ κ
f : Ω → ℝ := embeddingReal Ω
hf : MeasurableEmbedding (embeddingReal Ω)
ρ' : Measure (α × ℝ) := Measure.map (Prod.map id f) ρ
hρ'def : ρ' = Measure.map (Prod.map id f) ρ
hρ' : ρ'.fst = ρ.fst
hρ'' : ∀ᵐ (x : α) ∂ρ.fst, (κ.map f) x = ρ'.condKernel x
s : Set (α × ℝ)
hs : MeasurableSet s
⊢ ∫⁻ (a : α), (ρ.condKernel a) (Prod.mk a ⁻¹' Prod.map id (embeddingReal Ω) ⁻¹' s) ∂ρ.fst =
    ∫⁻ (a : α), ((ρ.condKernel.map f) a) (Prod.mk a ⁻¹' s) ∂ρ.fst

Tactic:
congr with a
    rw [Kernel.map_apply' _ hf.measurable]
    exacts [rfl, measurable_prodMk_left hs]

Goal state after:
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
hgen : mγ = generateFrom {s | ∃ n, MeasurableSet s}
hpi : IsPiSystem {s | ∃ n, MeasurableSet s}
⊢ ∫ (x : γ) in A, κ.density ν a x s ∂ν a = (κ a).real (A ×ˢ s)

Tactic:
induction A, hA using induction_on_inter hgen hpi with
  | empty => simp
  | basic s hs =>
    rcases hs with ⟨n, hn⟩
    exact setIntegral_density_of_measurableSet hκν n a hs hn
  | compl A hA hA_eq =>
    have h := integral_add_compl hA (integrable_density hκν a hs)
    rw [hA_eq, integral_density hκν a hs] at h
    have : Aᶜ ×ˢ s = univ ×ˢ s \ A ×ˢ s := by
      rw [prod_sdiff_prod, compl_eq_univ_sdiff]
      simp
    rw [this, measureReal_def,
      measure_sdiff (by intro; simp) (hA.prod hs).nullMeasurableSet (measure_ne_top (κ a) _),
      ENNReal.toReal_sub_of_le (measure_mono (by intro x; simp)) (measure_ne_top _ _)]
    rw [eq_tsub_iff_add_eq_of_le, add_comm]
    · exact h
    · gcongr <;> simp
  | iUnion f hf_disj hf h_eq =>
    rw [integral_iUnion hf hf_disj (integrable_density hκν _ hs).integrableOn]
    simp_rw [h_eq, measureReal_def]
    rw [← ENNReal.tsum_toReal_eq (fun _ ↦ measure_ne_top _ _)]
    congr
    rw [iUnion_prod_const, measure_iUnion]
    · exact hf_disj.mono fun _ _ h ↦ h.set_prod_left _ _
    · exact fun i ↦ (hf i).prod hs

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

Goal state before:
pp: β : Type u_2
mβ : MeasurableSpace β
Ω : Type u_5
F : Type u_6
mΩ : MeasurableSpace Ω
X : Ω → β
μ : Measure Ω
inst✝ : TopologicalSpace F
f : Ω → F
hf : AEStronglyMeasurable f μ
⊢ (fun x ↦ f x.2) =ᵐ[Measure.map (fun ω ↦ (X ω, ω)) μ] fun x ↦ AEStronglyMeasurable.mk f hf x.2

Tactic:
suffices h : Measure.QuasiMeasurePreserving Prod.snd (μ.map fun ω ↦ (X ω, ω)) μ from
    Measure.QuasiMeasurePreserving.ae_eq h hf.ae_eq_mk

Goal state after:
β : Type u_2
mβ : MeasurableSpace β
Ω : Type u_5
F : Type u_6
mΩ : MeasurableSpace Ω
X : Ω → β
μ : Measure Ω
inst✝ : TopologicalSpace F
f : Ω → F
hf : AEStronglyMeasurable f μ
⊢ Measure.QuasiMeasurePreserving Prod.snd (Measure.map (fun ω ↦ (X ω, ω)) μ) μ
Module: Mathlib.Probability.Kernel.IonescuTulcea.Traj

Goal state before:
pp: X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (I : Finset ℕ) → Measure ((i : ↥I) → X ↑i)
hμ : IsProjectiveMeasureFamily μ
ν : Measure ((n : ℕ) → X n)
a : ℕ
h : ∀ ⦃n : ℕ⦄, a ≤ n → Measure.map (frestrictLe n) ν = μ (Iic n)
I : Finset ℕ
this : I ⊆ Iic (max (I.sup id) a)
⊢ Measure.map (restrict₂ this ∘ (Iic (max (I.sup id) a)).restrict) ν = μ I

Tactic:
← Measure.map_map,

Goal state after:
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (I : Finset ℕ) → Measure ((i : ↥I) → X ↑i)
hμ : IsProjectiveMeasureFamily μ
ν : Measure ((n : ℕ) → X n)
a : ℕ
h : ∀ ⦃n : ℕ⦄, a ≤ n → Measure.map (frestrictLe n) ν = μ (Iic n)
I : Finset ℕ
this : I ⊆ Iic (max (I.sup id) a)
⊢ Measure.map (restrict₂ this) (Measure.map (Iic (max (I.sup id) a)).restrict ν) = μ I

case hg
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (I : Finset ℕ) → Measure ((i : ↥I) → X ↑i)
hμ : IsProjectiveMeasureFamily μ
ν : Measure ((n : ℕ) → X n)
a : ℕ
h : ∀ ⦃n : ℕ⦄, a ≤ n → Measure.map (frestrictLe n) ν = μ (Iic n)
I : Finset ℕ
this : I ⊆ Iic (max (I.sup id) a)
⊢ Measurable (restrict₂ this)

case hf
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (I : Finset ℕ) → Measure ((i : ↥I) → X ↑i)
hμ : IsProjectiveMeasureFamily μ
ν : Measure ((n : ℕ) → X n)
a : ℕ
h : ∀ ⦃n : ℕ⦄, a ≤ n → Measure.map (frestrictLe n) ν = μ (Iic n)
I : Finset ℕ
this : I ⊆ Iic (max (I.sup id) a)
⊢ Measurable (Iic (max (I.sup id) a)).restrict

X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (I : Finset ℕ) → Measure ((i : ↥I) → X ↑i)
hμ : IsProjectiveMeasureFamily μ
ν : Measure ((n : ℕ) → X n)
a : ℕ
h : ∀ ⦃n : ℕ⦄, a ≤ n → Measure.map (frestrictLe n) ν = μ (Iic n)
I : Finset ℕ
this : I ⊆ Iic (max (I.sup id) a)
⊢ MeasurableSpace ((i : ↥(Iic (max (I.sup id) a))) → X ↑i)
Module: Mathlib.Probability.Distributions.SetBernoulli

Goal state before:
pp: ι : Type u_1
s : Set ι
p : ↑I
inst✝ : Countable ι
u : Finset ι
hsu : s ⊆ ↑u
⊢ ∀ x ∈ u,
    ((if x ∈ u ↔ x ∈ s then ↑(toNNReal p) else 0) + if x ∈ s then 0 else ↑(toNNReal (σ p))) =
      if x ∈ s then ↑(toNNReal p) else ↑(toNNReal (σ p))

Tactic:
simp +contextual [ite_add_ite, mt (@hsu _), ← ENNReal.coe_add]

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

Goal state before:
pp: ι : Type u_1
s : Set ι
p : ↑I
inst✝ : Countable ι
u : Finset ι
hsu : s ⊆ ↑u
⊢ ∀ b ∉ u, ((if b ∈ u ↔ b ∈ s then ↑(toNNReal p) else 0) + if b ∈ s then 0 else ↑(toNNReal (σ p))) = 1

Tactic:
simp +contextual [ite_add_ite, mt (@hsu _), ← ENNReal.coe_add]

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

Goal state before:
pp: X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measure.map (restrict₂ ⋯) (μ (J.sup id)) = Measure.map (restrict₂ ⋯ ∘ restrict₂ ⋯) (μ (I.sup id))

pp: case hg
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measurable (restrict₂ hJI)

pp: case hf
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measurable (restrict₂ ⋯)

Tactic:
← Measure.map_map,

Goal state after:
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measure.map (restrict₂ ⋯) (μ (J.sup id)) = Measure.map (restrict₂ ⋯) (Measure.map (restrict₂ ⋯) (μ (I.sup id)))

case hg
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measurable (restrict₂ ⋯)

case hf
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measurable (restrict₂ ⋯)

X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ MeasurableSpace ((i : ↥(Iic (J.sup id))) → X ↑i)

case hg
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measurable (restrict₂ hJI)

case hf
X : ℕ → Type u_1
inst✝ : (n : ℕ) → MeasurableSpace (X n)
μ : (n : ℕ) → Measure ((i : ↥(Iic n)) → X ↑i)
h : ∀ (a b : ℕ) (hab : a ≤ b), Measure.map (frestrictLe₂ hab) (μ b) = μ a
I J : Finset ℕ
hJI : J ⊆ I
sls : J.sup id ≤ I.sup id
⊢ Measurable (restrict₂ ⋯)
Module: Mathlib.Probability.ProductMeasure

Goal state before:
pp: case inr
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
hba : b ≤ a
⊢ map (frestrictLe₂ hba ∘ Prod.fst) ((Measure.pi fun i ↦ μ ↑i).prod (Measure.pi fun i ↦ μ ↑i)) = Measure.pi fun i ↦ μ ↑i

Tactic:
← Measure.map_map,

Goal state after:
case inr
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
hba : b ≤ a
⊢ map (frestrictLe₂ hba) (map Prod.fst ((Measure.pi fun i ↦ μ ↑i).prod (Measure.pi fun i ↦ μ ↑i))) =
    Measure.pi fun i ↦ μ ↑i

case inr.hg
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
hba : b ≤ a
⊢ Measurable (frestrictLe₂ hba)

case inr.hf
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
hba : b ≤ a
⊢ Measurable Prod.fst

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
hba : b ≤ a
⊢ MeasurableSpace ((i : ↥(Iic a)) → X ↑i)
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))
hba : b ≤ a
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:
exact mf.comp measurable_updateFinset

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

Goal state before:
pp: 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
h_eq : ∀ (a : α), Prod.mk a ⁻¹' s = κ.mutuallySingularSetSlice η a
h1 : ∀ (a : α), (η a) (Prod.mk a ⁻¹' s) = 0
a : α
ha : κ a ⟂ₘ η a
⊢ (κ a) (Prod.mk a ⁻¹' s)ᶜ = 0

Tactic:
rwa [h_eq, ← Kernel.withDensity_rnDeriv_eq_zero_iff_measure_eq_zero κ η a,
      Kernel.withDensity_rnDeriv_eq_zero_iff_mutuallySingular]

Goal state after:
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
h_eq : ∀ (a : α), Prod.mk a ⁻¹' s = κ.mutuallySingularSetSlice η a
h1 : ∀ (a : α), (η a) (Prod.mk a ⁻¹' s) = 0
⊢ ∫⁻ (a : α), (η a) (Prod.mk a ⁻¹' s) ∂ν = 0 ∧ ∫⁻ (a : α), (κ a) (Prod.mk a ⁻¹' sᶜ) ∂μ = 0

Tactic:
have h2 : ∀ᵐ a ∂μ, κ a (Prod.mk a ⁻¹' s)ᶜ = 0 := by
    filter_upwards [hκη] with a ha
    rwa [h_eq, ← Kernel.withDensity_rnDeriv_eq_zero_iff_measure_eq_zero κ η a,
      Kernel.withDensity_rnDeriv_eq_zero_iff_mutuallySingular]

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
h_eq : ∀ (a : α), Prod.mk a ⁻¹' s = κ.mutuallySingularSetSlice η a
h1 : ∀ (a : α), (η a) (Prod.mk a ⁻¹' s) = 0
h2 : ∀ᵐ (a : α) ∂μ, (κ a) (Prod.mk a ⁻¹' s)ᶜ = 0
⊢ ∫⁻ (a : α), (η a) (Prod.mk a ⁻¹' s) ∂ν = 0 ∧ ∫⁻ (a : α), (κ a) (Prod.mk a ⁻¹' sᶜ) ∂μ = 0
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✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : StandardBorelSpace Ω
inst✝ : Nonempty Ω
⊢ ⇑(Kernel.swap Ω 𝓧) ∘ₘ μ ⊗ₘ κ = ⇑(Kernel.swap Ω 𝓧) ∘ₘ ⇑(Kernel.id ∥ₖ κ) ∘ₘ ⇑(Kernel.copy Ω) ∘ₘ μ

Tactic:
Measure.compProd_eq_parallelComp_comp_copy_comp

Goal state after:
Ω : Type u_1
𝓧 : Type u_2
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝³ : IsFiniteMeasure μ
inst✝² : IsFiniteKernel κ
inst✝¹ : StandardBorelSpace Ω
inst✝ : Nonempty Ω
⊢ ⇑(Kernel.swap Ω 𝓧) ∘ₘ ⇑(Kernel.id ∥ₖ κ) ∘ₘ ⇑(Kernel.copy Ω) ∘ₘ μ =
    ⇑(Kernel.swap Ω 𝓧) ∘ₘ ⇑(Kernel.id ∥ₖ κ) ∘ₘ ⇑(Kernel.copy Ω) ∘ₘ μ
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✝⁴ : IsFiniteMeasure μ
inst✝³ : IsFiniteKernel κ
inst✝² : StandardBorelSpace Ω
inst✝¹ : Nonempty Ω
inst✝ : MeasurableSpace.CountableOrCountablyGenerated Ω 𝓧
h_ac : ∀ᵐ (ω : Ω) ∂μ, κ ω ≪ ⇑κ ∘ₘ μ
h1 :
  ∀ {s : Set Ω} {t : Set 𝓧},
    MeasurableSet s →
      MeasurableSet t →
        ∫⁻ (x : Ω × 𝓧) in s ×ˢ t, (κ†μ).rnDeriv (Kernel.const 𝓧 μ) x.2 x.1 ∂μ.prod (⇑κ ∘ₘ μ) = (μ ⊗ₘ κ) (s ×ˢ t)
s : Set Ω
t : Set 𝓧
hs : MeasurableSet s
ht : MeasurableSet t
⊢ ∫⁻ (x : Ω) in s, ∫⁻ (y : 𝓧) in t, κ.rnDeriv (Kernel.const Ω (⇑κ ∘ₘ μ)) (x, y).1 (x, y).2 ∂⇑κ ∘ₘ μ ∂μ =
    (μ ⊗ₘ κ) (s ×ˢ t)

Tactic:
Measure.compProd_apply_prod hs ht

Goal state after:
Ω : Type u_1
𝓧 : Type u_2
mΩ : MeasurableSpace Ω
m𝓧 : MeasurableSpace 𝓧
κ : Kernel Ω 𝓧
μ : Measure Ω
inst✝⁴ : IsFiniteMeasure μ
inst✝³ : IsFiniteKernel κ
inst✝² : StandardBorelSpace Ω
inst✝¹ : Nonempty Ω
inst✝ : MeasurableSpace.CountableOrCountablyGenerated Ω 𝓧
h_ac : ∀ᵐ (ω : Ω) ∂μ, κ ω ≪ ⇑κ ∘ₘ μ
h1 :
  ∀ {s : Set Ω} {t : Set 𝓧},
    MeasurableSet s →
      MeasurableSet t →
        ∫⁻ (x : Ω × 𝓧) in s ×ˢ t, (κ†μ).rnDeriv (Kernel.const 𝓧 μ) x.2 x.1 ∂μ.prod (⇑κ ∘ₘ μ) = (μ ⊗ₘ κ) (s ×ˢ t)
s : Set Ω
t : Set 𝓧
hs : MeasurableSet s
ht : MeasurableSet t
⊢ ∫⁻ (x : Ω) in s, ∫⁻ (y : 𝓧) in t, κ.rnDeriv (Kernel.const Ω (⇑κ ∘ₘ μ)) (x, y).1 (x, y).2 ∂⇑κ ∘ₘ μ ∂μ =
    ∫⁻ (a : Ω) in s, (κ a) t ∂μ