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

Goal state before:
pp: E : Type u_1
F : Type u_2
inst✝¹⁰ : NormedAddCommGroup E
inst✝⁹ : NormedSpace ℝ E
inst✝⁸ : MeasurableSpace E
inst✝⁷ : BorelSpace E
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace ℝ F
inst✝⁴ : MeasurableSpace F
inst✝³ : BorelSpace F
μ : Measure E
inst✝² : IsGaussian μ
inst✝¹ : SecondCountableTopologyEither E F
ν : Measure F
inst✝ : IsGaussian ν
L : StrongDual ℝ (E × F)
L₁ : E →L[ℝ] ℝ := L ∘SL ContinuousLinearMap.inl ℝ E F
hL₁ : L₁ = L ∘SL ContinuousLinearMap.inl ℝ E F
L₂ : F →L[ℝ] ℝ := L ∘SL ContinuousLinearMap.inr ℝ E F
hL₂ : L₂ = L ∘SL ContinuousLinearMap.inr ℝ E F
⊢ (∫ (x : E), ↑(L₁ x) ∂μ) * I - ↑Var[⇑L₁; μ] / 2 +
      ((∫ (x : F), ↑((L ∘SL ContinuousLinearMap.inr ℝ E F) x) ∂ν) * I -
        ↑Var[⇑(L ∘SL ContinuousLinearMap.inr ℝ E F); ν] / 2) =
    (∫ (x : E × F), ↑(L x) ∂μ.prod ν) * I - ↑Var[⇑L; μ.prod ν] / 2

Tactic:
← hL₂,

Goal state after:
E : Type u_1
F : Type u_2
inst✝¹⁰ : NormedAddCommGroup E
inst✝⁹ : NormedSpace ℝ E
inst✝⁸ : MeasurableSpace E
inst✝⁷ : BorelSpace E
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace ℝ F
inst✝⁴ : MeasurableSpace F
inst✝³ : BorelSpace F
μ : Measure E
inst✝² : IsGaussian μ
inst✝¹ : SecondCountableTopologyEither E F
ν : Measure F
inst✝ : IsGaussian ν
L : StrongDual ℝ (E × F)
L₁ : E →L[ℝ] ℝ := L ∘SL ContinuousLinearMap.inl ℝ E F
hL₁ : L₁ = L ∘SL ContinuousLinearMap.inl ℝ E F
L₂ : F →L[ℝ] ℝ := L ∘SL ContinuousLinearMap.inr ℝ E F
hL₂ : L₂ = L ∘SL ContinuousLinearMap.inr ℝ E F
⊢ (∫ (x : E), ↑(L₁ x) ∂μ) * I - ↑Var[⇑L₁; μ] / 2 + ((∫ (x : F), ↑(L₂ x) ∂ν) * I - ↑Var[⇑L₂; ν] / 2) =
    (∫ (x : E × F), ↑(L x) ∂μ.prod ν) * I - ↑Var[⇑L; μ.prod ν] / 2
Module: Mathlib.Probability.Distributions.Gaussian.Fernique

Goal state before:
pp: case convert_5
E : Type u_1
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
inst✝² : CompleteSpace E
inst✝¹ : SecondCountableTopology E
μ : Measure E
inst✝ : IsGaussian μ
p : ℝ≥0
C : ℝ
hC_pos : 0 < C
hC : Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ
hC_neg : Integrable (fun x ↦ rexp (-C * ‖x‖ ^ 2)) μ
⊢ 0 ∈ interior (integrableExpSet (fun x ↦ ‖x‖ ^ 2) μ)

Tactic:
have h_subset : Set.Ioo (-C) C ⊆ interior (integrableExpSet (fun x ↦ ‖x‖ ^ 2) μ) := by
    rw [IsOpen.subset_interior_iff isOpen_Ioo]
    exact fun x hx ↦ integrable_exp_mul_of_le_of_le hC_neg hC hx.1.le hx.2.le

Goal state after:
case convert_5
E : Type u_1
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
inst✝² : CompleteSpace E
inst✝¹ : SecondCountableTopology E
μ : Measure E
inst✝ : IsGaussian μ
p : ℝ≥0
C : ℝ
hC_pos : 0 < C
hC : Integrable (fun x ↦ rexp (C * ‖x‖ ^ 2)) μ
hC_neg : Integrable (fun x ↦ rexp (-C * ‖x‖ ^ 2)) μ
h_subset : Set.Ioo (-C) C ⊆ interior (integrableExpSet (fun x ↦ ‖x‖ ^ 2) μ)
⊢ 0 ∈ interior (integrableExpSet (fun x ↦ ‖x‖ ^ 2) μ)
Module: Mathlib.Probability.Distributions.Gaussian.HasGaussianLaw.Basic

Goal state before:
pp: Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
X : Ω → ℝ
h : HasGaussianLaw X P
⊢ gaussianReal (∫ (x : ℝ), id x ∂Measure.map X P) Var[id; Measure.map X P].toNNReal =
    gaussianReal (∫ (x : Ω), X x ∂P) Var[X; P].toNNReal

Tactic:
integral_map,

Goal state after:
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
X : Ω → ℝ
h : HasGaussianLaw X P
⊢ gaussianReal (∫ (x : Ω), id (X x) ∂P) Var[id; Measure.map X P].toNNReal =
    gaussianReal (∫ (x : Ω), X x ∂P) Var[X; P].toNNReal

case hφ
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
X : Ω → ℝ
h : HasGaussianLaw X P
⊢ AEMeasurable X P

case hfm
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
X : Ω → ℝ
h : HasGaussianLaw X P
⊢ AEStronglyMeasurable id (Measure.map X P)
Module: Mathlib.Probability.Distributions.Gaussian.HasGaussianLaw.Basic

Goal state before:
pp: Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : CompleteSpace E
inst✝¹ : InnerProductSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (t : E),
    charFun (Measure.map X P) t = cexp (↑(∫ (x : Ω), (fun ω ↦ ⟪t, X ω⟫) x ∂P) * I - ↑Var[fun ω ↦ ⟪t, X ω⟫; P] / 2)
t : E
⊢ cexp (↑(∫ (x : Ω), (fun ω ↦ ⟪t, X ω⟫) x ∂P) * I - ↑Var[fun ω ↦ ⟪t, X ω⟫; P] / 2) =
    cexp ((∫ (x : E), ↑((fun x ↦ ⟪t, x⟫) x) ∂Measure.map X P) * I - ↑Var[fun x ↦ ⟪t, x⟫; Measure.map X P] / 2)

Tactic:
integral_map,

Goal state after:
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : CompleteSpace E
inst✝¹ : InnerProductSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (t : E),
    charFun (Measure.map X P) t = cexp (↑(∫ (x : Ω), (fun ω ↦ ⟪t, X ω⟫) x ∂P) * I - ↑Var[fun ω ↦ ⟪t, X ω⟫; P] / 2)
t : E
⊢ cexp (↑(∫ (x : Ω), (fun ω ↦ ⟪t, X ω⟫) x ∂P) * I - ↑Var[fun ω ↦ ⟪t, X ω⟫; P] / 2) =
    cexp ((∫ (x : Ω), ↑((fun x ↦ ⟪t, x⟫) (X x)) ∂P) * I - ↑Var[fun x ↦ ⟪t, x⟫; Measure.map X P] / 2)

case hφ
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : CompleteSpace E
inst✝¹ : InnerProductSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (t : E),
    charFun (Measure.map X P) t = cexp (↑(∫ (x : Ω), (fun ω ↦ ⟪t, X ω⟫) x ∂P) * I - ↑Var[fun ω ↦ ⟪t, X ω⟫; P] / 2)
t : E
⊢ AEMeasurable X P

case hfm
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : CompleteSpace E
inst✝¹ : InnerProductSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (t : E),
    charFun (Measure.map X P) t = cexp (↑(∫ (x : Ω), (fun ω ↦ ⟪t, X ω⟫) x ∂P) * I - ↑Var[fun ω ↦ ⟪t, X ω⟫; P] / 2)
t : E
⊢ AEStronglyMeasurable (fun x ↦ ↑((fun x ↦ ⟪t, x⟫) x)) (Measure.map X P)
Module: Mathlib.Probability.Distributions.Gaussian.HasGaussianLaw.Basic

Goal state before:
pp: Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁴ : NormedAddCommGroup E
inst✝³ : MeasurableSpace E
inst✝² : BorelSpace E
X : Ω → E
inst✝¹ : NormedSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (L : StrongDual ℝ E), charFunDual (Measure.map X P) L = cexp (↑(∫ (x : Ω), (⇑L ∘ X) x ∂P) * I - ↑Var[⇑L ∘ X; P] / 2)
t : StrongDual ℝ E
⊢ cexp (↑(∫ (x : Ω), (⇑t ∘ X) x ∂P) * I - ↑Var[⇑t ∘ X; P] / 2) =
    cexp ((∫ (x : E), ↑(t x) ∂Measure.map X P) * I - ↑Var[⇑t; Measure.map X P] / 2)

Tactic:
integral_map,

Goal state after:
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁴ : NormedAddCommGroup E
inst✝³ : MeasurableSpace E
inst✝² : BorelSpace E
X : Ω → E
inst✝¹ : NormedSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (L : StrongDual ℝ E), charFunDual (Measure.map X P) L = cexp (↑(∫ (x : Ω), (⇑L ∘ X) x ∂P) * I - ↑Var[⇑L ∘ X; P] / 2)
t : StrongDual ℝ E
⊢ cexp (↑(∫ (x : Ω), (⇑t ∘ X) x ∂P) * I - ↑Var[⇑t ∘ X; P] / 2) =
    cexp ((∫ (x : Ω), ↑(t (X x)) ∂P) * I - ↑Var[⇑t; Measure.map X P] / 2)

case hφ
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁴ : NormedAddCommGroup E
inst✝³ : MeasurableSpace E
inst✝² : BorelSpace E
X : Ω → E
inst✝¹ : NormedSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (L : StrongDual ℝ E), charFunDual (Measure.map X P) L = cexp (↑(∫ (x : Ω), (⇑L ∘ X) x ∂P) * I - ↑Var[⇑L ∘ X; P] / 2)
t : StrongDual ℝ E
⊢ AEMeasurable X P

case hfm
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁴ : NormedAddCommGroup E
inst✝³ : MeasurableSpace E
inst✝² : BorelSpace E
X : Ω → E
inst✝¹ : NormedSpace ℝ E
inst✝ : IsFiniteMeasure P
hX : AEMeasurable X P
h :
  ∀ (L : StrongDual ℝ E), charFunDual (Measure.map X P) L = cexp (↑(∫ (x : Ω), (⇑L ∘ X) x ∂P) * I - ↑Var[⇑L ∘ X; P] / 2)
t : StrongDual ℝ E
⊢ AEStronglyMeasurable (fun x ↦ ↑(t x)) (Measure.map X P)
Module: Mathlib.Probability.BrownianMotion.GaussianProjectiveFamily

Goal state before:
pp: I : Finset ℝ≥0
s : ↥I
⊢ gaussianReal 0 Var[fun x ↦ x s; projectiveFamily I].toNNReal = gaussianReal 0 ↑s

Tactic:
variance_eval_projectiveFamily,

Goal state after:
I : Finset ℝ≥0
s : ↥I
⊢ gaussianReal 0 (↑↑s).toNNReal = gaussianReal 0 ↑s
Module: Mathlib.Probability.BrownianMotion.GaussianProjectiveFamily

Goal state before:
pp: I : Finset ℝ≥0
s t : ↥I
⊢ gaussianReal (∫ (x : ↥I → ℝ), x s - x t ∂projectiveFamily I)
      (Var[fun x ↦ x s; projectiveFamily I] - 2 * cov[fun x ↦ x s, fun x ↦ x t; projectiveFamily I] +
          Var[fun x ↦ x t; projectiveFamily I]).toNNReal =
    gaussianReal 0 (nndist ↑s ↑t)

pp: case hX
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x s) 2 (projectiveFamily I)

pp: case hY
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x t) 2 (projectiveFamily I)

pp: I : Finset ℝ≥0
s t : ↥I
⊢ HasGaussianLaw (fun x ↦ x s - x t) (projectiveFamily I)

Tactic:
variance_eval_projectiveFamily,

Goal state after:
I : Finset ℝ≥0
s t : ↥I
⊢ gaussianReal (∫ (x : ↥I → ℝ), x s - x t ∂projectiveFamily I)
      (↑↑s - 2 * cov[fun x ↦ x s, fun x ↦ x t; projectiveFamily I] + Var[fun x ↦ x t; projectiveFamily I]).toNNReal =
    gaussianReal 0 (nndist ↑s ↑t)

case hX
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x s) 2 (projectiveFamily I)

case hY
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x t) 2 (projectiveFamily I)

I : Finset ℝ≥0
s t : ↥I
⊢ HasGaussianLaw (fun x ↦ x s - x t) (projectiveFamily I)
Module: Mathlib.Probability.BrownianMotion.GaussianProjectiveFamily

Goal state before:
pp: I : Finset ℝ≥0
s t : ↥I
⊢ gaussianReal (∫ (x : ↥I → ℝ), x s - x t ∂projectiveFamily I)
      (↑↑s - 2 * cov[fun x ↦ x s, fun x ↦ x t; projectiveFamily I] + Var[fun x ↦ x t; projectiveFamily I]).toNNReal =
    gaussianReal 0 (nndist ↑s ↑t)

pp: case hX
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x s) 2 (projectiveFamily I)

pp: case hY
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x t) 2 (projectiveFamily I)

pp: I : Finset ℝ≥0
s t : ↥I
⊢ HasGaussianLaw (fun x ↦ x s - x t) (projectiveFamily I)

Tactic:
variance_eval_projectiveFamily,

Goal state after:
I : Finset ℝ≥0
s t : ↥I
⊢ gaussianReal (∫ (x : ↥I → ℝ), x s - x t ∂projectiveFamily I)
      (↑↑s - 2 * cov[fun x ↦ x s, fun x ↦ x t; projectiveFamily I] + ↑↑t).toNNReal =
    gaussianReal 0 (nndist ↑s ↑t)

case hX
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x s) 2 (projectiveFamily I)

case hY
I : Finset ℝ≥0
s t : ↥I
⊢ MemLp (fun x ↦ x t) 2 (projectiveFamily I)

I : Finset ℝ≥0
s t : ↥I
⊢ HasGaussianLaw (fun x ↦ x s - x t) (projectiveFamily I)
Module: Mathlib.Probability.Distributions.Gaussian.HasGaussianLaw.Basic

Goal state before:
pp: Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SecondCountableTopology E
hX : HasGaussianLaw X P
p : ℝ≥0∞
hp : p ≠ ∞
⊢ MemLp X p P

Tactic:
rw [← Function.id_comp X, ← memLp_map_measure_iff]

Goal state after:
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SecondCountableTopology E
hX : HasGaussianLaw X P
p : ℝ≥0∞
hp : p ≠ ∞
⊢ MemLp id p (Measure.map X P)

case hg
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SecondCountableTopology E
hX : HasGaussianLaw X P
p : ℝ≥0∞
hp : p ≠ ∞
⊢ AEStronglyMeasurable id (Measure.map X P)

case hf
Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SecondCountableTopology E
hX : HasGaussianLaw X P
p : ℝ≥0∞
hp : p ≠ ∞
⊢ AEMeasurable X P

Ω : Type u_1
E : Type u_2
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
X : Ω → E
inst✝² : NormedSpace ℝ E
inst✝¹ : CompleteSpace E
inst✝ : SecondCountableTopology E
hX : HasGaussianLaw X P
p : ℝ≥0∞
hp : p ≠ ∞
⊢ MeasurableSpace E
Module: Mathlib.Probability.BrownianMotion.GaussianProjectiveFamily

Goal state before:
pp: I : Finset ℝ≥0
s t : ↥I
⊢ Measure.map (fun x ↦ x s - x t) (projectiveFamily I) = gaussianReal 0 (nndist ↑s ↑t)

Tactic:
rw [HasGaussianLaw.map_eq_gaussianReal, variance_fun_sub,
      variance_eval_projectiveFamily, variance_eval_projectiveFamily,
      covariance_eval_projectiveFamily, integral_sub]
    · congr
      · simp
      norm_cast
      rw [sub_add_eq_add_sub, ← NNReal.coe_add, ← NNReal.coe_sub, Real.toNNReal_coe]
      · wlog hst : (s : ℝ≥0) ≤ t generalizing s t
        · convert this t s (le_of_not_ge hst) using 1
          · rw [add_comm, min_comm]
          · rw [nndist_comm]
        grw [min_eq_left hst, NNReal.nndist_eq, max_eq_right (by grw [hst]), two_mul,
          add_tsub_add_eq_tsub_left]
      nth_grw 1 [two_mul, min_le_left, min_le_right]
    · exact (IsGaussian.hasGaussianLaw_id.eval s).integrable
    · exact (IsGaussian.hasGaussianLaw_id.eval t).integrable
    · exact (IsGaussian.hasGaussianLaw_id.eval s).memLp_two
    · exact (IsGaussian.hasGaussianLaw_id.eval t).memLp_two
    · exact (IsGaussian.hasGaussianLaw_id.prodMk s t).sub

Goal state after:
Module: Mathlib.Probability.Process.FiniteDimensionalLaws

Goal state before:
pp: case refine_1
T : Type u_1
Ω : Type u_2
𝓧 : T → Type u_3
mΩ : MeasurableSpace Ω
mα : (t : T) → MeasurableSpace (𝓧 t)
X Y : (t : T) → Ω → 𝓧 t
P : Measure Ω
inst✝ : IsFiniteMeasure P
hX : AEMeasurable (fun ω x ↦ X x ω) P
hY : AEMeasurable (fun ω x ↦ Y x ω) P
h : IdentDistrib (fun ω x ↦ X x ω) (fun ω x ↦ Y x ω) P P
I : Finset T
⊢ AEMeasurable (fun ω ↦ I.restrict fun x ↦ X x ω) P

Tactic:
exact (Finset.measurable_restrict _).comp_aemeasurable hX

Goal state after:
Module: Mathlib.Probability.Distributions.Gaussian.IsGaussianProcess.Independence

Goal state before:
pp: T : Type u_1
Ω : Type u_2
E : Type u_3
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
inst✝² : SecondCountableTopology E
inst✝¹ : CompleteSpace E
S : T → Type u_4
X : (t : T) → S t → Ω → E
inst✝ : NormedSpace ℝ E
hX : IsGaussianProcess (fun p ω ↦ X p.fst p.snd ω) P
mX : ∀ (t : T) (s : S t), AEMeasurable (X t s) P
h :
  ∀ (t₁ t₂ : T), t₁ ≠ t₂ → ∀ (s₁ : S t₁) (s₂ : S t₂) (L₁ L₂ : StrongDual ℝ E), cov[⇑L₁ ∘ X t₁ s₁, ⇑L₂ ∘ X t₂ s₂; P] = 0
⊢ iIndepFun (fun t ω s ↦ X t s ω) P

Tactic:
by
  have := hX.isProbabilityMeasure
  classical
  refine iIndepFun.iIndepFun_process₀ mX fun I J ↦
    HasGaussianLaw.iIndepFun_of_covariance_strongDual ?_ fun i j hij L₁ L₂ ↦ ?_
  · let L : (I.sigma (fun i ↦ if hi : i ∈ I then J ⟨i, hi⟩ else ∅) → E) →L[ℝ] (i : I) → J i → E :=
      { toFun x i j := x ⟨⟨i, j⟩, by simp⟩
        map_add' x y := by ext; simp
        map_smul' c x := by ext; simp }
    exact (hX.hasGaussianLaw _).map L
  have h1 : L₁ ∘ (fun ω k ↦ X i k ω) = ∑ k : J i, (L₁ ∘L .single ℝ _ k) ∘ X i k := by
    ext; simp [-ContinuousLinearMap.comp_apply, ← L₁.sum_comp_single]
  have h2 : L₂ ∘ (fun ω k ↦ X j k ω) = ∑ k : J j, (L₂ ∘L .single ℝ _ k) ∘ X j k := by
    ext; simp [-ContinuousLinearMap.comp_apply, ← L₂.sum_comp_single]
  rw [h1, h2, covariance_sum_sum]
  · exact sum_eq_zero fun _ _ ↦ sum_eq_zero fun _ _ ↦ h i j (by simpa) ..
  · exact fun k ↦ ((hX.hasGaussianLaw_eval ⟨i, k⟩).map _).memLp_two
  · exact fun k ↦ ((hX.hasGaussianLaw_eval ⟨j, k⟩).map _).memLp_two

Goal state after:
Module: Mathlib.Probability.Distributions.Gaussian.IsGaussianProcess.Independence

Goal state before:
pp: T : Type u_1
Ω : Type u_2
E : Type u_3
mΩ : MeasurableSpace Ω
P : Measure Ω
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : MeasurableSpace E
inst✝³ : BorelSpace E
inst✝² : SecondCountableTopology E
inst✝¹ : CompleteSpace E
S : T → Type u_4
X : (t : T) → S t → Ω → E
inst✝ : InnerProductSpace ℝ E
hX : IsGaussianProcess (fun p ω ↦ X p.fst p.snd ω) P
mX : ∀ (t : T) (s : S t), AEMeasurable (X t s) P
h :
  ∀ (t₁ t₂ : T),
    t₁ ≠ t₂ → ∀ (s₁ : S t₁) (s₂ : S t₂) (x y : E), cov[fun ω ↦ ⟪x, X t₁ s₁ ω⟫, fun ω ↦ ⟪y, X t₂ s₂ ω⟫; P] = 0
t₁ t₂ : T
ht : t₁ ≠ t₂
s₁ : S t₁
s₂ : S t₂
L₁ L₂ : StrongDual ℝ E
⊢ cov[⇑L₁ ∘ X t₁ s₁, ⇑L₂ ∘ X t₂ s₂; P] = 0

Tactic:
simpa using! h t₁ t₂ ht s₁ s₂ ((toDual ℝ E).symm L₁) ((toDual ℝ E).symm L₂)

Goal state after:
Module: Mathlib.Probability.BrownianMotion.Basic

Goal state before:
pp: case hm
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
this : IsGaussian (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P)
⊢ ∫ (x : WithLp 2 (↥I → ℝ)),
      id
        x ∂Measure.map (⇑(PiLp.continuousLinearEquiv 2 ℝ fun a ↦ ℝ).symm)
        (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P) =
    ∫ (x : WithLp 2 (↥I → ℝ)), id x ∂Measure.map (⇑(PiLp.continuousLinearEquiv 2 ℝ fun a ↦ ℝ).symm) (projectiveFamily I)

Tactic:
integral_map,

Goal state after:
case hm
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
this : IsGaussian (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P)
⊢ ∫ (x : ↥I → ℝ),
      id ((PiLp.continuousLinearEquiv 2 ℝ fun a ↦ ℝ).symm x) ∂Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P =
    ∫ (x : WithLp 2 (↥I → ℝ)), id x ∂Measure.map (⇑(PiLp.continuousLinearEquiv 2 ℝ fun a ↦ ℝ).symm) (projectiveFamily I)

case hm.hφ
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
this : IsGaussian (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P)
⊢ AEMeasurable (⇑(PiLp.continuousLinearEquiv 2 ℝ fun a ↦ ℝ).symm) (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P)

case hm.hfm
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
this : IsGaussian (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P)
⊢ AEStronglyMeasurable id
    (Measure.map (⇑(PiLp.continuousLinearEquiv 2 ℝ fun a ↦ ℝ).symm) (Measure.map (fun ω ↦ I.restrict fun x ↦ X x ω) P))
Module: Mathlib.Probability.Kernel.Disintegration.CDFToKernel

Goal state before:
pp: case pos
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
inst✝ : IsFiniteKernel κ
hf : IsRatCondKernelCDF f κ ν
a : α
x : ℝ
s : Set β
hs : MeasurableSet s
hρ_zero : (ν a).restrict s = 0
q : ℚ
hq : x < ↑q
⊢ (κ a).real (s ×ˢ Iic ↑q) = 0

Tactic:
rw [← hf.setIntegral a hs q]

Goal state after:
case pos
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
inst✝ : IsFiniteKernel κ
hf : IsRatCondKernelCDF f κ ν
a : α
x : ℝ
s : Set β
hs : MeasurableSet s
hρ_zero : (ν a).restrict s = 0
q : ℚ
hq : x < ↑q
⊢ ∫ (b : β) in s, f (a, b) q ∂ν a = 0
Module: Mathlib.Probability.Kernel.Disintegration.CDFToKernel

Goal state before:
pp: case e_f
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
inst✝ : IsFiniteKernel κ
hf : IsRatCondKernelCDF f κ ν
a : α
x : ℝ
s : Set β
hs : MeasurableSet s
hρ_zero : ¬(ν a).restrict s = 0
b : β
⊢ ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) x) =
    ⨅ r, ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) ↑↑r)

Tactic:
← measure_stieltjesOfMeasurableRat_Iic

Goal state after:
case e_f
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
inst✝ : IsFiniteKernel κ
hf : IsRatCondKernelCDF f κ ν
a : α
x : ℝ
s : Set β
hs : MeasurableSet s
hρ_zero : ¬(ν a).restrict s = 0
b : β
⊢ (stieltjesOfMeasurableRat f ⋯ (a, b)).measure (Iic x) = ⨅ r, (stieltjesOfMeasurableRat f ⋯ (a, b)).measure (Iic ↑↑r)
Module: Mathlib.Probability.Kernel.Disintegration.CDFToKernel

Goal state before:
pp: case neg.h_directed
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
inst✝ : IsFiniteKernel κ
hf : IsRatCondKernelCDF f κ ν
a : α
x : ℝ
s : Set β
hs : MeasurableSet s
hρ_zero : ¬(ν a).restrict s = 0
h :
  ∫⁻ (b : β) in s, ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) x) ∂ν a =
    ∫⁻ (b : β) in s, ⨅ r, ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) ↑↑r) ∂ν a
h_nonempty : Nonempty { r' // x < ↑r' }
i j : { r' // x < ↑r' }
hij : i ≤ j
b : β
⊢ ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) ↑↑i) ≤
    ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) ↑↑j)

Tactic:
← measure_stieltjesOfMeasurableRat_Iic

Goal state after:
case neg.h_directed
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
inst✝ : IsFiniteKernel κ
hf : IsRatCondKernelCDF f κ ν
a : α
x : ℝ
s : Set β
hs : MeasurableSet s
hρ_zero : ¬(ν a).restrict s = 0
h :
  ∫⁻ (b : β) in s, ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) x) ∂ν a =
    ∫⁻ (b : β) in s, ⨅ r, ENNReal.ofReal (↑(stieltjesOfMeasurableRat f ⋯ (a, b)) ↑↑r) ∂ν a
h_nonempty : Nonempty { r' // x < ↑r' }
i j : { r' // x < ↑r' }
hij : i ≤ j
b : β
⊢ (stieltjesOfMeasurableRat f ⋯ (a, b)).measure (Iic ↑↑i) ≤ (stieltjesOfMeasurableRat f ⋯ (a, b)).measure (Iic ↑↑j)
Module: Mathlib.Probability.BrownianMotion.Basic

Goal state before:
pp: Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ cov[B (t i.succ), B (t j.succ); P] - cov[B (t i.succ), B (t j.castSucc); P] - cov[B (t i.castSucc), B (t j.succ); P] +
      cov[B (t i.castSucc), B (t j.castSucc); P] =
    0

pp: case hX
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t i.succ)) 2 P

pp: case hY
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t i.castSucc)) 2 P

pp: case hZ
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t j.succ)) 2 P

pp: case hT
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t j.castSucc)) 2 P

Tactic:
· simp_rw [hB.covariance_fun_eval]
    wlog h : i < j generalizing i j
    · simp_rw [← this j i hij.symm (by grind), min_comm]
      grind
    have h1 : i.succ ≤ j.succ := Fin.strictMono_succ h |>.le
    have h2 : i.castSucc ≤ j.succ := Fin.le_of_lt h1
    have h3 : i.castSucc ≤ j.castSucc := Fin.le_castSucc_iff.mpr h1
    rw [min_eq_left (ht h1), min_eq_left (ht h), min_eq_left (ht h2), min_eq_left (ht h3)]
    simp

Goal state after:
case hX
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t i.succ)) 2 P

case hY
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t i.castSucc)) 2 P

case hZ
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t j.succ)) 2 P

case hT
Ω : Type u_1
mΩ : MeasurableSpace Ω
B : ℝ≥0 → Ω → ℝ
P : Measure Ω
hB : IsPreBrownianReal B P
this : IsProbabilityMeasure P
n : ℕ
t : Fin (n + 1) → ℝ≥0
ht : Monotone t
i j : Fin n
hij : i ≠ j
⊢ MemLp (B (t j.castSucc)) 2 P