Module: Mathlib.Probability.Independence.CharacteristicFunction

Goal state before:
pp: case insert
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
ι : Type u_2
s✝ : Finset ι
E : Type u_3
inst✝⁴ : MeasurableSpace E
inst✝³ : NormedAddCommGroup E
inst✝² : BorelSpace E
inst✝¹ : SecondCountableTopology E
X : ι → Ω → E
inst✝ : NormedSpace ℝ E
this : IsProbabilityMeasure P
i : ι
s : Finset ι
hi : i ∉ s
hs :
  (∀ i ∈ s, AEMeasurable (X i) P) →
    iIndepFun (s.restrict X) P → charFunDual (Measure.map (∑ i ∈ s, X i) P) = ∏ i ∈ s, charFunDual (Measure.map (X i) P)
mX : ∀ i_1 ∈ insert i s, AEMeasurable (X i_1) P
hX : iIndepFun ((insert i s).restrict X) P
⊢ charFunDual (Measure.map (X i + ∑ x ∈ s, X x) P) = ∏ i ∈ insert i s, charFunDual (Measure.map (X i) P)

Tactic:
IndepFun.charFunDual_map_add_eq_mul,

Goal state after:
case insert
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
ι : Type u_2
s✝ : Finset ι
E : Type u_3
inst✝⁴ : MeasurableSpace E
inst✝³ : NormedAddCommGroup E
inst✝² : BorelSpace E
inst✝¹ : SecondCountableTopology E
X : ι → Ω → E
inst✝ : NormedSpace ℝ E
this : IsProbabilityMeasure P
i : ι
s : Finset ι
hi : i ∉ s
hs :
  (∀ i ∈ s, AEMeasurable (X i) P) →
    iIndepFun (s.restrict X) P → charFunDual (Measure.map (∑ i ∈ s, X i) P) = ∏ i ∈ s, charFunDual (Measure.map (X i) P)
mX : ∀ i_1 ∈ insert i s, AEMeasurable (X i_1) P
hX : iIndepFun ((insert i s).restrict X) P
⊢ charFunDual (Measure.map (X i) P) * charFunDual (Measure.map (∑ x ∈ s, X x) P) =
    ∏ i ∈ insert i s, charFunDual (Measure.map (X i) P)

case insert.mX
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
ι : Type u_2
s✝ : Finset ι
E : Type u_3
inst✝⁴ : MeasurableSpace E
inst✝³ : NormedAddCommGroup E
inst✝² : BorelSpace E
inst✝¹ : SecondCountableTopology E
X : ι → Ω → E
inst✝ : NormedSpace ℝ E
this : IsProbabilityMeasure P
i : ι
s : Finset ι
hi : i ∉ s
hs :
  (∀ i ∈ s, AEMeasurable (X i) P) →
    iIndepFun (s.restrict X) P → charFunDual (Measure.map (∑ i ∈ s, X i) P) = ∏ i ∈ s, charFunDual (Measure.map (X i) P)
mX : ∀ i_1 ∈ insert i s, AEMeasurable (X i_1) P
hX : iIndepFun ((insert i s).restrict X) P
⊢ AEMeasurable (X i) P

case insert.mY
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
ι : Type u_2
s✝ : Finset ι
E : Type u_3
inst✝⁴ : MeasurableSpace E
inst✝³ : NormedAddCommGroup E
inst✝² : BorelSpace E
inst✝¹ : SecondCountableTopology E
X : ι → Ω → E
inst✝ : NormedSpace ℝ E
this : IsProbabilityMeasure P
i : ι
s : Finset ι
hi : i ∉ s
hs :
  (∀ i ∈ s, AEMeasurable (X i) P) →
    iIndepFun (s.restrict X) P → charFunDual (Measure.map (∑ i ∈ s, X i) P) = ∏ i ∈ s, charFunDual (Measure.map (X i) P)
mX : ∀ i_1 ∈ insert i s, AEMeasurable (X i_1) P
hX : iIndepFun ((insert i s).restrict X) P
⊢ AEMeasurable (∑ x ∈ s, X x) P

case insert.hXY
Ω : Type u_1
mΩ : MeasurableSpace Ω
P : Measure Ω
ι : Type u_2
s✝ : Finset ι
E : Type u_3
inst✝⁴ : MeasurableSpace E
inst✝³ : NormedAddCommGroup E
inst✝² : BorelSpace E
inst✝¹ : SecondCountableTopology E
X : ι → Ω → E
inst✝ : NormedSpace ℝ E
this : IsProbabilityMeasure P
i : ι
s : Finset ι
hi : i ∉ s
hs :
  (∀ i ∈ s, AEMeasurable (X i) P) →
    iIndepFun (s.restrict X) P → charFunDual (Measure.map (∑ i ∈ s, X i) P) = ∏ i ∈ s, charFunDual (Measure.map (X i) P)
mX : ∀ i_1 ∈ insert i s, AEMeasurable (X i_1) P
hX : iIndepFun ((insert i s).restrict X) P
⊢ X i ⟂ᵢ[P] ∑ x ∈ s, X x