Module: Mathlib.Probability.Independence.CharacteristicFunction

Goal state before:
pp: 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
e : ↥(insert i s) → ι := Subtype.val
⊢ ∑ x ∈ s, X x = ∑ j with ↑j ∈ s, X ↑j

Tactic:
convert! (Finset.sum_of_injOn Subtype.val ?_ ?_ ?_ ?_).symm

Goal state after:
case convert_8
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
e : ↥(insert i s) → ι := Subtype.val
⊢ Set.InjOn Subtype.val ↑{x | ↑x ∈ s}

case convert_9
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
e : ↥(insert i s) → ι := Subtype.val
⊢ Set.MapsTo Subtype.val ↑{x | ↑x ∈ s} ↑s

case convert_10
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
e : ↥(insert i s) → ι := Subtype.val
⊢ ∀ i_1 ∈ s, i_1 ∉ Subtype.val '' ↑{x | ↑x ∈ s} → X i_1 = 0

case convert_11
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
e : ↥(insert i s) → ι := Subtype.val
⊢ ∀ i_1 ∈ {x | ↑x ∈ s}, X ↑i_1 = X ↑i_1