Theorem: MeasureTheory.Measure.isHaarMeasure_eq_of_isProbabilityMeasure
File: Mathlib/MeasureTheory/Measure/Haar/Unique.lean

tactic: have : CompactSpace G := by
  by_contra H
  rw [not_compactSpace_iff] at H
  simpa using measure_univ_of_isMulLeftInvariant μ
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
⊢ μ' = μ
state_after: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
⊢ μ' = μ

tactic: have A s : μ' s = haarScalarFactor μ' μ • μ s :=
  measure_isMulInvariant_eq_smul_of_isCompact_closure _ _ isClosed_closure.isCompact
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
⊢ μ' = μ
state_after: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
⊢ μ' = μ

tactic: have Z := A univ
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
⊢ μ' = μ
state_after: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
Z : μ' univ = μ'.haarScalarFactor μ • μ univ
⊢ μ' = μ

tactic: simp only [measure_univ, ENNReal.smul_def, smul_eq_mul, mul_one, ENNReal.one_eq_coe] at Z
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
Z : μ' univ = μ'.haarScalarFactor μ • μ univ
⊢ μ' = μ
state_after: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
Z : 1 = μ'.haarScalarFactor μ
⊢ μ' = μ

tactic: ext s _hs
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
Z : 1 = μ'.haarScalarFactor μ
⊢ μ' = μ
state_after: case h
G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
Z : 1 = μ'.haarScalarFactor μ
s : Set G
_hs : MeasurableSet s
⊢ μ' s = μ s

tactic: simp [A s, ← Z]
state_before: case h
G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
this : CompactSpace G
A : ∀ (s : Set G), μ' s = μ'.haarScalarFactor μ • μ s
Z : 1 = μ'.haarScalarFactor μ
s : Set G
_hs : MeasurableSet s
⊢ μ' s = μ s
state_after: no goals

tactic: by_contra H
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
⊢ CompactSpace G
state_after: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
H : ¬CompactSpace G
⊢ False

tactic: rw [not_compactSpace_iff] at H
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
H : ¬CompactSpace G
⊢ False
state_after: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
H : NoncompactSpace G
⊢ False

tactic: simpa using measure_univ_of_isMulLeftInvariant μ
state_before: G : Type u_1
inst✝⁹ : TopologicalSpace G
inst✝⁸ : Group G
inst✝⁷ : TopologicalGroup G
inst✝⁶ : MeasurableSpace G
inst✝⁵ : BorelSpace G
inst✝⁴ : LocallyCompactSpace G
μ' μ : Measure G
inst✝³ : IsProbabilityMeasure μ
inst✝² : IsProbabilityMeasure μ'
inst✝¹ : μ.IsHaarMeasure
inst✝ : μ'.IsHaarMeasure
H : NoncompactSpace G
⊢ False
state_after: no goals