Theorem: MeasureTheory.measure_univ_of_isMulLeftInvariant
File: Mathlib/MeasureTheory/Group/Measure.lean

Proof steps:
state_before: 𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
⊢ μ univ = ⊤
tactic: obtain ⟨K, K1, hK, Kclosed⟩ : ∃ K ∈ 𝓝 (1 : G), IsCompact K ∧ IsClosed K :=
    exists_mem_nhds_isCompact_isClosed 1
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
⊢ μ univ = ⊤
tactic: have K_pos : 0 < μ K := measure_pos_of_mem_nhds μ K1
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
A : ∀ (L : Set G), IsCompact L → ∃ g, Disjoint L (g • K)
⊢ μ univ = ⊤
tactic: have A : ∀ L : Set G, IsCompact L → ∃ g : G, Disjoint L (g • K) := fun L hL =>
    exists_disjoint_smul_of_isCompact hL hK
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
A : ∀ (L : Set G), IsCompact L → ∃ g, Disjoint L (g • K)
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
⊢ μ univ = ⊤
tactic: choose! g hg using A
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
⊢ μ univ = ⊤
tactic: set L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
N : Tendsto (fun n => μ (L n)) atTop (𝓝 (⊤ * μ K))
⊢ μ univ = ⊤
tactic: have N : Tendsto (fun n => μ (L n)) atTop (𝓝 (∞ * μ K)) := by
    simp_rw [M]
    apply ENNReal.Tendsto.mul_const _ (Or.inl ENNReal.top_ne_zero)
    exact ENNReal.tendsto_nat_nhds_top.comp (tendsto_add_atTop_nat _)
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
N : Tendsto (fun n => μ (L n)) atTop (𝓝 (⊤ * μ K))
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
N : Tendsto (fun n => μ (L n)) atTop (𝓝 ⊤)
⊢ μ univ = ⊤
tactic: simp only [ENNReal.top_mul', K_pos.ne', if_false] at N
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
N : Tendsto (fun n => μ (L n)) atTop (𝓝 ⊤)
⊢ μ univ = ⊤
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
N : Tendsto (fun n => μ (L n)) atTop (𝓝 ⊤)
⊢ ⊤ ≤ μ univ
tactic: apply top_le_iff.1
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝¹⁰ : MeasurableSpace G
inst✝⁹ : MeasurableSpace H
inst✝⁸ : TopologicalSpace G
inst✝⁷ : BorelSpace G
μ✝ : Measure G
inst✝⁶ : Group G
inst✝⁵ : TopologicalGroup G
inst✝⁴ : μ✝.IsMulLeftInvariant
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n => (fun T => T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed (L n)
M : ∀ (n : ℕ), μ (L n) = ↑(n + 1) * μ K
N : Tendsto (fun n => μ (L n)) atTop (𝓝 ⊤)
⊢ ⊤ ≤ μ univ
state_after: no goals
tactic: exact le_of_tendsto' N fun n => measure_mono (subset_univ _)