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

Proof steps:
state_before: 𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
⊢ ∀ᶠ (g : G) in 𝓝 1, μ (g • k \ k) < ε
state_after: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
U : Set G
hUk : k ⊆ U
hU : IsOpen U
hμUk : μ U < μ k + ε
⊢ ∀ᶠ (g : G) in 𝓝 1, μ (g • k \ k) < ε
tactic: obtain ⟨U, hUk, hU, hμUk⟩ : ∃ (U : Set G), k ⊆ U ∧ IsOpen U ∧ μ U < μ k + ε :=
    hk.exists_isOpen_lt_add hε
state_before: case intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
U : Set G
hUk : k ⊆ U
hU : IsOpen U
hμUk : μ U < μ k + ε
⊢ ∀ᶠ (g : G) in 𝓝 1, μ (g • k \ k) < ε
state_after: case intro.intro.intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
U : Set G
hUk : k ⊆ U
hU : IsOpen U
hμUk : μ U < μ k + ε
V : Set G
hV1 : V ∈ 𝓝 1
hVkU : V * k ⊆ U
⊢ ∀ᶠ (g : G) in 𝓝 1, μ (g • k \ k) < ε
tactic: obtain ⟨V, hV1, hVkU⟩ : ∃ V ∈ 𝓝 (1 : G), V * k ⊆ U := compact_open_separated_mul_left hk hU hUk
state_before: case intro.intro.intro.intro.intro
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
U : Set G
hUk : k ⊆ U
hU : IsOpen U
hμUk : μ U < μ k + ε
V : Set G
hV1 : V ∈ 𝓝 1
hVkU : V * k ⊆ U
⊢ ∀ᶠ (g : G) in 𝓝 1, μ (g • k \ k) < ε
state_after: case h
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
U : Set G
hUk : k ⊆ U
hU : IsOpen U
hμUk : μ U < μ k + ε
V : Set G
hV1 : V ∈ 𝓝 1
hVkU : V * k ⊆ U
g : G
hg : g ∈ V
⊢ μ (g • k \ k) < ε
tactic: filter_upwards [hV1] with g hg
state_before: case h
𝕜 : Type u_1
G : Type u_2
H : Type u_3
inst✝⁸ : MeasurableSpace G
inst✝⁷ : MeasurableSpace H
inst✝⁶ : TopologicalSpace G
inst✝⁵ : BorelSpace G
μ : Measure G
inst✝⁴ : Group G
inst✝³ : TopologicalGroup G
inst✝² : LocallyCompactSpace G
inst✝¹ : IsFiniteMeasureOnCompacts μ
inst✝ : μ.InnerRegularCompactLTTop
k : Set G
hk : IsCompact k
h'k : IsClosed k
ε : ℝ≥0∞
hε : ε ≠ 0
U : Set G
hUk : k ⊆ U
hU : IsOpen U
hμUk : μ U < μ k + ε
V : Set G
hV1 : V ∈ 𝓝 1
hVkU : V * k ⊆ U
g : G
hg : g ∈ V
⊢ μ (g • k \ k) < ε
state_after: no goals
tactic: calc
    μ (g • k \ k) ≤ μ (U \ k) := by
      gcongr
      exact (smul_set_subset_smul hg).trans hVkU
    _ < ε := measure_diff_lt_of_lt_add h'k.measurableSet hUk hk.measure_lt_top.ne hμUk