Covering theorems for Lebesgue measure in one dimension #
We have a general theory of covering theorems for doubling measures, developed notably
in DensityTheorem.lean
. In this file, we expand the API for this theory in one dimension,
by showing that intervals belong to the relevant Vitali family.
theorem
Real.Icc_mem_vitaliFamily_at_right
{x y : ℝ}
(hxy : x < y)
:
Set.Icc x y ∈ (IsUnifLocDoublingMeasure.vitaliFamily MeasureTheory.volume 1).setsAt x
theorem
Real.tendsto_Icc_vitaliFamily_right
(x : ℝ)
:
Filter.Tendsto (fun (y : ℝ) => Set.Icc x y) (nhdsWithin x (Set.Ioi x))
((IsUnifLocDoublingMeasure.vitaliFamily MeasureTheory.volume 1).filterAt x)
theorem
Real.Icc_mem_vitaliFamily_at_left
{x y : ℝ}
(hxy : x < y)
:
Set.Icc x y ∈ (IsUnifLocDoublingMeasure.vitaliFamily MeasureTheory.volume 1).setsAt y
theorem
Real.tendsto_Icc_vitaliFamily_left
(x : ℝ)
:
Filter.Tendsto (fun (y : ℝ) => Set.Icc y x) (nhdsWithin x (Set.Iio x))
((IsUnifLocDoublingMeasure.vitaliFamily MeasureTheory.volume 1).filterAt x)