OAI/Geometry/RCD/Metric/FiniteCoverIntegral.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Integrating finite covers with bounded overlap

  1. theorem OAI.RegularPointCoordinates.integral_le_sum_cover line 17

    Source documentation

    Integrate a nonnegative function over a finite cover, allowing overlap.

    theorem integral_le_sum_cover (s : Finset I) (A : I → Set X) (hA : ∀ i ∈ s, MeasurableSet (A i))
        {Ω : Set X} (hΩ : MeasurableSet Ω) (hcover : Ω ⊆ ⋃ i ∈ s, A i)
        {f : X → ℝ} (hf : Integrable f μ) (hpos : ∀ x, 0 ≤ f x) :
        (∫ x in Ω, f x ∂μ) ≤ ∑ i ∈ s, ∫ x in A i, f x ∂μ := by
    …
  2. theorem OAI.RegularPointCoordinates.sum_integral_le_overlap line 42

    Source documentation

    A bound on overlap controls the sum of local integrals by the global integral, with precisely the same multiplicity constant.

    theorem sum_integral_le_overlap (s : Finset I) (A : I → Set X)
        (hA : ∀ i ∈ s, MeasurableSet (A i)) (N : ℕ)
        (hoverlap : ∀ x, (s.filter (fun i => x ∈ A i)).card ≤ N)
        {f : X → ℝ} (hf : Integrable f μ) (hpos : ∀ x, 0 ≤ f x) :
        (∑ i ∈ s, ∫ x in A i, f x ∂μ) ≤ N * ∫ x, f x ∂μ := by
    …