OAI/Geometry/RCD/Coordinates/LocalCoordinateExtension.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Measurable extensions preserving the local metric approximation

  1. theorem OAI.RegularPointCoordinates.IsPointedApproximation.congr_on_ball line 15

    Source documentation

    Only values on the closed testing ball enter a pointed approximation.

    theorem IsPointedApproximation.congr_on_ball {Y : Type*} [MetricSpace Y]
        {p : X} {q : Y} {r R ε : ℝ} {f g : X → Y}
        (hRr : 0 ≤ R * r) (hf : IsPointedApproximation p q r R ε f)
        (hfg : EqOn f g (closedBall p (R * r))) :
        IsPointedApproximation p q r R ε g := by
    …

    Mentions: OAI.RegularPointCoordinates.IsPointedApproximation

  2. theorem OAI.RegularPointCoordinates.exists_measurable_local_extension line 31

    Source documentation

    A continuous local coordinate map has a measurable extension which agrees pointwise throughout its open domain.

    theorem exists_measurable_local_extension [MeasurableSpace X] [BorelSpace X]
        {n : ℕ} {s : Set X} (hs : MeasurableSet s) {v : X → Euclidean n}
        (hv : ContinuousOn v s) :
        ∃ v' : X → Euclidean n, Measurable v' ∧ EqOn v v' s := by
    …

    Mentions: OAI.RegularPointCoordinates.Euclidean