OAI/GroupTheory/PolycyclicRecognition/Geometry/SheetEndpointHeight.lean

GitHub source file

2 declarations, 0 contain sorry, 0 declared as axioms

Small endpoint heights at the common facet pivot

  1. theorem OAI.PolycyclicRecognition.common_profile_endpoint_height line 16

    Source documentation

    At one chart point only the common limiting value matters. In particular, the offset and linear part of the affine profile cancel.

    theorem common_profile_endpoint_height
        {G W Z : Type*} [Group G] [NormedAddCommGroup W] [NormedSpace ℝ W]
        (J : G → W) (x k l d : G) (r : ℝ) (φ : Z → G) (z₀ : Z) (c : W)
        (hd : φ z₀ = d) {ε : ℝ}
        (hk : ‖rescaledMapProfile J x k r φ z₀ - c‖ ≤ ε)
        (hl : ‖rescaledMapProfile J x l r φ z₀ - c‖ ≤ ε) :
        ‖J (x * l * d) - J (x * k * d)‖ ≤ 2 * Real.exp r * ε := by
    …

    Mentions: OAI.PolycyclicRecognition.rescaledMapProfile

  2. theorem OAI.PolycyclicRecognition.endpoint_height_of_short_bridges line 30

    Source documentation

    A short bridge at each endpoint adds twice its Lipschitz image to the endpoint height error. This is separate from control of the whole path.

    theorem endpoint_height_of_short_bridges
        {X W : Type*} [PseudoMetricSpace X] [NormedAddCommGroup W]
        (J : X → W) {K : ℝ≥0} (hJ : LipschitzWith K J)
        {a a' b' b : X} {δ B : ℝ}
        (ha : dist a a' ≤ δ) (hb : dist b' b ≤ δ)
        (hmid : ‖J b' - J a'‖ ≤ B) :
        ‖J b - J a‖ ≤ B + 2 * K * δ := by
    …