OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanOffsetThreshold.lean

GitHub source file

2 declarations, 0 contain sorry, 0 declared as axioms

Choosing the source enlargement before the sampled frames

  1. theorem OAI.PolycyclicRecognition.exists_source_offset_threshold line 14

    Source documentation

    The source enlargement and the vanishing-rate tolerance are chosen from the fixed metric constants and target restriction threshold. Neither depends on the source section, the sample, or the path-length constant.

    theorem exists_source_offset_threshold
        {A B Λ c target source : ℝ}
        (hA : 0 ≤ A) (hB : 0 ≤ B) (hΛ : 0 ≤ Λ) (hc : 0 ≤ c)
        (htarget : 0 < target) (hsource : 0 < source) :
        ∃ δ₀ ε : ℝ, 0 < δ₀ ∧ 0 < ε ∧ δ₀ ≤ source ∧
          ∀ δ : ℝ, 0 < δ → δ ≤ δ₀ →
            c * δ ≤ 1 ∧ Λ * (A * δ + B * ε) ≤ target := by
    …
  2. theorem OAI.PolycyclicRecognition.exists_uniform_source_offset_threshold line 48

    Source documentation

    A single source enlargement works for the finite family of possible affine labels and cone tests. The family is fixed before taking a limiting neighboring law.

    theorem exists_uniform_source_offset_threshold
        {I : Type*} [Finite I] [Nonempty I]
        {A B Λ c source : ℝ} (target : I → ℝ)
        (hA : 0 ≤ A) (hB : 0 ≤ B) (hΛ : 0 ≤ Λ) (hc : 0 ≤ c)
        (htarget : ∀ i, 0 < target i) (hsource : 0 < source) :
        ∃ δ₀ ε : ℝ, 0 < δ₀ ∧ 0 < ε ∧ δ₀ ≤ source ∧
          ∀ (i : I) (δ : ℝ), 0 < δ → δ ≤ δ₀ →
            c * δ ≤ 1 ∧ Λ * (A * δ + B * ε) ≤ target i := by
    …