OAI/Geometry/RCD/Metric/HoleSourceBall.lean
2 declarations, 0 contain sorry, 0 declared as axioms
A target hole supplies a source ball outside the good set
- theorem
OAI.RegularPointCoordinates.coordinate_hole_liftline 13Source documentation
Lift the center of a missing target ball from its boundary contact. Only the pointed density clause is needed.
theorem coordinate_hole_lift {X : Type*} [MetricSpace X] {n : ℕ} {u : X → Euclidean n} {z : X} {c : Euclidean n} {r : ℝ} (hr : 0 < r) (htouch : dist (u z) c=r) (happ : IsPointedApproximation z 0 (64*r) (1/16) (1/128) (fun x => (64*r)⁻¹ • (u x-u z))) : ∃ x : X, dist x z ≤ 4*r ∧ dist (u x) c ≤ r/2 := by …Mentions: OAI.RegularPointCoordinates.Euclidean, OAI.RegularPointCoordinates.IsPointedApproximation
- theorem
OAI.RegularPointCoordinates.source_ball_avoids_good_setline 40Source documentation
A Lipschitz source ball around that lift maps strictly inside the hole, and therefore is disjoint from the original good set.
theorem source_ball_avoids_good_set {X : Type*} [MetricSpace X] {n : ℕ} {u : X → Euclidean n} {U Ω : Set X} {x : X} {c : Euclidean n} {r C : ℝ} (hr : 0 < r) (hC : 0 < C) (hsub : ball x (r/(4*C)) ⊆ Ω) (hlip : ∀ y ∈ Ω, dist (u y) (u x) ≤ C*dist y x) (hclose : dist (u x) c ≤ r/2) (hmiss : Disjoint (ball c r) (u '' U)) : (∀ y ∈ ball x (r/(4*C)), u y ∈ ball c r) ∧ Disjoint (ball x (r/(4*C))) U := by …Mentions: OAI.RegularPointCoordinates.Euclidean