OAI/Combinatorics/PlanarL1/Distance.lean

GitHub source file

73 declarations, 0 contain sorry, 0 declared as axioms

  1. lemma OAI.PlanarL1.Columns.Model.Point.paths_nonempty line 16
  2. def OAI.PlanarL1.Columns.Model.Point.distance line 21
  3. lemma OAI.PlanarL1.Columns.Model.Point.lengths_bddBelow line 24
  4. lemma OAI.PlanarL1.Columns.Model.Point.distance_le line 28
  5. lemma OAI.PlanarL1.Columns.Model.Point.distance_nonneg line 32
  6. lemma OAI.PlanarL1.Columns.Model.Point.height_change_le line 36
  7. lemma OAI.PlanarL1.Columns.Model.Point.distance_self line 40
  8. lemma OAI.PlanarL1.Columns.Model.Point.distance_triangle line 44
  9. lemma OAI.PlanarL1.Columns.Model.Point.distance_comm line 54
  10. instance OAI.PlanarL1.Columns.Model.Point.(instance at line 65) line 65
  11. lemma OAI.PlanarL1.Columns.Model.Point.dist_same_column line 73

    Source documentation

    The full vertical interval is isometric, before or after the quotient. No path's vertical variation can improve upon direct travel.

    lemma dist_same_column (x y : M.Point J root) (h : x.column = y.column) :
        dist x y = |x.height - y.height| := by
    …
  12. def OAI.PlanarL1.Columns.Model.Point.withHeight line 84

    Source documentation

    Vertical motion on a chosen column representative.

    def withHeight (x : M.Point J root) (H : ℝ) (hH : H ∈ J) : M.Point J root :=
    …
  13. lemma OAI.PlanarL1.Columns.Model.Point.withHeight_self line 87
  14. lemma OAI.PlanarL1.Columns.Model.Point.dist_withHeight line 90
  15. lemma OAI.PlanarL1.Columns.Model.Point.dist_le_switch line 93
  16. lemma OAI.PlanarL1.Columns.Model.Point.dist_midpoints_le line 100

    Source documentation

    The source's adjacent-midpoint estimate: one available switch costs at most the width of the band.

    lemma dist_midpoints_le (x y : M.Point J root) {H a : ℝ}
        (hx : x.height = H) (hy : y.height = H)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (h : (M.activeGraph J).Adj x.column y.column) : dist x y ≤ a := by
    …
  17. def OAI.PlanarL1.Columns.Model.Point.simpleLengths line 110

    Source documentation

    Lengths realized by words with no repeated column.

    def simpleLengths (x y : M.Point J root) : Set ℝ :=
    …
  18. lemma OAI.PlanarL1.Columns.Model.Point.mem_simpleLengths line 114
  19. lemma OAI.PlanarL1.Columns.Model.Point.simpleLengths_nonempty line 120
  20. lemma OAI.PlanarL1.Columns.Model.Point.isCompact_simpleLengths line 125
  21. lemma OAI.PlanarL1.Columns.Model.Point.exists_shortest line 137

    Source documentation

    Geometry, geo:geodesics: finite intrinsic distances are attained by a switching path with no repeated column. Compactness is required of the actual switch-height sets, rather than of an artificial discretization.

    lemma exists_shortest (hJ : IsClosed J) (x y : M.Point J root) :
        ∃ p : M.Path J x.column y.column,
          p.word.IsPath ∧ p.length x.height y.height = dist x y := by
    …
  22. lemma OAI.PlanarL1.Columns.Model.Point.dist_le_of_shared_column line 157

    Source documentation

    Two short paths whose projected words meet on a column give a short connection, with only one band-width paid for the vertical transfer.

    lemma dist_le_of_shared_column (x y : M.Point J root) {i j v : Fin n}
        (p : M.Path J x.column i) (q : M.Path J y.column j)
        {H T a : ℝ} (hH : H ∈ J) (hT : T ∈ J)
        (hwidth : ∀ r ∈ J, ∀ s ∈ J, |r - s| ≤ a)
        (hpv : v ∈ p.word.support) (hqv : v ∈ q.word.support) :
        dist x y ≤ p.length x.height H + q.length y.height T + a := by
    …
  23. lemma OAI.PlanarL1.Columns.Model.Point.zero_distance_iff line 178

    Source documentation

    The source's quotient identifies precisely finite chains of switches at a single height. This verifies that metric separation has not introduced any extra quotient relations.

    lemma zero_distance_iff (hJ : IsClosed J) (x y : M.Point J root) :
        dist x y = 0 ↔ x.height = y.height ∧
          (M.activeGraph {x.height}).Reachable x.column y.column := by
    …
  24. lemma OAI.PlanarL1.Columns.Model.Point.shortest_sublevel line 194

    Source documentation

    Exact shortest paths to a fixed-height column stay in its distance sublevel after projection to column indices. This is the metric assertion underlying geo:sublevel, not merely a graph-connectivity assumption.

    lemma shortest_sublevel (hJ : IsClosed J) (o y : M.Point J root) :
        ∃ p : M.Path J o.column y.column,
          p.length o.height y.height = dist o y ∧
          ∀ v ∈ p.word.support, ∃ hv : (M.activeGraph J).Reachable root v,
            dist o (⟨v, y.height, y.inBand, hv⟩ : M.Point J root) ≤ dist o y := by
    …
  25. def OAI.PlanarL1.Columns.Model.Point.sublevel line 213

    Source documentation

    The fixed-height radial sublevel in the active column graph. Columns outside the chosen component are absent, as for the source's value +∞.

    def sublevel (o : M.Point J root) (H : ℝ) (hH : H ∈ J) (t : ℝ) : Set (Fin n) :=
    …
  26. lemma OAI.PlanarL1.Columns.Model.Point.mem_sublevel_iff line 217
  27. lemma OAI.PlanarL1.Columns.Model.Point.sublevel_preconnected line 225
  28. lemma OAI.PlanarL1.Columns.Model.Point.sublevel_connected line 247

    Source documentation

    Geometry, Lemma geo:sublevel, including the actual nonemptiness hypothesis and connectivity in the induced graph, not merely in the ambient component.

    lemma sublevel_connected (hJ : IsClosed J) (o : M.Point J root)
        (H : ℝ) (hH : H ∈ J) (t : ℝ) (hne : (o.sublevel H hH t).Nonempty) :
        ((M.activeGraph J).induce (o.sublevel H hH t)).Connected := by
    …
  29. lemma OAI.PlanarL1.Columns.Model.Point.short_connector line 256

    Source documentation

    The short connector in the portal argument. We use the connected fixed-height sublevel at t - 12a; this changes the source's intermediate 13a estimate to 14a, still strictly below the required 100a separation.

    lemma short_connector (hJ : IsClosed J) (o x : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a) (ht : 30 * a ≤ t)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (hx : t ≤ dist o (x.withHeight H hH)) (hnear : dist o x < t + a) :
        ∃ v ∈ o.sublevel H hH (t - 12 * a), ∃ T ∈ J,
          ∃ p : M.Path J x.column v, p.length x.height T ≤ 14 * a := by
    …
  30. lemma OAI.PlanarL1.Columns.Model.Point.no_three_far_entrances line 299

    Source documentation

    Quantitative exclusion behind the two-portals lemma: three entrance-range midpoints in a connected high set cannot be mutually more than 100 widths apart. No minor-exclusion or short-connector hypothesis is assumed.

    lemma no_three_far_entrances (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        {C : Set (Fin n)} (hC : ((M.activeGraph J).induce C).Preconnected)
        (hhigh : ∀ z : M.Point J root, z.column ∈ C → t ≤ dist o (z.withHeight H hH))
        (x : Fin 3 → M.Point J root) (hxc : ∀ i, (x i).column ∈ C)
        (hnear : ∀ i, dist o (x i) < t + a)
        (hfar : Pairwise (fun i j => 100 * a < dist (x i) (x j))) : False := by
    …
  31. lemma OAI.PlanarL1.Columns.Model.Point.two_portal_midpoints line 355

    Source documentation

    Two entrances cover all entrance midpoints. The two chosen values may coincide, representing the one-portal case; both are actual entrances.

    lemma two_portal_midpoints (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        {C : Set (Fin n)} (hC : ((M.activeGraph J).induce C).Preconnected)
        (hhigh : ∀ z : M.Point J root, z.column ∈ C → t ≤ dist o (z.withHeight H hH))
        {E : Set (M.Point J root)} (hne : E.Nonempty)
        (heC : ∀ x ∈ E, x.column ∈ C) (hnear : ∀ x ∈ E, dist o x < t + a) :
        ∃ p ∈ E, ∃ q ∈ E, ∀ x ∈ E, dist x p ≤ 100 * a ∨ dist x q ≤ 100 * a := by
    …
  32. lemma OAI.PlanarL1.Columns.Model.Point.two_portals line 393

    Source documentation

    Geometry geo:portals, the full-column covering conclusion with the stated 200a constant. The entrance-range hypothesis is derived from adjacency by dist_midpoints_le; the two portal centers are selected from E itself.

    lemma two_portals (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        {C : Set (Fin n)} (hC : ((M.activeGraph J).induce C).Preconnected)
        (hhigh : ∀ z : M.Point J root, z.column ∈ C → t ≤ dist o (z.withHeight H hH))
        {E : Set (M.Point J root)} (hne : E.Nonempty)
        (heC : ∀ x ∈ E, x.column ∈ C) (hnear : ∀ x ∈ E, dist o x < t + a) :
        ∃ p ∈ E, ∃ q ∈ E, ∀ x : M.Point J root, x.withHeight H hH ∈ E →
          dist x p ≤ 200 * a ∨ dist x q ≤ 200 * a := by
    …
  33. def OAI.PlanarL1.Columns.Model.Point.superlevel line 417

    Source documentation

    Radial superlevels contain exactly the reachable columns whose midpoints have radial value at least the threshold.

    def superlevel (o : M.Point J root) (H : ℝ) (hH : H ∈ J) (t : ℝ) : Set (Fin n) :=
    …
  34. lemma OAI.PlanarL1.Columns.Model.Point.mem_superlevel_iff line 421
  35. def OAI.PlanarL1.Columns.Model.Point.entrances line 432

    Source documentation

    The actual entrance midpoints of a radial high component. The adjacent low column, rather than a separate entrance-range hypothesis, is part of the definition.

    def entrances (o : M.Point J root) (H : ℝ) (hH : H ∈ J) (t : ℝ)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent) :
        Set (M.Point J root) :=
    …
  36. lemma OAI.PlanarL1.Columns.Model.Point.entrance_radial line 439
  37. lemma OAI.PlanarL1.Columns.Model.Point.exit_superlevel line 458

    Source documentation

    Exit a high component along an attained shortest path. The final high column is an actual entrance. The estimate retains the distance to the radial threshold, and is the geometric input for both cell diameters and portal levels.

    lemma exit_superlevel (hJ : IsClosed J) (o x : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ht : a / 2 < t)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent)
        (hx : x.column ∈ ColumnOrder.componentColumns C) :
        ∃ z : M.Point J root, z.withHeight H hH ∈ o.entrances H hH t C ∧
          dist x z ≤ dist o x - t + a / 2 := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  38. lemma OAI.PlanarL1.Columns.Model.Point.entrances_nonempty line 505

    Source documentation

    Nonempty radial high components have entrances above the initial half-width. This discharges the existence clause of geo:portals.

    lemma entrances_nonempty (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ht : a / 2 < t)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent) :
        (o.entrances H hH t C).Nonempty := by
    …
  39. lemma OAI.PlanarL1.Columns.Model.Point.component_two_portals line 518

    Source documentation

    Geometry geo:portals with the actual radial component and actual entrances. In particular no covering or radial-range conclusion is assumed.

    lemma component_two_portals (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent)
        (hne : (o.entrances H hH t C).Nonempty) :
        ∃ p ∈ o.entrances H hH t C, ∃ q ∈ o.entrances H hH t C,
          (t ≤ dist o p ∧ dist o p < t + a) ∧
          (t ≤ dist o q ∧ dist o q < t + a) ∧
          ∀ x : M.Point J root, x.withHeight H hH ∈ o.entrances H hH t C →
            dist x p ≤ 200 * a ∨ dist x q ≤ 200 * a := by
    …
  40. lemma OAI.PlanarL1.Columns.Model.Point.component_portal_cover line 538

    Source documentation

    The geodesic-to-root estimate behind radial cells: every point of a high component whose radial distance is bounded is close to a chosen portal.

    lemma component_portal_cover (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a) (ht : a / 2 < t)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent) :
        ∃ p ∈ o.entrances H hH t C, ∃ q ∈ o.entrances H hH t C,
          ∀ x : M.Point J root, x.column ∈ ColumnOrder.componentColumns C →
            dist x p ≤ dist o x - t + 201 * a ∨
            dist x q ≤ dist o x - t + 201 * a := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  41. def OAI.PlanarL1.Columns.Model.Point.layer line 559

    Source documentation

    The half-open radial layer of the source. Its connected components, not components of the ambient graph, are the cell column sets.

    def layer (o : M.Point J root) (H : ℝ) (hH : H ∈ J) (q D : ℝ) : Set (Fin n) :=
    …
  42. lemma OAI.PlanarL1.Columns.Model.Point.layer_subset_superlevel line 564
  43. lemma OAI.PlanarL1.Columns.Model.Point.mem_layer_iff line 569
  44. lemma OAI.PlanarL1.Columns.Model.Point.radial_cell_diameter line 580

    Source documentation

    The weak-diameter assertion of geo:cells for the literal full-column cell. Paths measuring distance may leave the cell, exactly as in the source.

    lemma radial_cell_diameter (hJ : IsClosed J) (o : M.Point J root)
        {H a q D : ℝ} (hH : H ∈ J) (ha : 0 < a) (hthin : a ≤ D / 1000)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.layer H hH q D)).ConnectedComponent)
        (x y : M.Point J root) (hx : x.column ∈ ColumnOrder.componentColumns C)
        (hy : y.column ∈ ColumnOrder.componentColumns C) : dist x y ≤ 10 * D := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  45. lemma OAI.PlanarL1.Columns.Model.Point.radial_difference_le line 635

    Source documentation

    Changing to the fixed midheight costs at most one band width in any radial comparison. This also controls all zero-distance representatives.

    lemma radial_difference_le (o x y : M.Point J root) {H a : ℝ} (hH : H ∈ J)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2) :
        |dist o (x.withHeight H hH) - dist o (y.withHeight H hH)| ≤ dist x y + a := by
    …
  46. lemma OAI.PlanarL1.Columns.Model.Point.path_radial_bound line 654

    Source documentation

    A column visited by a short switching path has a nearby radial midpoint. The conclusion uses the actual path prefix, rather than a shortest path constrained to a radial cell.

    lemma path_radial_bound (o x y : M.Point J root) {H a : ℝ} (hH : H ∈ J)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2) (p : M.Path J x.column y.column)
        {i : Fin n} (hi : i ∈ p.word.support) :
        ∃ hr : (M.activeGraph J).Reachable root i,
          |dist o (⟨i, H, hH, hr⟩ : M.Point J root) - dist o (x.withHeight H hH)| ≤
            p.length x.height y.height + a := by
    …
  47. lemma OAI.PlanarL1.Columns.Model.Point.radial_cell_padding line 676

    Source documentation

    Deterministic padding in one actual radial layer. All representatives of all endpoints are covered because the lemma is stated on the pseudometric space of representatives.

    lemma radial_cell_padding (o x y : M.Point J root) {H a q D ρ : ℝ}
        (hH : H ∈ J) (ha : 0 ≤ a) (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.layer H hH q D)).ConnectedComponent)
        (hx : x.column ∈ ColumnOrder.componentColumns C)
        (hlow : q + ρ + 2 * a < dist o (x.withHeight H hH))
        (hupp : dist o (x.withHeight H hH) < q + D - ρ - 2 * a)
        (p : M.Path J x.column y.column) (hp : p.length x.height y.height ≤ ρ) :
        y.column ∈ ColumnOrder.componentColumns C := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  48. lemma OAI.PlanarL1.Columns.Model.Point.radial_ball_padding line 690
  49. def OAI.PlanarL1.Columns.Model.Point.frontier line 702

    Source documentation

    The literal full-column frontier of a column cell in the active graph.

    def frontier (C : Set (Fin n)) : Set (Fin n) :=
    …
  50. lemma OAI.PlanarL1.Columns.Model.Point.frontier_radial line 707

    Source documentation

    A frontier midpoint is within one width of a layer threshold. The neighbor cannot be in the same layer, since the cell is a component there.

    lemma frontier_radial (o z : M.Point J root) {H a q D : ℝ} (hH : H ∈ J)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.layer H hH q D)).ConnectedComponent)
        (hz : z.column ∈ frontier (M := M) (J := J) (ColumnOrder.componentColumns C)) :
    …

    Mentions: OAI.PlanarL1.Columns.Model.Point.frontier, OAI.PlanarL1.ColumnOrder.componentColumns

  51. lemma OAI.PlanarL1.Columns.Model.Point.radial_frontier_distance line 733

    Source documentation

    Exact strict avoidance of the frontier, the second assertion of geo:padding. The empty-frontier case is automatic, not assigned distance 0.

    lemma radial_frontier_distance (o x z : M.Point J root) {H a q D ρ : ℝ}
        (hH : H ∈ J) (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.layer H hH q D)).ConnectedComponent)
        (hlow : q + ρ + 2 * a < dist o (x.withHeight H hH))
        (hupp : dist o (x.withHeight H hH) < q + D - ρ - 2 * a)
        (hz : z.column ∈ frontier (M := M) (J := J) (ColumnOrder.componentColumns C)) :
    …

    Mentions: OAI.PlanarL1.Columns.Model.Point.frontier, OAI.PlanarL1.ColumnOrder.componentColumns

  52. def OAI.PlanarL1.Columns.Model.Point.columnMap line 748

    Source documentation

    Every fixed column is an isometric copy of its allowed height interval.

    def columnMap (i : Fin n) (hi : (M.activeGraph J).Reachable root i) : J → M.Point J root :=
    …
  53. lemma OAI.PlanarL1.Columns.Model.Point.columnMap_isometry line 751
  54. lemma OAI.PlanarL1.Columns.Model.Point.fullColumns_compact line 760

    Source documentation

    Compactness of any full-column subset in a compact band, including the literal radial cells and their frontiers. This argument works before taking the separation quotient and does not require a false Hausdorff assumption.

    lemma fullColumns_compact (hJ : IsCompact J) (C : Set (Fin n)) :
        IsCompact {x : M.Point J root | x.column ∈ C} := by
    …
  55. lemma OAI.PlanarL1.Columns.Model.Point.frontier_minimizer line 780

    Source documentation

    A continuous scalar frontier constraint attains its infimum whenever there is a frontier point. Used by the main raise-or-descend test.

    lemma frontier_minimizer (hJ : IsCompact J) (C : Set (Fin n))
        (s : M.Point J root → ℝ) (hs : Continuous s) (x : M.Point J root) (c : ℝ)
        (hne : ∃ z : M.Point J root, z.column ∈ frontier (M := M) (J := J) C) :
    …

    Mentions: OAI.PlanarL1.Columns.Model.Point.frontier

  56. lemma OAI.PlanarL1.Columns.Model.Point.exists_between line 796

    Source documentation

    The metric interpolation property of an actual attained shortest path. This is the geodesic fact used by the small-ball and descending-path arguments.

    lemma exists_between (hJ : IsClosed J) (hconv : Set.OrdConnected J)
        (x y : M.Point J root) {ℓ : ℝ} (hℓ : 0 ≤ ℓ) (hlen : ℓ ≤ dist x y) :
        ∃ z : M.Point J root, dist x z = ℓ ∧ dist z y = dist x y - ℓ := by
    …
  57. lemma OAI.PlanarL1.Columns.Model.Point.descent_along_shortest line 814

    Source documentation

    Every point on a shortest descending path retains the endpoint's deficit bound. This is main:ray-prefix, expressed by exact arclength distances.

    lemma descent_along_shortest {s : M.Point J root → ℝ} {ε : ℝ}
        (hs : ∀ u v, s u - s v ≤ dist u v) (x z v : M.Point J root)
        (hshort : dist x v + dist v z = dist x z)
        (hdrop : s z ≤ s x - dist x z + ε) :
        s v ≤ s x - dist x v + ε := by
    …
  58. def OAI.PlanarL1.Columns.Model.Point.ballColumns line 824

    Source documentation

    All representatives of the intrinsic closed ball, projected to columns. Using representatives includes columns identified by zero-length paths.

    def ballColumns (x : M.Point J root) (ρ : ℝ) : Set (Fin n) :=
    …
  59. lemma OAI.PlanarL1.Columns.Model.Point.mem_ballColumns line 827
  60. lemma OAI.PlanarL1.Columns.Model.Point.path_ballColumns line 830
  61. lemma OAI.PlanarL1.Columns.Model.Point.ballColumns_preconnected line 844

    Source documentation

    The projection of an actual closed ball is induced-connected. This is not an assumed graph property in the local interpolation argument.

    lemma ballColumns_preconnected (hJ : IsClosed J) (x : M.Point J root) (ρ : ℝ) :
        ((M.activeGraph J).induce (x.ballColumns ρ)).Preconnected := by
    …
  62. lemma OAI.PlanarL1.Columns.Model.Point.ballColumns_nonempty line 860
  63. lemma OAI.PlanarL1.Columns.Model.Point.ball_radial_spread line 865

    Source documentation

    The sharper 2ρ+a version of the source's 2ρ+2a radial spread.

    lemma ball_radial_spread (o x y z : M.Point J root) {H a ρ : ℝ} (hH : H ∈ J)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (hy : dist x y ≤ ρ) (hz : dist x z ≤ ρ) :
        |dist o (y.withHeight H hH) - dist o (z.withHeight H hH)| ≤ 2 * ρ + a := by
    …
  64. lemma OAI.PlanarL1.Columns.Model.Point.exit_superlevel_to line 877

    Source documentation

    A shortest path to any point outside a high component reaches an actual entrance within its total length. Unlike exit_superlevel, no radial decrease to the root is needed.

    lemma exit_superlevel_to (hJ : IsClosed J) (o x y : M.Point J root)
        {H t : ℝ} (hH : H ∈ J)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent)
        (hx : x.column ∈ ColumnOrder.componentColumns C)
        (hy : y.column ∉ ColumnOrder.componentColumns C) :
        ∃ z : M.Point J root, z.withHeight H hH ∈ o.entrances H hH t C ∧
          dist x z ≤ dist x y := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  65. lemma OAI.PlanarL1.Columns.Model.Point.near_component_portal line 905

    Source documentation

    Any point in a high component and within L of a point outside it is within L+200a of one of its two fixed entrance portals.

    lemma near_component_portal (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ha : 0 < a)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent)
        (hne : (o.entrances H hH t C).Nonempty) :
        ∃ p ∈ o.entrances H hH t C, ∃ q ∈ o.entrances H hH t C,
          ∀ x y : M.Point J root, x.column ∈ ColumnOrder.componentColumns C →
            y.column ∉ ColumnOrder.componentColumns C →
            dist x p ≤ dist x y + 200 * a ∨ dist x q ≤ dist x y + 200 * a := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  66. lemma OAI.PlanarL1.Columns.Model.Point.ball_radial_minimum line 925

    Source documentation

    The fixed-height radial profile attains its minimum among the finite set of columns represented in a nonempty closed ball.

    lemma ball_radial_minimum (o x : M.Point J root) {H ρ : ℝ} (hH : H ∈ J)
        (hρ : 0 ≤ ρ) :
        ∃ y : M.Point J root, dist x y ≤ ρ ∧
          ∀ z : M.Point J root, dist x z ≤ ρ →
            dist o (y.withHeight H hH) ≤ dist o (z.withHeight H hH) := by
    …
  67. lemma OAI.PlanarL1.Columns.Model.Point.ball_two_layers line 949

    Source documentation

    The exact geometric content of the one-chain small-ball argument: there are only two consecutive radial layer depths in a sufficiently small ball, and all its representatives lie in one node at the lower depth.

    lemma ball_two_layers (hJ : IsClosed J) (o x : M.Point J root)
        {H a ρ δ : ℝ} (hH : H ∈ J) (hρ : 0 ≤ ρ) (hδ : 0 < δ)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2) (hsmall : 2 * ρ + a < δ) :
        ∃ k : ℕ, ∃ y : M.Point J root,
          ∃ C : ((M.activeGraph J).induce (o.superlevel H hH (k * δ))).ConnectedComponent,
            dist x y ≤ ρ ∧ dist o (y.withHeight H hH) < (k + 1) * δ ∧
            (∀ z : M.Point J root, dist x z ≤ ρ →
              z.column ∈ ColumnOrder.componentColumns C ∧
              (k : ℝ) * δ ≤ dist o (z.withHeight H hH) ∧
              dist o (z.withHeight H hH) < (k + 2) * δ) := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  68. lemma OAI.PlanarL1.Columns.Model.Point.mem_zero_component line 986

    Source documentation

    At depth zero the single radial node contains every reachable column, including the chosen basepoint column.

    lemma mem_zero_component (o x : M.Point J root) {H : ℝ} (hH : H ∈ J)
        (C : ((M.activeGraph J).induce (o.superlevel H hH 0)).ConnectedComponent) :
        x.column ∈ ColumnOrder.componentColumns C := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  69. structure OAI.PlanarL1.Columns.Model.Point.PortalData line 999

    Source documentation

    Two fixed geometric portals, with all bounds required by the actual interpolation hierarchy. Repeated portals encode the one-portal case.

    structure PortalData (o : M.Point J root) (H : ℝ) (hH : H ∈ J) (a t : ℝ)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent) where
    …
  70. lemma OAI.PlanarL1.Columns.Model.Point.portalData_nonempty line 1017

    Source documentation

    The portal data are constructed from the proved geometry, including the root convention; they are not assumptions on the interpolation input.

    lemma portalData_nonempty (hJ : IsClosed J) (o : M.Point J root)
        {H a t : ℝ} (hH : H ∈ J) (ho : o.height = H) (ha : 0 < a)
        (hhalf : ∀ T ∈ J, |H - T| ≤ a / 2) (ht : t = 0 ∨ a / 2 < t)
        (C : ((M.activeGraph J).induce (o.superlevel H hH t)).ConnectedComponent) :
        Nonempty (o.PortalData H hH a t C) := by
    …
  71. lemma OAI.PlanarL1.Columns.Model.Point.PortalData.near_of_radial line 1050

    Source documentation

    Layer points and points only slightly beyond its top are close to a fixed portal. The radial allowance is kept explicit for child portals.

    lemma near_of_radial (K : o.PortalData H hH a t C)
        {δ e : ℝ} (x : M.Point J root) (hx : x.column ∈ ColumnOrder.componentColumns C)
        (hr : dist o x ≤ t + δ + e) :
        min (dist x K.left) (dist x K.right) ≤ δ + e + 201 * a := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns

  72. lemma OAI.PlanarL1.Columns.Model.Point.PortalData.near_layer line 1056
  73. lemma OAI.PlanarL1.Columns.Model.Point.PortalData.near_exit line 1069

    Source documentation

    A near-exit point is in the equality collar of these same portals; there is no resampling or reselecting a different portal pair.

    lemma near_exit (K : o.PortalData H hH a t C) (hJ : IsClosed J)
        (x y : M.Point J root) (hx : x.column ∈ ColumnOrder.componentColumns C)
        (hy : y.column ∉ ColumnOrder.componentColumns C) :
        min (dist x K.left) (dist x K.right) ≤ dist x y + 200 * a := by
    …

    Mentions: OAI.PlanarL1.ColumnOrder.componentColumns