OAI/GroupTheory/Kervaire/RelatorRigidity.lean

GitHub source file

23 declarations, 0 contain sorry, 0 declared as axioms

  1. def OAI.KervaireRibbon.corner line 15

    Source documentation

    The coefficient on the corner immediately following a dart.

    def corner (σ θ : Perm D) (u : D → A) (d : D) : A := u (θ d) * (u (σ d))⁻¹
    …
  2. lemma OAI.KervaireRibbon.corner_gauge line 18
  3. lemma OAI.KervaireRibbon.align_distinct_faces line 29

    Source documentation

    Independent face gauges can align two vertices precisely when the two relevant faces are distinct.

    lemma align_distinct_faces (σ θ : Perm D) (hθ : ∀ d, θ (θ d) = d)
        (u : D → A) {p q : D} (hpq : ¬ (σ*θ).SameCycle p q) :
        ∃ v : D → A, corner σ θ v = corner σ θ u ∧ v q = v p := by
    …

    Mentions: OAI.KervaireRibbon.corner

  4. lemma OAI.KervaireRibbon.planar_symm line 40
  5. lemma OAI.KervaireRibbon.cap_vertex line 50
  6. lemma OAI.KervaireRibbon.cap_vertex_other line 74
  7. lemma OAI.KervaireRibbon.planar_cap line 87
  8. lemma OAI.KervaireRibbon.suppress_u line 111
  9. lemma OAI.KervaireRibbon.corner_cap line 132
  10. lemma OAI.KervaireRibbon.components_map line 155
  11. lemma OAI.KervaireRibbon.components_equiv line 172
  12. lemma OAI.KervaireRibbon.classes_components_equiv line 182
  13. lemma OAI.KervaireRibbon.planar_equiv line 187
  14. lemma OAI.KervaireRibbon.connected_equiv line 195
  15. lemma OAI.KervaireRibbon.sum_eq_zero_of_opposite line 211
  16. lemma OAI.KervaireRibbon.vertex_balance line 216
  17. lemma OAI.KervaireRibbon.balanced_vertices line 229

    Source documentation

    Exact positive/negative disk coordinates, derived from the sign conservation of the bands rather than postulated as a balancing hypothesis.

    lemma balanced_vertices (ε : V → ℤ) (hε : ∀ v, ε v = 1 ∨ ε v = -1)
        (hzero : (∑ v, ε v) = 0) :
        ∃ q : ({v // ε v = 1} ⊕ {v // ε v = 1}) ≃ V,
          (∀ k, ε (q (Sum.inl k)) = 1) ∧ (∀ k, ε (q (Sum.inr k)) = -1) := by
    …
  18. def OAI.KervaireRibbon.vertexNext line 262
  19. def OAI.KervaireRibbon.vertexCorner line 264
  20. theorem OAI.KervaireRibbon.relator_corner_rigidity line 267
  21. structure OAI.KervaireRibbon.DiskAtlas line 348

    Source documentation

    Disjoint relator disks in a larger ribbon diagram. The other darts may belong to an outside word or be isolated markers from previous cancellations.

    structure DiskAtlas (ρ : Perm I) (a : I → A) (s : I → ℤ)
        (σ : Perm D) (t : D → ℤ) where
    …
  22. lemma OAI.KervaireRibbon.disk_sameCycle line 359

    Source documentation

    Every dart on a word disk lies in the same ribbon component as its chosen representative.

    lemma disk_sameCycle (ρ : Perm I) (hρ : ∀ i j, ρ.SameCycle i j)
        (a : I → A) (s : I → ℤ) (σ : Perm D) (t : D → ℤ)
        (b : DiskAtlas (V := V) ρ a s σ t) (v : V) (i j : I) :
    …

    Mentions: OAI.KervaireRibbon.DiskAtlas

  23. theorem OAI.KervaireRibbon.atlas_component_rigidity line 388

    Source documentation

    Restricting whole relator disks to one component retains the literal word coordinates, including the actual reversed corners of negative disks.

    theorem atlas_component_rigidity [Nonempty I]
        (ρ : Perm I) (hρ : ∀ i j, ρ.SameCycle i j) (a : I → A)
        (s : I → ℤ) (hs : ∀ i, s i = 1 ∨ s i = -1) (hsum : (∑ i, s i) = 1 ∨ (∑ i, s i) = -1)
        (σ θ : Perm D) (hθ : ∀ d, θ (θ d) = d) (t : D → ℤ)
        (ht : ∀ d, t (θ d) = -t d) (hp : planar σ θ)
        (b : DiskAtlas (V := V) ρ a s σ t) (u : D → A) (p : D)
    …

    Mentions: OAI.KervaireRibbon.planar, OAI.KervaireRibbon.DiskAtlas