OAI/Geometry/HyperbolicGroups/SubpairingTree.lean
3 declarations, 0 contain sorry, 0 declared as axioms
- lemma
OAI.HyperbolicObstruction.PictureSwitch.card_quotient_top_oneline 23 - theorem
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.subpairing_isTreeline 39Source documentation
A literal one-boundary spanning subpairing of a connected genus-zero map is a tree on the actual rotation vertices. This also rules out retained loops and duplicate edges: the edge-count bound and connectivity force equality.
theorem subpairing_isTree (hG : M.GenusZero) (q : Perm D) (hsub : ∀ x, q x = x ∨ q x = M.edge x) (hspan : SameCycle.setoid M.vertex ⊔ SameCycle.setoid q = ⊤) (hboundary : cycles (M.vertex*q) = 1) : (M.subpairingGraph q (M.subpairing_sq q hsub)).IsTree := by … - theorem
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.connected_tree_cotreeline 67Source documentation
Complementary primal and dual TREE graphs, obtained from the real side-pairing and exact genus-zero equation. No abstract drawing or tree interface has been substituted for the rotation system.
theorem connected_tree_cotree (hG : M.GenusZero) (hconn : M.components = ⊤) : ∃ q : Perm D, ∃ hq : ∀ x, q x = x ∨ q x = M.edge x, (M.subpairingGraph q (M.subpairing_sq q hq)).IsTree ∧ (M.dual.subpairingGraph (q*M.edge) (M.subpairing_sq (q*M.edge) (M.complement_subpairing q hq))).IsTree := by …