OAI/Geometry/HyperbolicGroups/PicturePlanarSeparator.lean
2 declarations, 0 contain sorry, 0 declared as axioms
- theorem
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.planar_component_separatorline 23Source documentation
Literal genus-zero planar separator, independent of face degrees, vertex degrees, all parallel copies, and the specified vertex carrier.
theorem planar_component_separator (hG : M.GenusZero) (hc : M.underlyingGraph.Connected) (U : Finset M.GraphVertex) : ∃ S : Finset M.GraphVertex, S ⊆ U ∧ S.card ≤ 11*Nat.sqrt U.card ∧ ∀ W : Finset M.GraphVertex, W ⊆ U → Disjoint W S → (M.underlyingGraph.induce (W : Set M.GraphVertex)).Preconnected → 2*W.card ≤ U.card := by … - theorem
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.planar_balanced_separatorsline 35Source documentation
A connected genus-zero rotation system has balanced separators.
theorem planar_balanced_separators (hG : M.GenusZero) (hc : M.underlyingGraph.Connected) : HasBalancedSeparators M.underlyingGraph 11 := …