OAI/Geometry/HyperbolicGroups/PictureTriangulationEuler.lean
13 declarations, 0 contain sorry, 0 declared as axioms
- lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.star_vertex_liftline 22 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.star_center_liftline 33 - def
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.starVertexClassline 40Source documentation
The new vertices are exactly the old vertices plus the separate centers of the old faces. This retains all original vertex identifications.
def starVertexClass : StarDart D → M.GraphVertex ⊕ Quotient (SameCycle.setoid M.face) | .inl x => .inl (M.vertexClass x) | .inr (.inl x) => .inl (M.vertexClass (M.face x)) | .inr (.inr x) => .inr (Quotient.mk _ x) omit [DecidableEq D] [Fintype D] in
Mentions: OAI.HyperbolicObstruction.PictureSwitch.PictureMap.StarDart
- lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.starVertexClass_stepline 46 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.star_vertex_cycleline 57 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.starVertexClass_surjectiveline 88 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.triangulation_vertex_cyclesline 96 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.star_components_liftline 102 - def
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.starComponentline 114 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.star_componentsline 118 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.triangulation_components_cardline 136 - lemma
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.triangulation_eulerline 143 - theorem
OAI.HyperbolicObstruction.PictureSwitch.PictureMap.triangulation_genusZeroline 153Source documentation
Literal face starring preserves genus zero and connected-component count; its dual is therefore a genuine degree-three genus-zero ribbon graph.
theorem triangulation_genusZero (h : M.GenusZero) : M.triangulation.GenusZero := by …