OAI/Geometry/HyperbolicGroups/OneFaceFilling.lean
1 declarations, 0 contain sorry, 0 declared as axioms
- theorem
OAI.HyperbolicObstruction.WordPictures.WordPicture.one_face_fillingline 17Source documentation
Base case of planar extraction, proved from the combinatorial Euler definition: a genus-zero picture with no interior darts has a zero-area word filling. It is NOT postulated as a property of a picture.
theorem one_face_filling {w : Word A} (P : WordPicture R w) (hall : ∀ x, x ∈ P.outside) : Homotopy R w [] 0 := by …Mentions: OAI.HyperbolicObstruction.WordPictures.Word, OAI.HyperbolicObstruction.WordPictures.WordPicture, OAI.HyperbolicObstruction.WordPictures.Homotopy