OAI/Geometry/HyperbolicGroups/PathLocalToGlobal.lean
3 declarations, 0 contain sorry, 0 declared as axioms
A finite-partition local-to-global principle for homotopy classes of actual continuous paths. This will convert open-star control into edge generation.
- abbrev
OAI.HyperbolicObstruction.PathLocalToGlobal.Qline 13 - lemma
OAI.HyperbolicObstruction.PathLocalToGlobal.castline 16 - theorem
OAI.HyperbolicObstruction.PathLocalToGlobal.of_open_coverline 22Source documentation
No subdivision or simplicial approximation assumption is made: the partition is obtained from compactness of the actual unit interval.
theorem of_open_cover {ι : Type*} (U : ι → Set X) (hU : ∀ i, IsOpen (U i)) (cover : ∀ x, ∃ i, x ∈ U i) (hrefl : ∀ x, R x x (.refl x)) (htrans : ∀ {x y z} {p : Q x y} {q : Q y z}, R x y p → R y z q → R x z (p.trans q)) (hlocal : ∀ i {x y} (p : Path x y), (∀ t, p t ∈ U i) → R x y (.mk p)) {x y : X} (p : Path x y) : R x y (.mk p) := by …