OAI/Geometry/HyperbolicGroups/PictureCotreeTree.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

  1. lemma OAI.HyperbolicObstruction.PictureSwitch.PictureMap.complement_boundary_eq line 22
  2. theorem OAI.HyperbolicObstruction.PictureSwitch.PictureMap.cotree_isTree line 37

    Source documentation

    The complement of ANY literal spanning-tree subpairing is a dual tree, not just the particular Kruskal forest supplied by tree_cotree. This is needed when the primal tree is chosen for a radius bound.

    theorem cotree_isTree (hG : M.GenusZero)
        (hspan : SameCycle.setoid M.vertex ⊔ SameCycle.setoid q = ⊤)
        (hboundary : cycles (M.vertex*q) = 1) : (M.cotreeGraph q hq).IsTree := by
    …

    Mentions: OAI.HyperbolicObstruction.PictureSwitch.cycles