import Mathlib import OAI.Geometry.Cannon.PlaneTopology.HomeoPlane import OAI.Geometry.Cannon.Boundary.BoundaryUniformComplementGraph import OAI.Geometry.Cannon.Boundary.BoundaryUniformConnectedComplement import OAI.Geometry.Cannon.PlaneTopology.ChartTameFaceCount import OAI.Geometry.Cannon.PlaneTopology.BoundaryBallCover import OAI.Geometry.Cannon.PlaneTopology.InteriorRadiusControl import OAI.Geometry.Cannon.Boundary.BoundaryUniformRingPacking import OAI.Geometry.Cannon.Uniformization.BoundaryUniformizationInputs import OAI.Geometry.Cannon.Conformal.QuasiMobius import OAI.Geometry.Cannon.Conformal.PlaneWeakQSBounded import OAI.Geometry.Cannon.Actions.BoundaryAction namespace OAI /-! A group with a hyperbolic Cayley graph and spherical boundary admits a proper, cocompact action on hyperbolic three-space with finite kernel. -/ section noncomputable section namespace CannonRelease universe u theorem cannon (G : Type u) [Group G] [TopologicalSpace G] [DiscreteTopology G] (D : CayleyData G) (hthin : D.ThinTriangles) (hsphere : Nonempty (Boundary D ≃ₜ SphereTwo)) : ∃ ρ : G →* H3Isom, ProperAction ρ ∧ CocompactAction ρ ∧ (ρ.ker : Set G).Finite := by obtain ⟨δ,hδ⟩ := hthin obtain ⟨φ⟩ := hsphere let _ := visualMetricSpace D hδ obtain ⟨ψ,hψ⟩ := boundary_quasiMobius_uniformizer D hδ φ exact boundary_uniformized_action D hδ ψ hψ end CannonRelease end end end OAI