OAI/Combinatorics/Ramsey/CycleClique/Construction/EndpointFullAttachment.lean
3 declarations, 0 contain sorry, 0 declared as axioms
Rotating from a second attachment extends the prefix exclusion to every endpoint.
- theorem
OAI.CycleClique.Construction.spanningPath_first_tail_lastline 8 - theorem
OAI.CycleClique.Construction.endpoint_attachment_of_prefix_preservedline 43 - theorem
OAI.CycleClique.Construction.full_endpoint_attachmentline 75Source documentation
Every endpoint has no neighbour outside the endpoint clique other than the one attachment vertex.
theorem full_endpoint_attachment {V : Type*} [Fintype V] {G : SimpleGraph V} {x : V} {W : Finset V} {r : ℕ} {f : Fin (r + 1) → V} (hf : IsSpanningPath G x W f) (t : Fin r) (hfinal : ∀ i : Fin (r + 1), f i ∈ pathEnds G x W r ↔ t.val < i.val) (hclique : G.IsClique (pathEnds G x W r : Set V)) (hneighbors : ∀ e ∈ pathEnds G x W r, ∀ v, G.Adj e v → v ∈ W) (hsecond : ∃ w ∈ pathEnds G x W r, w ≠ f t.succ ∧ G.Adj (f t.castSucc) w) : ∀ w ∈ pathEnds G x W r, ∀ v, G.Adj w v → v ∈ pathEnds G x W r ∨ v = f t.castSucc := by …Mentions: OAI.CycleClique.Construction.IsSpanningPath, OAI.CycleClique.Construction.pathEnds