OAI/Combinatorics/Ramsey/CycleClique/Construction/Size.lean
8 declarations, 0 contain sorry, 0 declared as axioms
The manuscript's size test, conditional on Chvátal–Erdős
An induced vertex set larger than both k and twice the clique number
has an independent triple in a graph with no exact (k + 1)-cycle.
The only published hypothesis is CEAlphaTwo; the disconnected and
cutvertex cases and exact-cycle shortening are proved here.
- structure
OAI.CycleClique.Construction.TwoCliquePartitionline 16 - theorem
OAI.CycleClique.Construction.two_clique_partitionline 26 - theorem
OAI.CycleClique.Construction.TwoCliquePartition.cardline 67 - theorem
OAI.CycleClique.Construction.connected_of_no_independent_tripleline 73 - theorem
OAI.CycleClique.Construction.joined_clique_cardline 85 - theorem
OAI.CycleClique.Construction.deletion_connected_of_no_independent_tripleline 108 - theorem
OAI.CycleClique.Construction.size_test_graphline 151Source documentation
The size test on the whole finite graph, conditional only on the published Chvátal–Erdős input.
theorem size_test_graph (hCE : CEAlphaTwo) {V : Type} [Fintype V] {G : SimpleGraph V} {k t : ℕ} (hk : 5 ≤ k) (ht : 1 ≤ t) (hcycle : ¬ HasCycle G (k + 1)) (hclique : G.cliqueNum ≤ t) (hcard : max k (2 * t) < Fintype.card V) : HasIndependent G 3 := by …Mentions: OAI.CycleClique.Construction.CEAlphaTwo, OAI.CycleClique.Construction.HasCycle, OAI.CycleClique.Construction.HasIndependent
- theorem
OAI.CycleClique.Construction.size_testline 166Source documentation
Manuscript Lemma
size:test: every sufficiently large vertex set contains three independent vertices.theorem size_test (hCE : CEAlphaTwo) {V : Type} [Fintype V] {G : SimpleGraph V} {k t : ℕ} (hk : 5 ≤ k) (ht : 1 ≤ t) (hcycle : ¬ HasCycle G (k + 1)) (hclique : G.cliqueNum ≤ t) (Y : Finset V) (hY : max k (2 * t) < Y.card) : HasIndependent (G.induce (Y : Set V)) 3 := by …Mentions: OAI.CycleClique.Construction.CEAlphaTwo, OAI.CycleClique.Construction.HasCycle, OAI.CycleClique.Construction.HasIndependent