OAI/Combinatorics/Ramsey/CycleClique/Construction/TriangleFacts.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

The exceptional triangle Ramsey number

The elementary six-vertex argument and the complementary pentagons prove R(C₃,K₃) = 6, the exceptional clause of the manuscript's main theorem.

  1. theorem OAI.CycleClique.Construction.hasCycle_three_of_edges line 15
  2. theorem OAI.CycleClique.Construction.hasIndependent_three_of_distinct_nonadjacent line 26
  3. theorem OAI.CycleClique.Construction.triangle_upper line 40

    Source documentation

    Every graph on six vertices has a triangle or three independent vertices.

    theorem triangle_upper : RamseyProperty 3 3 6 := by
    …

    Mentions: OAI.CycleClique.Construction.RamseyProperty

  4. def OAI.CycleClique.Construction.pentagon line 78

    Source documentation

    The pentagon coloring: red edges have cyclic difference one.

    def pentagon : SimpleGraph (Fin 5) where
    …
  5. instance OAI.CycleClique.Construction.(instance at line 83) line 83
  6. theorem OAI.CycleClique.Construction.pentagon_no_triangle line 85
  7. theorem OAI.CycleClique.Construction.pentagon_no_independent_triple line 89
  8. theorem OAI.CycleClique.Construction.triangle_lower line 96

    Source documentation

    Five vertices do not force a monochromatic triangle.

    theorem triangle_lower : ¬ RamseyProperty 3 3 5 := by
    …

    Mentions: OAI.CycleClique.Construction.RamseyProperty