OAI/Combinatorics/Ramsey/CycleClique/Construction/LowerBound.lean
7 declarations, 0 contain sorry, 0 declared as axioms
The disjoint-clique lower bound
The red graph consists of a disjoint complete graphs of order k.
A red cycle stays within one block, while an independent set uses at most
one vertex from each block. This is the lower-bound construction in the
proof of Theorem 1 of Cycle--clique Ramsey numbers.
- def
OAI.CycleClique.Construction.blockGraphline 17Source documentation
Disjoint red cliques: the first coordinate records the block.
def blockGraph (a k : ℕ) : SimpleGraph (Fin a × Fin k) where …
- theorem
OAI.CycleClique.Construction.blockGraph_adjline 22 - theorem
OAI.CycleClique.Construction.cycleNext_castSuccline 25 - theorem
OAI.CycleClique.Construction.blockGraph_cycle_boundline 31Source documentation
Every red cycle in the disjoint-clique construction lies in a single block.
theorem blockGraph_cycle_bound {a k m : ℕ} (hm : 0 < m) (h : HasCycle (blockGraph a k) m) : m ≤ k := by …Mentions: OAI.CycleClique.Construction.HasCycle, OAI.CycleClique.Construction.blockGraph
- theorem
OAI.CycleClique.Construction.blockGraph_independent_boundline 50Source documentation
An independent set uses at most one vertex in every block.
theorem blockGraph_independent_bound {a k n : ℕ} (h : HasIndependent (blockGraph a k) n) : n ≤ a := by …Mentions: OAI.CycleClique.Construction.HasIndependent, OAI.CycleClique.Construction.blockGraph
- theorem
OAI.CycleClique.Construction.blockGraph_not_ramseyline 60Source documentation
The lower-bound coloring on a linearly labelled set of
k * avertices.theorem blockGraph_not_ramsey {a k m n : ℕ} (hkm : k < m) (han : a < n) : ¬ RamseyProperty m n (k * a) := by … - theorem
OAI.CycleClique.Construction.cycle_clique_lower_boundline 77Source documentation
The sharp lower bound in the manuscript's main parameter range.
theorem cycle_clique_lower_bound {m n : ℕ} (hm : 3 ≤ m) (hn : 3 ≤ n) : ¬ RamseyProperty m n ((m - 1) * (n - 1)) := by …