Erdős problem 579
Let . If is sufficiently large and is a graph on vertices with no (the octahedron) and at least edges, must contain an independent set of size ?
Sources
FormalConjectures/ErdosProblems/
579.lean
Retained formal statement
The partial result of Erdős, Hajnal, Sós, and Szemerédi [EHSS83]: the statement of erdos_579 holds whenever the edge-density coefficient exceeds . That is, for every there is a such that for all sufficiently large , every -free graph on vertices with at least edges has an independent set of size at least .
∀ (δ : ℝ), 1 / 8 < δ → ∃ c, 0 < c ∧ ∀ᶠ (n : ℕ) in Filter.atTop, ∀ (G : SimpleGraph (Fin n)), Erdos579.octahedron.Free G → δ * ↑n ^ 2 ≤ ↑G.edgeFinset.card → c * ↑n ≤ ↑G.indepNumSolvedStatement only, no proof