Erdős problem 1036
Let be a graph on vertices which does not contain a trivial (empty or complete) graph on more than vertices. Must contain at least many induced subgraphs which are not pairwise isomorphic?
Sources
FormalConjectures/ErdosProblems/
1036.lean
Retained formal statement
Let be a graph on vertices which does not contain a trivial (empty or complete) graph on more than vertices. Must contain at least many induced subgraphs which are not pairwise isomorphic?
This is true, and was proved by Shelah [Sh98].
True ↔ ∀ (c : ℝ), 0 < c → ∃ δ, 0 < δ ∧ ∀ᶠ (n : ℕ) in Filter.atTop, ∀ (G : SimpleGraph (Fin n)), ↑G.cliqueNum ≤ c * Real.log ↑n → ↑G.indepNum ≤ c * Real.log ↑n → Erdos1036.HasManyNonIsomorphicInducedSubgraphs G (2 ^ (δ * ↑n))