Erdős problem 1167
Erdős Problem 1167. Let be finite, , and be an infinite cardinal. Let be cardinals for all . Is it true that implies Here means cardinal addition, so that if is infinite.
Sources
FormalConjectures/ErdosProblems/
1167.lean
Retained formal statement
The unrestricted version of Erdős Problem 1167 (without the condition from the original Erdős–Hajnal list) is false. Taking , , : the premise holds since , but the conclusion fails since .
¬∀ (r : ℕ), 2 ≤ r → ∀ (lam : Cardinal.{u}), Cardinal.aleph0 ≤ lam → ∀ (γ : Ordinal.{u}) (κ : γ.ToType → Cardinal.{u}), (Combinatorics.cardinalPartitionRel (2 ^ lam) (r + 1) γ fun α => κ α + 1) → Combinatorics.cardinalPartitionRel lam r γ κTestStatement only, no proof