Erdős problem 70
Erdős Problem 70: Let be the cardinality of the continuum, let be a countable ordinal, and let . Is it true that ?
Sources
FormalConjectures/ErdosProblems/
70.lean
Retained formal statement
Erdős Problem 70: Let be the cardinality of the continuum, let be a countable ordinal, and let . Is it true that ?
Note: The cases are trivially true (see omega_three), so the genuine content of the conjecture begins at .
True ↔ ∀ (β : Ordinal.{0}) (n : ℕ), β.card ≤ Cardinal.aleph0 → 2 ≤ n → Erdos70.OrdinalCardinalRamsey3 Cardinal.continuum.ord β ↑nOpenStatement only, no proof