Erdős Problem 501
For every let be a bounded set with outer measure . Must there exist an infinite independent set, that is, some infinite such that for all ?
Mathematical statement
For every let be a bounded set with outer measure . Must there exist an infinite independent set, that is, some infinite such that for all ?
If the sets are closed and have measure , then must there exist an independent set of size ?
Known results: Erdős–Hajnal [ErHa60] proved the existence of arbitrarily large finite independent sets. Hechler [He72] showed the answer is no assuming the continuum hypothesis.
Statement source: Erdős Problems statement material
Statement terms: Source-specific
Source-specific terms. Therefore does not assert reuse rights beyond attributed display.
Statement artifacts, not proofs
These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.
Pinned Lean formulation 1
erdos_501
theorem erdos_501 : answer(sorry) ↔ ∀ (A : ℝ → Set ℝ), (∀ x, Bornology.IsBounded (A x)) → (∀ x, volume.toOuterMeasure (A x) < 1) → ∃ X : Set ℝ, X.Infinite ∧ X.Pairwise (fun x y => x ∉ A y) := by sorry- Statement source
- Formal Conjectures
- Lean version
- v4.27.0
- Placeholder
- Present; no proof artifact
- Source evidence
- Pinned source index
- Fidelity review
- Community formulation
References