All open problems
Source labels openChecked July 26, 2026
Erdős Problem 125: Zero Lower Positive Upper Density
Case 2: Does have zero lower density, but positive upper density?
Mathematical statement
Case 2: Does have zero lower density, but positive upper density?
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_125.variants.zero_lower_positive_upper_density
Complete statement target, proof intentionally absentLean 4
theorem erdos_125.variants.zero_lower_positive_upper_density : answer(sorry) ↔ (A + B).lowerDensity = 0 ∧ 0 < (A + B).upperDensity := 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