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Source labels openChecked July 26, 2026

Erdős ProblemsCombinatorics

Erdős Problem 340: Sub Has Pos Density

Erdős and Graham [ErGr80] also asked about the difference set AAA - A and whether this has positive density.

Mathematical statement

Erdős and Graham [ErGr80] also asked about the difference set AAA - A and whether this has positive density.

[ErGr80] Erdős, P. and Graham, R., Old and new problems and results in combinatorial number theory. Monographies de L'Enseignement Mathematique (1980).

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_340.variants.sub_hasPosDensity

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_340.variants.sub_hasPosDensity :    Set.HasPosDensity (Set.range greedySidon - Set.range greedySidon) := 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