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Source labels openChecked July 26, 2026

Erdős ProblemsNumber theory

Erdős Problem 332

Let ANA\subseteq \mathbb{N} and D(A)D(A) be the set of those numbers which occur infinitely often as a1a2a_1 - a_2 with a1,a2Aa_1, a_2\in A. What conditions on AA are sufficient to ensure D(A)D(A) has bounded gaps?

Mathematical statement

Let ANA\subseteq \mathbb{N} and D(A)D(A) be the set of those numbers which occur infinitely often as a1a2a_1 - a_2 with a1,a2Aa_1, a_2\in A. What conditions on AA are sufficient to ensure D(A)D(A) has bounded gaps?

This is formalised here using the answer(sorry) mechanism. In order to solve this problem one has to provide what the sufficient conditions are, and proof that they imply the desired condition. If the condition is a solution to the problem is up to human judgement.

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_332

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_332 (A : Set ) : (answer(sorry) : Set   Prop) A  HasBoundedGaps (D_A A) := 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