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Source labels openChecked July 26, 2026

WikipediaNumber theory

Solitary Numbers

Existence of an infinite club.* A club is an abundancy equivalence class, i.e. the set of all positive integers friendly with a given nn. It is unknown whether any club is infinite.

Mathematical statement

Existence of an infinite club.* A club is an abundancy equivalence class, i.e. the set of all positive integers friendly with a given nn. It is unknown whether any club is infinite.

Statement source: Wikipedia statement material

Statement terms: CC-BY-SA-4.0

Attributed source material. Reuse must follow the linked attribution and share-alike terms.

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

infinite_club_exists

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem infinite_club_exists :    answer(sorry)   n, 0 < n  {m :  | Friendly m n}.Infinite := 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