# Erdős Problem 520

A statement in qed.bot, the register of claims of AI work in mathematics. The register grades the evidence attached to each claim; it never rules on whether a proof is correct.

- Identifier: erdos:520
- Collection: Erdős
- Page: https://qed.bot/s/erdos-520
- Formal record: solved; at its source: open
- Machine-checked: no independent check has verified it
- Fidelity F2: The statement corpus cites this proof against its own statement.
- Source: https://www.erdosproblems.com/520

## AI claims

No AI contribution is recorded against this statement.

## Claimed on erdosproblems.com

Proof claims posted on erdosproblems.com, which says that listing a claim is no guarantee of proof correctness. Nobody has examined them, and none counts in the register's totals.

- Sigurd William Rachlew Høystad, using GPT 5.6 Sol Pro, Fable 5: a full proof claimed, 4 Aug 2026. Autonomy A?, evidence V0. https://www.erdosproblems.com/forum/thread/520/proof-claims#proof-claim-183
- Samuel Korsky, using GPT 5.6-Pro: a full proof claimed, 29 Jul 2026. Autonomy A?, evidence V0. https://www.erdosproblems.com/forum/thread/520/proof-claims#proof-claim-164

## Formal statements

- FormalConjectures/ErdosProblems/520.lean, https://github.com/google-deepmind/formal-conjectures/blob/main/FormalConjectures/ErdosProblems/520.lean

Cite as: qed.bot, "Erdős Problem 520", https://qed.bot/s/erdos-520, as of 30 Sep 2026. The register's data is published under CC BY 4.0: https://creativecommons.org/licenses/by/4.0/