Erdős Problem a Daythe open tracker

Erdős Problem #172

OPENdatabase updated 2025-08-31

No proof or disproof is known, and it isn't known whether a finite computation could settle it.

What the community database records, not our verdict. erdosproblems.com no longer shows statuses (why).

Is it true that in any finite colouring of \(\mathbb{N}\) there exist arbitrarily large finite \(A\) such that all sums and products of distinct elements in \(A\) are the same colour?
Statement as formalized in Formal Conjectures (Google DeepMind, Apache-2.0) · their label: research solved. The authoritative wording is on erdosproblems.com/172.
Newer public claim (6 Oct 2026): OpenAI's internal-model release claims, for this problem, Hindman's sums-and-products conjecture — family 164 at github.com/openai/math, no Lean in the release — but a third-party Lean 4 proof following the paper (Yao Xu, cadamcat/hindman-sums-products-lean4) exists and was kernel-replayed on our machine on 11 Oct 2026; see our /day entry. Bloom calls these claims, not endorsements; anything on this page that says the question is open was written before that release and has not re-checked it.
Prizenone
Topicsadditive combinatorics, ramsey theory
Statement in LeanFormal Conjectures
Solution in Leanno
Original pageerdosproblems.com/172
FULL WRITE-UP BY THIS SITE · OCT 11, 2026

Read our full write-up →

Hindman asked whether every finite colouring of the positive integers contains arbitrarily large finite sets whose nonempty subset sums and subset products all share one colour. Alweiss proved it over the rationals; over the integers it was open until OpenAI's 23 September 2026 paper claimed it. We read all 70 pages, checked every cited theorem against its current source, ran a hostile machine referee over the whole chain, and found that a third party (Yao Xu) has since written a 6-megabyte Lean 4 proof following the paper, sorry-free, with OpenAI's own library supplying the hardest half. Four sectioned hostile referee seats read the paper as written and found no gap — every cited theorem says what the paper says it says — and our own from-source kernel replay of the Lean proof printed the three standard axioms. The problem is closed.

CLOSED