Treglown's equitable acyclic colouring conjecture
Treglown conjectured, in a complementary form, that for every positive integer every digraph with for all has an equitable acyclic -colouring. This implies the acyclic colouring versions of the Hajnal-Szemeredi theorem for digraphs proved by Czygrinow, DeBiasio, Kierstead and Molla, which in turn imply the original Hajnal-Szemeredi theorem for graphs. Proved: a short reduction shows the conjecture follows directly from the original Hajnal-Szemeredi theorem, and a modification of it gives a polynomial-time algorithm for finding such a colouring.
- Result
- Proved(see note)
- Status
- Resolved
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Graph theory
- Posed by
- Andrew Treglown
- Year posed
- —
- Years open
- —
- Solved
- 2026-08-12
- Model
- ChatGPT 5.6 Sol
- Vendor
- OpenAI
- Collaborators
- Louis DeBiasio, Hal Kierstead
- Verification
- Unreviewed
- Publication
- Preprint
- Significance
- 15 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
The honest reading, which the paper gives itself: the reduction is implicit in earlier work of Aboulker, Oijid, Petit, Rocton and Simon, and the model itself surfaced that reference when asked about originality. So this establishes the conjecture and supplies a polynomial-time algorithm, while the underlying idea is a rediscovery rather than a first. It is a striking record of a model producing an argument and then correcting the novelty claim made for it.
What the AI did
The acknowledgements describe the model producing the argument and then correcting its own novelty claim: "The reduction given in this paper arose during a discussion between the first author and ChatGPT 5.6 Sol attempting to locate the bottleneck in extending the results of [3] to prove Conjecture 1.2. Instead of locating the bottleneck, the chatbot gave a clever proof which shows that Conjecture 1.2 reduces to the original Hajnal-Szemeredi theorem. After further discussion about the originality of this idea, the chatbot identified earlier work of Aboulker, Oijid, Petit, Rocton, and Simon" in which the reduction is implicit. The central idea of the paper came from the model, which places it at the discovered tier, with the caveat about priority recorded in the result note.
Verification
arXiv preprint, one day old at cataloguing, not peer-reviewed. The authors are established researchers in the area and the paper is short, resting on a reduction to a classical theorem rather than new machinery, but this site has not verified it and no independent commentary exists yet.