Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
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Claim. For a fixed integer , consider the graphs in which every induced subgraph has, outside every prescribed clique, a vertex whose neighborhood becomes a clique after deleting at most vertices; the graphs with are exactly the chordal graphs. Obinna Okechukwu, Clique partitions and bounded simplicial defect, arXiv:2609.20871 (24 pages, math.CO, posted 15 September 2026, the claim's date), asserts that for each fixed the largest clique partition number at every sufficiently large order is , determines all graphs attaining it, and shows that the same expression bounds the clique partition number up to an additive constant depending only on at every order. For this gives, as the abstract states, that every chordal graph has clique partition number at most , answering the question of Erdős, Ordman and Zalcstein that is Problem 81 with yes. The abstract describes the method as signed fractional localization combined with an edge-disjoint triangle construction, needing only a qualitative fractional-packing approximation, and adds structural stability for sublinear defect and a finite-order theorem for integer signed clique functionals. This record rests on the arXiv abstract (as of 2026-10-07); this corpus has not checked the paper's proofs. Traverso's Paper IV cites the paper's Corollary 1.2 as obtaining the additive bound and eventual maximum for chordal graphs as a special case and its Theorem 1.1 for the extremal family.
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Standing. Claimed: an arXiv preprint with no refereed version, no formalization and no outside review known to this corpus. The author announced it in a comment of 21 September 2026 on the site's claim of Morluto, Luo, Huang and Lee, whose manuscript the tab credits to GPT-5.6 and GPT-6 Astra, stating that the author had solved the problem earlier in the month by a different and more general approach; the submitters of that claim replied that the arXiv posting followed their public release by a week and asked for a disclosure of AI use, which the abstract does not carry. The priority dispute is recorded, not adjudicated. The paper is not registered on the site's proof-claims tab, and the site labels the problem OPEN (page last edited 28 December 2025, as of 2026-10-07).