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The claim. Let $\mathcal F=\{K_{1,2},2K_2\}$, the two-edge star and the two-edge matching. Any graph with two edges contains two edges at a common vertex or two disjoint edges, and a single edge contains neither, so $\mathrm{ex}(n;\mathcal F)=1$ for $n\ge2$; a graph with no $K_{1,2}$ is a matching and a graph with no $2K_2$ is a star or a triangle, so $\mathrm{ex}(n;K_{1,2})=\lfloor n/2\rfloor$ and $\mathrm{ex}(n;2K_2)=n-1$ for $n\ge4$. Both individual extremal numbers are unbounded while the joint one is $1$, so no $G\in\mathcal F$ satisfies $\mathrm{ex}(n;G)\ll_{\mathcal F}\mathrm{ex}(n;\mathcal F)$, and the answer to the printed wording of Problem 180 is no.

The postings. Y. Wigderson, The Erdős--Simonovits compactness conjecture needs more assumptions, a two-page note on the author's page (undated; the file's metadata gives 25 July 2022, which names this page and is not a verified posting date), Observation on p. 1, paged at the result page; the note attributes the example to Jordan Lefkowitz, points to Chvátal--Hanson for a more general form, reports Simonovits's private communication that such counterexamples had long been known, and states in its p. 2 Conjecture the no-forest form that Simonovits suggested, which it leaves open. The same family was posted on the problem's thread on 19 August 2025 (post 124, the account zach hunter), as a folklore counterexample that leaves the question open for every other family. Chapter 10 of OpenAI's 2026 report prints the same three values for $n\ge4$, cites the note and calls the family folklore (chapter card).

Why it is rejected. It answers the printed wording, not the corrected statement. Problem 180 judges the corrected Statement, which follows the site's curator in excluding the families $\{H_1,H_2\}$ of a star and a matching with at least two edges each; the problem page's Notes give the evidence. This family is one of those excluded, so the counterexample settles no instance of the corrected Statement. The problem page's Notes credit the result.

Acceptance. No outside acceptance of this note is documented. The site's curator records the family in the problem's commentary as the folklore counterexample provided by Hunter, with $\mathrm{ex}(n;\mathcal F)\ll1$ and $\mathrm{ex}(n;H_i)\asymp n$ for both members (erdosproblems.com/180, commentary last edited 31 August 2026), but credits the thread post rather than this note, writes that the conjecture may still hold for every other family, and attaches the DISPROVED (LEAN) label to the accepted OpenAI disproof of the form that excludes forests; that credit does not treat the family as settling the problem, so reviewed is not listed. The note is unpublished, so refereed is not listed; the elementary check on the problem page is this project's and warrants nothing. The no-forest variant is not this claim's subject.