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Claim. For $f\in C[-1,1]$ let $L_nf$ interpolate $f$ at the $n$ roots of $T_n$. For a fixed $x_0\in[-1,1]$ let $C_{x_0}(f)$ be the set of finite real cluster values of $L_nf(x_0)$, so that $C_{x_0}(f)=\emptyset$ means $\lvert L_nf(x_0)\rvert\to\infty$. Theorem 1.1 of the note Chebyshev–Lagrange limit sets and the variants of an Erdős problem (dated 29 April 2026, no byline, hosted at ulam.ai) states two things: (a) for every $x_0$ and every nonempty closed $A\subseteq[-1,1]$, some continuous $f$ has $C_{x_0}(f)=A$; (b) some $f$ has $C_{x_0}(f)=\emptyset$ exactly when $x_0=\cos(\pi\alpha)$ with $\alpha$ rational of odd denominator. The note proves (a) and the negative direction of (b) (Section 6). The positive direction of (b) is Erdős's divergence theorem of 1941 with his 1943 corrections. At Erdős's points $x_0=\cos(\pi p/q)$ with $p,q$ odd, (a) and (b) give every closed $A\subseteq[-1,1]$, the empty set included. That is Problem 1151 as its Formulation reads it. Section 7 shows that two other readings fail. The points with a nonempty cluster set always include a dense set, so no proper closed set is the set of such points (Theorem 7.1). No $f$ has $C_x(f)=\{-1,1\}$ at every $x$ (Proposition 7.2).

Depends on. No page of this wiki: the positive direction of (b) is Erdős's 1941 theorem with its 1943 corrections, cited from the literature.

Standing. A manuscript claim, claimed. Chojecki posted the note in the site's thread on 30 April 2026, writing that GPT-5.5 Pro produced it. A reply the same day and another on 6 May 2026 report checks made with ChatGPT; neither is a review. The Lean development linked above was posted in the thread on 6 May 2026, made with ChatGPT and Codex as its poster wrote. It declares itself a formalization of Theorem 1.1(a) of the note and leaves (b) aside. It is not built or audited in this repository, so it gives no formalized evidence. Not reviewed: the site's label is OPEN (page last edited 23 January 2026), and its commentary does not mention the note. Not refereed: no journal or arXiv version is known.