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Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.

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Claim. The statement of [[problems/ramsey_theory/E0547/_index|Problem 547]] as the site prints it, with no range on nn, is false. For n=1n=1 the tree is K1K_1 and the host K2n−2K_{2n-2} is K0K_0, which has no vertex, so neither color class of a two-coloring of K0K_0 contains a copy of K1K_1, and R(K1)=1>0=2n−2R(K_1)=1>0=2n-2. Two Lean developments in Boris Alexeev's repository of Lean proofs, both added on 2026-08-26 and linked above at a pinned commit, prove this. Erdos547.lean proves Erdos547.not_erdos_547, the negation of the statement that for every nn, every tree TT on Fin n and every simple graph GG on Fin (2 * n - 2), TT is contained in GG or in its complement; the proof applies the statement to the one-vertex tree. Erdos547b.lean proves Erdos547b.not_literalErdos547, the negation of LiteralErdos547, which the file's docstring calls "the literal, unqualified assertion printed in the problem database" and which is the same statement, by applying it to the one-vertex tree and the empty graph on Fin 0; that file's not_erdos_547 restates the result in the first file's form. Neither file names an author, so the claim is recorded under the repository owner's name. The main theorems of the two files are large-order bounds recorded elsewhere: Erdos547.erdos_547 on [[problems/ramsey_theory/E0547/claims/2026_08_26_alexeev|the large-order claim page]], and Erdos547b.eventually_erdos_547, Zhao's theorem, as a formalization link on Zhao's claim page.

Depends on. No page of this wiki.

Why it is rejected. It answers the site's wording, not the corrected statement. Problem 547 judges its corrected Statement, the bound for every tree on n≥2n\geq2 vertices, which excludes exactly the one-vertex tree; the problem page's Notes give the evidence for that reading. The failure at n=1n=1 therefore settles no instance of the corrected Statement. The problem page's Notes credit the result.

Standing. Rejected. The failure needs no source: it is the check written in the Claim above, and Hua Xu noted it in the site's discussion on 1 May 2026, and the site has not addressed it. No outside reviewer has examined either file, and this corpus has not built them, so they give formalization links and no formalized evidence; a build would leave the rejection unchanged, since the rejection concerns what the theorems answer.