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 answer to Problem 1037 is no. For every large divisible by there is a graph on vertices with no degree occurring more than twice, at least distinct degrees, that is , and every clique and every independent set on vertices; so for every the hypothesis of the question holds for large and no trivial subgraph is larger than a constant times . The construction, from the forum comment of 22 September 2025 that wrote it out after a suggestion in the thread the day before and an earlier sketch of 13 September 2025, in the corpus's words: take four copies of one realization of the random graph on vertices with edge probability whose clique and independence numbers are of order ; list the vertices of as and those of as , each list in decreasing order of degree; join to exactly when ; add every edge between and and none between and . The degrees on are then pairwise distinct, and so are those on , so every degree occurs at most twice. Writing for the degree of a vertex in its copy of the base graph, has degree and has degree ; the base degrees of the random graph all lie within of , so the degree of falls below every degree on once exceeds by more than the spread of the base degrees, which gives at least distinct degrees. The site's commentary and the comment state the count as at least : the comment assumes without loss of generality that at least half of the base graph's vertices have degree at most and concludes that the degrees of for do not appear on ; a bound on the base degrees from above alone does not exclude a with just past sharing its degree with a of low base degree, so the comment's justification does not establish the exact count , and the formalization proves the weaker count (below). A clique or independent set of the whole graph meets each copy in a clique or independent set of the base graph, so both numbers are at most four times those of the base graph. A vertex count not divisible by is handled by adding a few nearly universal vertices. The site credits the construction jointly to Stijn Cambie, Koishi Chan and Zach Hunter.
Depends on. Nothing in this wiki; the argument is self-contained.
Formalization. The file src/v4.29.1/ErdosProblems/Erdos1037.lean of Boris
Alexeev's repository lean-proofs (Lean v4.29.1, Mathlib v4.29.1; about 2,200
lines at the pinned commit of 2026-09-15) declares itself a formalization of
this construction: its header names Stijn Cambie, Zach Hunter and KoishiChan as
informal authors and Aristotle and Boris Alexeev as formal authors, and its
docstring describes four copies of a random graph with degrees spread by a cross
join. Alexeev announced it in the site's thread on 19 January 2026 as
Aristotle's formalization of the proof by Cambie, Hunter and KoishiChan, and
added its final theorem the same day after the curator stated the quantifier
reading recorded below. The file proves Erdos1037.Theorem_Main: there is a
constant such that for every and every large
divisible by some graph on Fin n has every degree at most twice, more than
distinct degrees, and clique and independence numbers at
most . Its degree count is num_distinct_degrees_ge: at least
distinct degrees for the graph built on a base graph
on vertices with maximum degree and minimum degree
, and for the random base, that
is ; the file does not prove the count ,
and the variant cambie_chan_hunter of the formal-conjectures statement file
ErdosProblems/1037.lean
at the pinned commit, which states , has proof sorry and no
formal_proof attribute. The file also proves Erdos1037.not_erdos_1037, the
negation of the statement that for every and , every large
graph with at least distinct degrees has clique or
independence number at least . That negated statement carries no
hypothesis on degrees occurring at most twice, so it is a weaker negation than
the one of the formal-conjectures statement, while Theorem_Main carries the
hypothesis. That statement file (not a formalization of the result; the problem
page carries its bare pointer) names this file in its formal_proof attribute.
The file closes with #print axioms not_erdos_1037 and a comment reporting
propext, Classical.choice and Quot.sound. This repository records no
build, replay or axiom audit of the file and no review of the fidelity of its
statements to the site's question, so the page lists no formalized evidence.
Acceptance. Reviewed: the site's curator, Thomas Bloom, labels the problem DISPROVED (LEAN), credits the construction to the three authors in the commentary (Bloom took no part in it), and in the thread (19 January 2026) fixed the quantifier reading of the question that the construction refutes: for every and every , every large graph with at least distinct degrees has a trivial subgraph on more than vertices (the problem page's Formulation records this reading with the at-most-twice hypothesis restored). The community database records the problem as disproved. Not refereed: the construction exists only as forum comments, and no paper or preprint of it is known. The gap in the comment's count noted above is this page's own observation; the acceptance rests on the site's acceptance, not on a local review.