OpenAI claim summary for Math-609
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
Complete graph crossing numbers: For every complete graph K_n the claimed crossing number is exactly the Hill four-floor-factor expression, proving both the exact-value records and the matching lower-bound formulation.
With the hypotheses and conventions above, the claimed result addresses the whole mathematical assertion on this page.
Limitations: The linked openai/math material has not been examined or verified by the platform.
Manuscript
Contents
Guy's Crossing Number Conjecture
OpenAI's claim
Complete graph crossing numbers: The paper claims that the ordinary crossing number of $K_n$ equals one quarter of the product of the four consecutive half-integer floor factors. The statement holds at every positive integer order.Mathematical statement of the claimed result
Mathematical claim 1.
For every integer $n\ge3$, the manuscript asserts \[\operatorname{cr}(K_n)=\frac14\left\lfloor\frac n2\right\rfloor\left\lfloor\frac{n-1}2\right\rfloor\left\lfloor\frac{n-2}2\right\rfloor\left\lfloor\frac{n-3}2\right\rfloor.\] Here $\operatorname{cr}$ minimizes the number of proper edge-crossing points over ordinary plane drawings, allowing curved edges.Outline of the argument
Complete graph crossing numbers: The drawing is reduced to a controlled simple-arc form, then signed cycle intersections and endpoint orders are encoded algebraically. An even-node order detector supplies the rank obstruction giving the lower bound. A two-page drawing attains the proposed value, with the normalization argument ensuring that unrestricted continuous-arc drawings are covered.Formal verification
Family 165 describes Lean coverage for the two exact ordinary crossing formulas and drawings attaining them.Complete graph crossing numbers: The manuscript links BipartiteCrossing.lean (declaration OAI.Zarankiewicz.mainTarget_proof), CompleteCrossing.lean (declaration OAI.Paper170.complete_graph_crossing_number).
The documented selection includes this manuscript’s main assertion; that assertion retains the restrictions stated above.
This site has not run the Lean development. These links describe OpenAI’s selected formal statements and should be read with their stated scope.
Status caveat
OpenAI reports that an internal model produced the manuscripts. Their arguments have not been independently verified as proofs by this site. Any portion outside the documented formal scope may contain mistakes, and the catalogue label reports the announced mathematical claim.Sources
- OpenAI, The crossing number of complete graphs, 2026-09-23; citation key
OAI:The-crossing-number-of-complete-graphs-September-23-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: thm:main; Statement source: cor:lower. - Family 165: Lean scope.
- Comparator BipartiteCrossing.json.
- Comparator BipartiteCrossing.lean.
- Comparator CompleteCrossing.json.
- Comparator CompleteCrossing.lean.
- OpenAI catalogue entry.