The Heilbronn Triangle Problem
Status Open · unsolvedmath.comLLM status Open unverified
Top Open Problems unknownunknown Not reported cataloguedOpenOpenStatement
Definitions and mathematical statement
Shared notation.
$\mathbb N$, $\mathbb Z$, $\mathbb Q$, $\mathbb R$, and $\mathbb C$ denote the natural numbers, integers, rationals, reals, and complex numbers, respectively. All additional parameters and hypotheses are specified in the question.Statement recorded in the supplied source.
For an $n$-point subset $P$ of the unit square, take the least area of a triangle with three distinct vertices in $P$. Determine the supremum of this least area over all choices of $P$, including its asymptotic order as $n$ grows.Formulation references: [S1], [S2].
Short English statement
For an $n$-point subset $P$ of the unit square, take the least area of a triangle with three distinct vertices in $P$. Determine the supremum of this least area over all choices of $P$, including its asymptotic order as $n$ grows.Sources
- S1 ULAM.AI and the UnsolvedMath Contributors, UnsolvedMath: A Curated Collection of Open Mathematics Problems, record 1215 (GEO-024). Catalogue attribution under CC BY 4.0. https://huggingface.co/datasets/ulamai/UnsolvedMath.
- S2 Original problem formulation and mathematical context. https://mathworld.wolfram.com/HeilbronnTriangleProblem.html.
Statement licence: CC-BY-4.0 · Source file
Contributions 2
OpenAI claim summary for Math-2196
Heilbronn triangle power improvement: The improved construction gives a lower bound c n^(-2+eta) for the best achievable smallest triangle, but no matching upper bound, sharp asymptotic order, or optimal configurations.
This page records partial support. Complete resolution of the catalogue question is not established by this record.
Heilbronn Triangle Problem
OpenAI's claim
Heilbronn triangle power improvement: For every sufficiently large $n$, the paper claims $n$ points in the unit square with every triangle area at least $c n^{-2+\eta}$ for fixed positive $c,\eta$. This contradicts an upper bound with exponent arbitrarily close to minus two.Mathematical statement of the claimed result
Mathematical claim 1.
For $n\ge3$, define $\Delta(n)=\max_{P\subset[0,1]^2,\ |P|=n}\min_{\{p,q,r\}\subset P}\tfrac12|\det(q-p,r-p)|$. The claim gives absolute $\eta,c>0,n_0$ with \[\Delta(n)\ge cn^{-2+\eta}\quad(n\ge n_0).\] It therefore refutes the proposed upper estimate $\Delta(n)=O_\epsilon(n^{-2+\epsilon})$ for every $\epsilon>0$, by taking $\epsilon<\eta$. A fixed affine scaling transfers the construction to a unit disk.Outline of the argument
Heilbronn triangle power improvement: Two congruence conditions govern randomly sampled integer columns. Norm-polynomial residues control small nonzero determinants, while an independent quadratic-surface condition and lattice counts handle zero determinants. The Chinese remainder construction combines them, repeated labels supply a deletion saving, and scaling transfers the retained determinant lower bound to triangle areas.Formal verification
Family 191 describes Lean coverage for the triangle-area improvement along an unbounded sequence of sizes; the every-large-size extension is broader.Heilbronn triangle power improvement: The manuscript links HeilbronnTriangle.lean.
The documented selection does not cover the entire manuscript assertion relevant here.
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, A power improvement in the Heilbronn triangle lower bound, 2026-09-25; citation key
OAI:A-power-improvement-in-the-Heilbronn-triangle-lower-bound-September-25-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: intro:main. - Family 191: Lean scope.
- Comparator HeilbronnTriangle.json.
- Comparator HeilbronnTriangle.lean.
- OpenAI catalogue entry.
OpenAI claim summary for Math-2196
Heilbronn triangle power improvement: The improved construction gives a lower bound c n^(-2+eta) for the best achievable smallest triangle, but no matching upper bound, sharp asymptotic order, or optimal configurations.
This page records partial support. Complete resolution of the catalogue question is not established by this record.
The Heilbronn Triangle Problem
OpenAI's claim
Heilbronn triangle power improvement: For every sufficiently large $n$, the paper claims $n$ points in the unit square with every triangle area at least $c n^{-2+\eta}$ for fixed positive $c,\eta$. This contradicts an upper bound with exponent arbitrarily close to minus two.Mathematical statement of the claimed result
Mathematical claim 1.
For $n\ge3$, define $\Delta(n)=\max_{P\subset[0,1]^2,\ |P|=n}\min_{\{p,q,r\}\subset P}\tfrac12|\det(q-p,r-p)|$. The claim gives absolute $\eta,c>0,n_0$ with \[\Delta(n)\ge cn^{-2+\eta}\quad(n\ge n_0).\] It therefore refutes the proposed upper estimate $\Delta(n)=O_\epsilon(n^{-2+\epsilon})$ for every $\epsilon>0$, by taking $\epsilon<\eta$. A fixed affine scaling transfers the construction to a unit disk.Outline of the argument
Heilbronn triangle power improvement: Two congruence conditions govern randomly sampled integer columns. Norm-polynomial residues control small nonzero determinants, while an independent quadratic-surface condition and lattice counts handle zero determinants. The Chinese remainder construction combines them, repeated labels supply a deletion saving, and scaling transfers the retained determinant lower bound to triangle areas.Formal verification
Family 191 describes Lean coverage for the triangle-area improvement along an unbounded sequence of sizes; the every-large-size extension is broader.Heilbronn triangle power improvement: The manuscript links HeilbronnTriangle.lean.
The documented selection does not cover the entire manuscript assertion relevant here.
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, A power improvement in the Heilbronn triangle lower bound, 2026-09-25; citation key
OAI:A-power-improvement-in-the-Heilbronn-triangle-lower-bound-September-25-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: intro:main. - Family 191: Lean scope.
- Comparator HeilbronnTriangle.json.
- Comparator HeilbronnTriangle.lean.
- OpenAI catalogue entry.