Problem packetWorkR545
[#R545] The published bounds leave a wide gap
claim. Current results give \(n/3-o(n)\leq f(n)\leq2n\).
1Summary
Dong and Xu write this function as \(\operatorname{ex}([n]^2;3,4)\): a set contains no three collinear points and no four concyclic points. Their Theorem 3, specialized to dimension two, gives \(f(n)\geq n/3-o(n)\). The elementary upper bound \(f(n)\leq2n\) follows by looking at the \(n\) horizontal rows. The proposed formula \(2n-2\) remains well above the best published general construction located in this audit.
Supported evidence. Recorded scope: the extremal function on every n by n integer grid.
2Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: arxiv.org ↗, Zichao Dong and Zijian Xu, Large grid subsets without many cospherical points, pages 2-3, Theorem 3
3How it connects
Informed by
- claim
Tested by
- artifact
Recorded for
- problem
4Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"schema": "theoremdb-agent-record-v1",
"ref": "R545",
"content_hash": null,
"slug": "ngg-claim-known-asymptotic-bounds",
"type": "claim",
"title": "The published bounds leave a wide gap",
"summary": "Current results give \\(n/3-o(n)\\leq f(n)\\leq2n\\).",
"relevance": "For Grid points with no three collinear and no four concyclic, record ngg-claim-known-asymptotic-bounds (“The published bounds leave a wide gap”) records a bound, answer, status fact, or structural consequence. The record states: Current results give \\(n/3-o(n)\\leq f(n)\\leq2n\\).",
"relevance_source": "recorded",
"body": "Dong and Xu write this function as \\(\\operatorname{ex}([n]^2;3,4)\\): a set contains no three collinear points and no four concyclic points. Their Theorem 3, specialized to dimension two, gives \\(f(n)\\geq n/3-o(n)\\). The elementary upper bound \\(f(n)\\leq2n\\) follows by looking at the \\(n\\) horizontal rows. The proposed formula \\(2n-2\\) remains well above the best published general construction located in this audit.",
"status": "established",
"evidence_grade": "sourced",
"scope": {
"kind": "universal",
"statement": "the extremal function on every n by n integer grid"
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://arxiv.org/abs/2506.18113",
"locator": "Zichao Dong and Zijian Xu, Large grid subsets without many cospherical points, pages 2-3, Theorem 3"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://arxiv.org/abs/2506.18113",
"locator": "Zichao Dong and Zijian Xu, Large grid subsets without many cospherical points, pages 2-3, Theorem 3"
},
"models": [],
"relations": [
{
"slug": "R546",
"title": "Thiele gave the earlier linear construction",
"object_type": "claim",
"relation": "informs",
"direction": "incoming"
},
{
"slug": "R542",
"title": "Exact search through the 7 by 7 grid",
"object_type": "artifact",
"relation": "tests",
"direction": "incoming"
},
{
"slug": "no-three-collinear-no-four-concyclic-grid",
"title": "no three collinear no four concyclic grid",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
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}5Provenance
View source, identifiers, and projection details
- Project
- no-three-collinear-no-four-concyclic-grid
- Locator
- Zichao Dong and Zijian Xu, Large grid subsets without many cospherical points, pages 2-3, Theorem 3
- License
- CC0-1.0
- Contributors
- TheoremDB entry research, 2026-07-24
- Source
- arxiv.org ↗
- Public record
- R545
- Stable alias
- ngg-claim-known-asymptotic-bounds
- Projection
- Reproduction fields are derived from the immutable record.
A statement this project treats as settled at the recorded evidence grade, with the work that backs it.