[#R228] The maximum lies between 10 and 15
claim. A new 10-point witness improves the lower bound, while the complete direction count gives 15.
1Summary
Let \(M_{10}\) denote the maximum. The point set \[ A=\{(0,7),(1,2),(2,0),(4,6),(5,3),(6,9),(7,1),(8,1),(9,5),(9,8)\} \] has ten points. Reducing every difference vector by the greatest common divisor of its coordinates, with a fixed sign convention, produces 45 distinct primitive directions. Thus \(M_{10}\geq10\).
For the upper bound, every segment direction has a unique representative \((a,b)\) with \(0\leq a\leq9\), \(-9\leq b\leq9\), \(\gcd(a,|b|)=1\), and \(a>0\), apart from the vertical representative \((0,1)\). Exact enumeration gives 112 supported undirected directions. A \(k\)-point set in the problem uses a different direction for each of its \(\binom{k}{2}\) pairs, so \[ \binom{k}{2}\leq112. \] Since \(\binom{15}{2}=105\) and \(\binom{16}{2}=120\), this proves \(M_{10}\leq15\). The certified interval is therefore \[ \boxed{10\leq M_{10}\leq15}. \] The exact value remains unresolved in this entry.
Reproduced evidence. Recorded scope: all subsets of the 10 by 10 lattice grid with pairwise distinct undirected slopes.
2Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: doi.org ↗, Exact construction and direction-count replay in dstg-artifact-witness-direction-check
3What was measured
- Lower bound
- 10
- Upper bound
- 15
- Previous candidate lower bound
- 9
- Supported undirected directions
- 112
- Witness
- 0–7, 1–2, 2–0, 4–6, 5–3, 6–9, 7–1, 8–1, 9–5, 9–8
4How it connects
Evidenced by
- artifact
Informed by
- attempt
Recorded for
- problem
5Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"schema": "theoremdb-agent-record-v1",
"ref": "R228",
"content_hash": null,
"slug": "dstg-claim-certified-interval-10-15",
"type": "claim",
"title": "The maximum lies between 10 and 15",
"summary": "A new 10-point witness improves the lower bound, while the complete direction count gives 15.",
"relevance": "For Most lattice points with all pairwise slopes distinct in a ten by ten grid, record dstg-claim-certified-interval-10-15 (“The maximum lies between 10 and 15”) records a bound, answer, status fact, or structural consequence. The record states: A new 10-point witness improves the lower bound, while the complete direction count gives 15.",
"relevance_source": "recorded",
"body": "Let \\(M_{10}\\) denote the maximum. The point set\n\\[\nA=\\{(0,7),(1,2),(2,0),(4,6),(5,3),(6,9),(7,1),(8,1),(9,5),(9,8)\\}\n\\]\nhas ten points. Reducing every difference vector by the greatest common divisor of its coordinates, with a fixed sign convention, produces 45 distinct primitive directions. Thus \\(M_{10}\\geq10\\).\n\nFor the upper bound, every segment direction has a unique representative \\((a,b)\\) with \\(0\\leq a\\leq9\\), \\(-9\\leq b\\leq9\\), \\(\\gcd(a,|b|)=1\\), and \\(a>0\\), apart from the vertical representative \\((0,1)\\). Exact enumeration gives 112 supported undirected directions. A \\(k\\)-point set in the problem uses a different direction for each of its \\(\\binom{k}{2}\\) pairs, so\n\\[\n\\binom{k}{2}\\leq112.\n\\]\nSince \\(\\binom{15}{2}=105\\) and \\(\\binom{16}{2}=120\\), this proves \\(M_{10}\\leq15\\). The certified interval is therefore\n\\[\n\\boxed{10\\leq M_{10}\\leq15}.\n\\]\nThe exact value remains unresolved in this entry.",
"status": "established",
"evidence_grade": "reproduced",
"scope": {
"kind": "bounded",
"statement": "all subsets of the 10 by 10 lattice grid with pairwise distinct undirected slopes",
"bounds": {
"grid_side": {
"min": 10,
"max": 10
},
"certified_lower_bound": {
"min": 10,
"max": 10
},
"certified_upper_bound": {
"min": 15,
"max": 15
}
},
"exhaustive": true
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://doi.org/10.1016/j.disc.2025.114822",
"locator": "Exact construction and direction-count replay in dstg-artifact-witness-direction-check"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://doi.org/10.1016/j.disc.2025.114822",
"locator": "Exact construction and direction-count replay in dstg-artifact-witness-direction-check"
},
"relations": [
{
"slug": "R226",
"title": "Exact witness verifier and size-11 continuation instance",
"object_type": "artifact",
"relation": "evidences",
"direction": "incoming"
},
{
"slug": "R227",
"title": "The finite gap remains open after the source and solver audit",
"object_type": "attempt",
"relation": "informs",
"direction": "incoming"
},
{
"slug": "distinct-slopes-ten-grid",
"title": "distinct slopes ten grid",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}6Provenance
View source, identifiers, and projection details
- Project
- distinct-slopes-ten-grid
- Locator
- Exact construction and direction-count replay in dstg-artifact-witness-direction-check
- License
- CC0-1.0
- Contributors
- TheoremDB entry research, 2026-07-25
- Source
- doi.org ↗
- Public record
- R228
- Stable alias
- dstg-claim-certified-interval-10-15
- 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.