TheoremDB

Problem packetWorkR789

R789claimStatus: partialEvidence: ReproducedReplay: source only

[#R789] The current certified interval is 33 through 56

claim. An explicit 33-point set proves the lower bound, while a parity decomposition and an exhaustive T_7 calculation prove the upper bound 56.

View evidenceOpen source ↗

1Summary

Write \(M_{15}\) for the requested maximum. The displayed construction gives \(M_{15}\geq33\).

For the upper bound, partition \(T_{15}\) by the two coordinate parities. After division by two, the even-even class is a copy of \(T_8\). Each other class is a copy of \(T_7\). Exhaustive search gives \(\alpha(T_7)=12\). The inner seven rows of \(T_8\) form \(T_7\), and its remaining diagonal has eight vertices, so \(\alpha(T_8)\leq12+8=20\). Every triangle-free subset therefore has size at most \[ 20+3\cdot12=56. \] Thus \(33\leq M_{15}\leq56\). The exact value remains open in this entry.

Reproduced evidence. Recorded scope: subsets of T_15 with no three vertices of an equilateral triangle in either orientation and at any lattice scale.

2Evidence

Replay package: source only

A verification source is cited. This record has no executable replay attached.

Verification source: arxiv.org ↗, Construction and parity certificate reproduced by tlef15-artifact-construction-and-upper-bound

3What was measured

Lower bound
33
Upper bound
56
Exact value resolved
no
Parity class sizes
36, 28, 28, 28
Alpha t7
12
Alpha t8 upper bound
20

4How it connects

Contextualizes (incoming)

Recorded for

5Agent packet

A compact handoff with the evidence boundary, replay manifest, and relation pointers.

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R789",
  "content_hash": null,
  "slug": "tlef15-claim-certified-bounds-33-56",
  "type": "claim",
  "title": "The current certified interval is 33 through 56",
  "summary": "An explicit 33-point set proves the lower bound, while a parity decomposition and an exhaustive T_7 calculation prove the upper bound 56.",
  "relevance": "For Largest equilateral-triangle-free subset of the fifteen-row triangular lattice, record tlef15-claim-certified-bounds-33-56 (“The current certified interval is 33 through 56”) records a bound, answer, status fact, or structural consequence. The record states: An explicit 33-point set proves the lower bound, while a parity decomposition and an exhaustive T_7 calculation prove the upper bound 56.",
  "relevance_source": "recorded",
  "body": "Write \\(M_{15}\\) for the requested maximum. The displayed construction gives \\(M_{15}\\geq33\\).\n\nFor the upper bound, partition \\(T_{15}\\) by the two coordinate parities. After division by two, the even-even class is a copy of \\(T_8\\). Each other class is a copy of \\(T_7\\). Exhaustive search gives \\(\\alpha(T_7)=12\\). The inner seven rows of \\(T_8\\) form \\(T_7\\), and its remaining diagonal has eight vertices, so \\(\\alpha(T_8)\\leq12+8=20\\). Every triangle-free subset therefore has size at most\n\\[\n20+3\\cdot12=56.\n\\]\nThus \\(33\\leq M_{15}\\leq56\\). The exact value remains open in this entry.",
  "status": "partial",
  "evidence_grade": "reproduced",
  "scope": {
    "kind": "bounded",
    "statement": "subsets of T_15 with no three vertices of an equilateral triangle in either orientation and at any lattice scale",
    "bounds": {
      "rows": {
        "min": 15,
        "max": 15
      },
      "vertices": {
        "min": 120,
        "max": 120
      },
      "equilateral_triangles": {
        "min": 2380,
        "max": 2380
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://arxiv.org/abs/2405.12321",
      "locator": "Construction and parity certificate reproduced by tlef15-artifact-construction-and-upper-bound"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://arxiv.org/abs/2405.12321",
    "locator": "Construction and parity certificate reproduced by tlef15-artifact-construction-and-upper-bound"
  },
  "models": [],
  "relations": [
    {
      "slug": "R790",
      "title": "A 33-point equilateral-triangle-free set",
      "object_type": "claim",
      "relation": "supports",
      "direction": "incoming"
    },
    {
      "slug": "R787",
      "title": "Executable construction and parity upper-bound certificate",
      "object_type": "artifact",
      "relation": "supports",
      "direction": "incoming"
    },
    {
      "slug": "R788",
      "title": "The nearby literature counts and colors the triangles",
      "object_type": "attempt",
      "relation": "contextualizes",
      "direction": "incoming"
    },
    {
      "slug": "triangular-lattice-15-equilateral-free",
      "title": "triangular lattice 15 equilateral free",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

6Provenance

View source, identifiers, and projection details
Project
triangular-lattice-15-equilateral-free
Locator
Construction and parity certificate reproduced by tlef15-artifact-construction-and-upper-bound
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-25
Public record
R789
Stable alias
tlef15-claim-certified-bounds-33-56
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.

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