TheoremDB

Problem packetResearch packetR534

R534Sourced evidence

Existence of three MOLS of order 10 remains open

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Authored summary

A peer-reviewed 2026 SAT investigation identifies the existence of 3 MOLS(10) as an open problem.

The record cites sources for its explanation.

Recorded status: reported

Recorded scope: the reported existence status of three mutually orthogonal Latin squares of order 10, checked on 2026-07-24

Complete recorded scope and conditions
{
  "kind": "bounded",
  "statement": "the reported existence status of three mutually orthogonal Latin squares of order 10, checked on 2026-07-24",
  "bounds": {
    "order": {
      "min": 10,
      "max": 10
    },
    "square_count": {
      "min": 3,
      "max": 3
    }
  },
  "exhaustive": false
}

Originating problem: Three mutually orthogonal Latin squares of order ten

Authored record and scope
Authored title
Existence of three MOLS of order 10 remains open
Record type
claim
Stored status
reported
Evidence grade
sourced
Recorded scope data
{ "kind": "bounded", "statement": "the reported existence status of three mutually orthogonal Latin squares of order 10, checked on 2026-07-24", "bounds": { "order": { "min": 10, "max": 10 }, "square_count": { "min": 3, "max": 3 } }, "exhaustive": false }

2Authored explanation

Let \(N(10)\) be the largest number of pairwise orthogonal Latin squares of order 10. Parker's 1959 construction gives \(N(10)\geq2\). Bright, Keita, and Stevens state in their 2026 paper that it is unknown whether \(N(10)\geq3\), and call the construction or exclusion of 3 MOLS(10) a longstanding open problem.

Their exhaustive SAT results address a restricted hypothesis: one square in the proposed triple contains a \(4\times4\) Latin subsquare. Myrvold classified 28 possible mate-pattern pairs under that hypothesis. The SAT investigation verifies the absence of an orthogonal pair in 20 pattern cases and constructs an orthogonal pair in each of the other eight. Those eight cases still require analysis of the third square. The general three-square question remains undecided.

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Replay material: source only

3Evidence

Replay package: source only

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

Verification source: doi.org ↗, Curtis Bright, Amadou Keita, and Brett Stevens, Myrvold's Results on Orthogonal Triples of 10 x 10 Latin Squares: A SAT Investigation, Electronic Journal of Combinatorics 33(1) (2026), P1.30, DOI 10.37236/13960; abstract and pages 1-3 of arXiv:2503.10504v2

4What was measured

Restricted sat result

hypothesisone proposed square contains a 4 by 4 Latin subsquaremate pattern pairs28pair types excluded20pair types constructed8general triple resolvedno

5How it connects

Tested by

Recorded for

Machine-readable record

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json
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  "ref": "R534",
  "content_hash": null,
  "slug": "mols10-claim-currently-open",
  "type": "claim",
  "title": "Existence of three MOLS of order 10 remains open",
  "summary": "A peer-reviewed 2026 SAT investigation identifies the existence of 3 MOLS(10) as an open problem.",
  "relevance": "For Three mutually orthogonal Latin squares of order ten, record mols10-claim-currently-open (“Existence of three MOLS of order 10 remains open”) records a bound, answer, status fact, or structural consequence. The record states: A peer-reviewed 2026 SAT investigation identifies the existence of 3 MOLS(10) as an open problem.",
  "relevance_source": "recorded",
  "body": "Let \\(N(10)\\) be the largest number of pairwise orthogonal Latin squares of order 10. Parker's 1959 construction gives \\(N(10)\\geq2\\). Bright, Keita, and Stevens state in their 2026 paper that it is unknown whether \\(N(10)\\geq3\\), and call the construction or exclusion of 3 MOLS(10) a longstanding open problem.\n\nTheir exhaustive SAT results address a restricted hypothesis: one square in the proposed triple contains a \\(4\\times4\\) Latin subsquare. Myrvold classified 28 possible mate-pattern pairs under that hypothesis. The SAT investigation verifies the absence of an orthogonal pair in 20 pattern cases and constructs an orthogonal pair in each of the other eight. Those eight cases still require analysis of the third square. The general three-square question remains undecided.",
  "status": "reported",
  "evidence_grade": "sourced",
  "scope": {
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    "statement": "the reported existence status of three mutually orthogonal Latin squares of order 10, checked on 2026-07-24",
    "bounds": {
      "order": {
        "min": 10,
        "max": 10
      },
      "square_count": {
        "min": 3,
        "max": 3
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
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    "citation": {
      "url": "https://doi.org/10.37236/13960",
      "locator": "Curtis Bright, Amadou Keita, and Brett Stevens, Myrvold's Results on Orthogonal Triples of 10 x 10 Latin Squares: A SAT Investigation, Electronic Journal of Combinatorics 33(1) (2026), P1.30, DOI 10.37236/13960; abstract and pages 1-3 of arXiv:2503.10504v2"
    },
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  "formal_statement": null,
  "source": {
    "url": "https://doi.org/10.37236/13960",
    "locator": "Curtis Bright, Amadou Keita, and Brett Stevens, Myrvold's Results on Orthogonal Triples of 10 x 10 Latin Squares: A SAT Investigation, Electronic Journal of Combinatorics 33(1) (2026), P1.30, DOI 10.37236/13960; abstract and pages 1-3 of arXiv:2503.10504v2"
  },
  "models": [],
  "continuation": null,
  "relations": [
    {
      "slug": "R535",
      "title": "The published near triple contains exactly two orthogonal pairs",
      "object_type": "claim",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "R533",
      "title": "Exact replay of the order-10 near triple",
      "object_type": "artifact",
      "relation": "tests",
      "direction": "incoming"
    },
    {
      "slug": "three-mols-order-10",
      "title": "three mols order 10",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details

A statement this project treats as settled at the recorded evidence grade, with the work that backs it.

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