TheoremDB
R534claimStatus: reportedEvidence: SupportedReplay: source only

[#R534] Existence of three MOLS of order 10 remains open

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

View evidenceOpen source ↗

1Summary

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.

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

2Evidence

Evidence 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

3What was measured

Status checked
2026-07-24
Known lower bound
2
Target bound
3
Current source revision
arXiv:2503.10504v2, 2026-01-21

Restricted sat result

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

4How it connects

Tested by

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": "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": {
    "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
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "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"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "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"
  },
  "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"
    }
  ]
}

6Provenance

View source, identifiers, and projection details
Project
three-mols-order-10
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
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-24
Public record
R534
Stable alias
mols10-claim-currently-open
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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