TheoremDB

Problem packetResearch packetR716

R716Computational evidence

The exact maximum is M(50)=8

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Authored summary

The set {8,18,22,23,30,41,47,50} attains eight, and a complete search finds no valid nine-element subset.

The record reports a computation within its stated scope.

Recorded status: established

Recorded scope: all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection

Complete recorded scope and conditions
{
  "kind": "bounded",
  "statement": "all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection",
  "bounds": {
    "ambient_maximum": {
      "min": 50,
      "max": 50
    },
    "set_size": {
      "min": 8,
      "max": 10
    }
  },
  "exhaustive": true
}

Originating problem: Largest jointly sum-and-difference-distinct subset of {1,...,50}

Authored record and scope
Authored title
The exact maximum is M(50)=8
Record type
claim
Stored status
established
Evidence grade
computational
Recorded scope data
{ "kind": "bounded", "statement": "all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection", "bounds": { "ambient_maximum": { "min": 50, "max": 50 }, "set_size": { "min": 8, "max": 10 } }, "exhaustive": true }

2Authored explanation

For a \(k\)-element set, the combined collection has \(2\binom{k}{2}=k(k-1)\) entries. Every positive difference and every sum lies in \(\{1,\ldots,99\}\), so \(k(k-1)\leq99\) and \(k\leq10\).

The set \[ S=\{8,18,22,23,30,41,47,50\} \] produces 56 distinct combined values, with minimum 1 and maximum 97. This proves \(M(50)\geq8\).

The executable certificate enumerates every increasing nine-tuple in \(\{1,\ldots,50\}\). It carries a bit mask for all sums and differences created by the current partial set. An extension is retained exactly when its new values avoid the mask and one another. The search reaches no depth-nine leaf. The property passes to subsets, so every valid set of size at least nine would contain a valid nine-element subset. Hence \(M(50)\leq8\), and the two bounds give \[ M(50)=8. \]

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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 ↗, Independent exhaustive certificate sdd50-artifact-exhaustive-nine, executed on 2026-07-24

4What was measured

5How it connects

Evidenced by

Recorded for

Machine-readable record

Copy the structured record when continuing this work with an agent.

json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R716",
  "content_hash": null,
  "slug": "sdd50-claim-exact-value",
  "type": "claim",
  "title": "The exact maximum is M(50)=8",
  "summary": "The set {8,18,22,23,30,41,47,50} attains eight, and a complete search finds no valid nine-element subset.",
  "relevance": "This records a result, observation, or conjecture used to assess the target problem.",
  "relevance_source": "derived",
  "body": "For a \\(k\\)-element set, the combined collection has \\(2\\binom{k}{2}=k(k-1)\\) entries. Every positive difference and every sum lies in \\(\\{1,\\ldots,99\\}\\), so \\(k(k-1)\\leq99\\) and \\(k\\leq10\\).\n\nThe set\n\\[\nS=\\{8,18,22,23,30,41,47,50\\}\n\\]\nproduces 56 distinct combined values, with minimum 1 and maximum 97. This proves \\(M(50)\\geq8\\).\n\nThe executable certificate enumerates every increasing nine-tuple in \\(\\{1,\\ldots,50\\}\\). It carries a bit mask for all sums and differences created by the current partial set. An extension is retained exactly when its new values avoid the mask and one another. The search reaches no depth-nine leaf. The property passes to subsets, so every valid set of size at least nine would contain a valid nine-element subset. Hence \\(M(50)\\leq8\\), and the two bounds give\n\\[\nM(50)=8.\n\\]",
  "status": "established",
  "evidence_grade": "computational",
  "scope": {
    "kind": "bounded",
    "statement": "all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection",
    "bounds": {
      "ambient_maximum": {
        "min": 50,
        "max": 50
      },
      "set_size": {
        "min": 8,
        "max": 10
      }
    },
    "exhaustive": true
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://doi.org/10.1109/TCOM.1986.1096587",
      "locator": "Independent exhaustive certificate sdd50-artifact-exhaustive-nine, executed on 2026-07-24"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://doi.org/10.1109/TCOM.1986.1096587",
    "locator": "Independent exhaustive certificate sdd50-artifact-exhaustive-nine, executed on 2026-07-24"
  },
  "models": [],
  "continuation": null,
  "relations": [
    {
      "slug": "R715",
      "title": "Exhaustive nine-element branch certificate",
      "object_type": "artifact",
      "relation": "evidences",
      "direction": "incoming"
    },
    {
      "slug": "R717",
      "title": "The condition strengthens the Golomb ruler and Sidon property",
      "object_type": "claim",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "sum-difference-distinct-subset-50",
      "title": "sum difference distinct subset 50",
      "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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