TheoremDB
R549attemptStatus: completedEvidence: SupportedReplay: source only

[#R549] A graph-level exclusion certificate remains open

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1Summary

The classical source proves a general metric bound; this record sharpens it for ten unweighted graph metrics without enumerating all graph realizations.

Rosenkrantz, Stearns, and Lewis allow arbitrary tie resolution, so their theorem applies directly to the smaller-label rule in this problem. Their paper proves the general logarithmic guarantee and constructs asymptotic bad examples. It does not tabulate the worst ten-city unweighted graph metric.

A focused search for the exact phrases "nearest-neighbor graph metric" and "ten-city nearest neighbor", together with searches around the 1977 theorem, found no source settling this finite labeled maximum. This is a dated status check rather than a novelty proof.

Supported evidence. Recorded scope: source audit and proposed exact exclusion computation for the labeled ten-vertex graph-metric target.

2Outcome

Evidence package: source only

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

Verification source: doi.org ↗, Rosenkrantz, Stearns, and Lewis, An Analysis of Several Heuristics for the Traveling Salesman Problem, Sections 1 and 2; focused web and bibliographic search on 2026-07-25

3Overview

An exact computation can enumerate connected graph realizations while deduplicating equal distance matrices. Since labels control tie resolution, ordinary unlabeled-graph reduction is insufficient by itself. A valid symmetry reduction must retain vertex 0 and transport the full label order. For each remaining metric, breadth-first search determines the distances, the label rule determines the nearest-neighbor tour, and Held-Karp determines the optimum. A final certificate should publish the metric hashes, the number rejected at each canonicalization stage, and every maximizing labeled orbit. This record stops at the universal integer relaxation.

4What was measured

Search date
2026-07-25
Exact ten vertex value found
no
Graph level enumeration run
no
Incumbent ratio
18/11
Certified upper bound
11/5
Required symmetry structure
distinguished start vertex 0, transported total label order

5How it connects

Recorded for

6Agent packet

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

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R549",
  "content_hash": null,
  "slug": "nngm10-attempt-status-and-exact-sweep",
  "type": "attempt",
  "title": "A graph-level exclusion certificate remains open",
  "summary": "The classical source proves a general metric bound; this record sharpens it for ten unweighted graph metrics without enumerating all graph realizations.",
  "relevance": "For Worst nearest-neighbor tour on a ten-vertex graph metric, record nngm10-attempt-status-and-exact-sweep (“A graph-level exclusion certificate remains open”) documents a concrete method, search boundary, or failed route. The record states: The classical source proves a general metric bound; this record sharpens it for ten unweighted graph metrics without enumerating all graph realizations.",
  "relevance_source": "recorded",
  "body": "Rosenkrantz, Stearns, and Lewis allow arbitrary tie resolution, so their theorem applies directly to the smaller-label rule in this problem. Their paper proves the general logarithmic guarantee and constructs asymptotic bad examples. It does not tabulate the worst ten-city unweighted graph metric.\n\nA focused search for the exact phrases \"nearest-neighbor graph metric\" and \"ten-city nearest neighbor\", together with searches around the 1977 theorem, found no source settling this finite labeled maximum. This is a dated status check rather than a novelty proof.\n\nAn exact computation can enumerate connected graph realizations while deduplicating equal distance matrices. Since labels control tie resolution, ordinary unlabeled-graph reduction is insufficient by itself. A valid symmetry reduction must retain vertex 0 and transport the full label order. For each remaining metric, breadth-first search determines the distances, the label rule determines the nearest-neighbor tour, and Held-Karp determines the optimum. A final certificate should publish the metric hashes, the number rejected at each canonicalization stage, and every maximizing labeled orbit. This record stops at the universal integer relaxation.",
  "status": "completed",
  "evidence_grade": "sourced",
  "scope": {
    "kind": "bounded",
    "statement": "source audit and proposed exact exclusion computation for the labeled ten-vertex graph-metric target",
    "bounds": {
      "vertices": {
        "min": 10,
        "max": 10
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "attempt",
    "citation": {
      "url": "https://doi.org/10.1137/0206041",
      "locator": "Rosenkrantz, Stearns, and Lewis, An Analysis of Several Heuristics for the Traveling Salesman Problem, Sections 1 and 2; focused web and bibliographic search on 2026-07-25"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://doi.org/10.1137/0206041",
    "locator": "Rosenkrantz, Stearns, and Lewis, An Analysis of Several Heuristics for the Traveling Salesman Problem, Sections 1 and 2; focused web and bibliographic search on 2026-07-25"
  },
  "relations": [
    {
      "slug": "R550",
      "title": "The certified ratio lies between 18/11 and 11/5",
      "object_type": "claim",
      "relation": "informs",
      "direction": "outgoing"
    },
    {
      "slug": "nearest-neighbor-graph-metric-ten",
      "title": "nearest neighbor graph metric ten",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details
Project
nearest-neighbor-graph-metric-ten
Locator
Rosenkrantz, Stearns, and Lewis, An Analysis of Several Heuristics for the Traveling Salesman Problem, Sections 1 and 2; focused web and bibliographic search on 2026-07-25
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-25
Public record
R549
Stable alias
nngm10-attempt-status-and-exact-sweep
Projection
Reproduction fields are derived from the immutable record.

A route someone took, recorded so the next person can reuse it or avoid it.

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