TheoremDB
R446claimStatus: reproducedEvidence: ReproducedReplay: source onlyexhaustive over its scope

[#R446] The integral homology is Z, Z squared, Z, 0, 0

claim. Exact boundary ranks and Smith forms give H_0 = Z, H_1 = Z^2, H_2 = Z, and zero homology in degrees three and above, with no torsion.

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1Summary

Exact clique enumeration gives chain-group ranks \[ (\operatorname{rank}C_0,\ldots,\operatorname{rank}C_4) =(49,294,490,294,49). \] The boundary maps \(\partial_1,\ldots,\partial_4\) have ranks \[ (48,244,245,49). \] It follows that the Betti numbers are \[ (1,2,1,0,0). \]

The Smith normal form of each boundary matrix has only \(1\) among its nonzero invariant factors, with multiplicities \(48,244,245,49\), respectively. Thus every boundary image is primitive in its target chain group. Each homology group is a subgroup of a free quotient \(C_i/\operatorname{im}\partial_{i+1}\), so it is torsion-free. Hence \[ H_i(Y;\mathbb Z)\cong \begin{cases} \mathbb Z,&i=0,2,\\ \mathbb Z^2,&i=1,\\ 0,&i\geq3. \end{cases} \] This agrees with the published homotopy equivalence.

Reproduced evidence. Recorded scope: complete integral simplicial homology of the 49-vertex Lee-threshold-two complex.

2Evidence

Evidence package: source only

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

Verification source: arxiv.org ↗, Integral computation in lee7-artifact-exact-cliques-and-smith; comparison with Adams et al., Theorem 5.8

3What was measured

F vector
49, 294, 490, 294, 49
Boundary ranks
48, 244, 245, 49
Betti numbers
1, 2, 1, 0, 0
Euler characteristic
0

4How it connects

Implies (incoming)

Reproduces (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": "R446",
  "content_hash": null,
  "slug": "lee7-claim-integral-homology",
  "type": "claim",
  "title": "The integral homology is Z, Z squared, Z, 0, 0",
  "summary": "Exact boundary ranks and Smith forms give H_0 = Z, H_1 = Z^2, H_2 = Z, and zero homology in degrees three and above, with no torsion.",
  "relevance": "For Homotopy type of a Lee-metric Rips complex on the 7 by 7 torus, record lee7-claim-integral-homology (“The integral homology is Z, Z squared, Z, 0, 0”) records a bound, answer, status fact, or structural consequence. The record states: Exact boundary ranks and Smith forms give H_0 = Z, H_1 = Z^2, H_2 = Z, and zero homology in degrees three and above, with no torsion.",
  "relevance_source": "recorded",
  "body": "Exact clique enumeration gives chain-group ranks\n\\[\n(\\operatorname{rank}C_0,\\ldots,\\operatorname{rank}C_4)\n=(49,294,490,294,49).\n\\]\nThe boundary maps \\(\\partial_1,\\ldots,\\partial_4\\) have ranks\n\\[\n(48,244,245,49).\n\\]\nIt follows that the Betti numbers are\n\\[\n(1,2,1,0,0).\n\\]\n\nThe Smith normal form of each boundary matrix has only \\(1\\) among its nonzero invariant factors, with multiplicities \\(48,244,245,49\\), respectively. Thus every boundary image is primitive in its target chain group. Each homology group is a subgroup of a free quotient \\(C_i/\\operatorname{im}\\partial_{i+1}\\), so it is torsion-free. Hence\n\\[\nH_i(Y;\\mathbb Z)\\cong\n\\begin{cases}\n\\mathbb Z,&i=0,2,\\\\\n\\mathbb Z^2,&i=1,\\\\\n0,&i\\geq3.\n\\end{cases}\n\\]\nThis agrees with the published homotopy equivalence.",
  "status": "reproduced",
  "evidence_grade": "reproduced",
  "scope": {
    "kind": "bounded",
    "statement": "complete integral simplicial homology of the 49-vertex Lee-threshold-two complex",
    "bounds": {
      "side_length": {
        "min": 7,
        "max": 7
      },
      "lee_threshold": {
        "min": 2,
        "max": 2
      },
      "homological_degree": {
        "min": 0,
        "max": 4
      }
    },
    "exhaustive": true
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://arxiv.org/abs/2502.07134v2",
      "locator": "Integral computation in lee7-artifact-exact-cliques-and-smith; comparison with Adams et al., Theorem 5.8"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://arxiv.org/abs/2502.07134v2",
    "locator": "Integral computation in lee7-artifact-exact-cliques-and-smith; comparison with Adams et al., Theorem 5.8"
  },
  "relations": [
    {
      "slug": "R445",
      "title": "The complex is homotopy equivalent to the 2-torus",
      "object_type": "claim",
      "relation": "implies",
      "direction": "incoming"
    },
    {
      "slug": "R443",
      "title": "Exact clique enumeration and Smith-normal-form certificate",
      "object_type": "artifact",
      "relation": "reproduces",
      "direction": "incoming"
    },
    {
      "slug": "lee-rips-torus-7-homotopy",
      "title": "lee rips torus 7 homotopy",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

6Provenance

View source, identifiers, and projection details
Project
lee-rips-torus-7-homotopy
Locator
Integral computation in lee7-artifact-exact-cliques-and-smith; comparison with Adams et al., Theorem 5.8
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-24
Public record
R446
Stable alias
lee7-claim-integral-homology
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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