TheoremDB
R1587claimStatus: reportedEvidence: SupportedReplay: source only

[#R1587] Dated status and exact unresolved remainder

claim. Unresolved in this packet after the dated source check. Strongest checked result: Cati and Pasechnik provide reproducible constructions through order 1208 for all known cases in that range and current tables beyond it. Their database improves many entries but continues to state the universal order-4k assertion as a conjecture. Exact unresolved remainder: Construct a Hadamard matrix of order 4k for every positive integer k, or give a positive k and prove that no matrix of order 4k exists.

View evidenceOpen source ↗

1Summary

The packet's cited sources and equivalent formulations were checked in the dated review recorded below.

Strongest checked result: Cati and Pasechnik provide reproducible constructions through order 1208 for all known cases in that range and current tables beyond it. Their database improves many entries but continues to state the universal order-4k assertion as a conjecture.

Supported evidence. Replay readiness: source only.

2Evidence

Evidence package: source only

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

Verification source: arxiv.org ↗, abstract and section 1.1

3Overview

Exact unresolved remainder: Construct a Hadamard matrix of order 4k for every positive integer k, or give a positive k and prove that no matrix of order 4k exists.

4What was measured

As of
2026-08-01
Strongest known result
Cati and Pasechnik provide reproducible constructions through order 1208 for all known cases in that range and current tables beyond it. Their database improves many entries but continues to state the universal order-4k assertion as a conjecture.
Exact open remainder
Construct a Hadamard matrix of order 4k for every positive integer k, or give a positive k and prove that no matrix of order 4k exists.

5How it connects

Supersedes

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": "R1587",
  "content_hash": null,
  "slug": "hadamard-matrix-conjecture-status-packet-quality-20260801",
  "type": "claim",
  "title": "Dated status and exact unresolved remainder",
  "summary": "Unresolved in this packet after the dated source check. Strongest checked result: Cati and Pasechnik provide reproducible constructions through order 1208 for all known cases in that range and current tables beyond it. Their database improves many entries but continues to state the universal order-4k assertion as a conjecture. Exact unresolved remainder: Construct a Hadamard matrix of order 4k for every positive integer k, or give a positive k and prove that no matrix of order 4k exists.",
  "relevance": "For Hadamard matrix conjecture, this successor gives readable dated status prose and the exact remaining research boundary.",
  "relevance_source": "recorded",
  "body": "The packet's cited sources and equivalent formulations were checked in the dated review recorded below.\n\nStrongest checked result: Cati and Pasechnik provide reproducible constructions through order 1208 for all known cases in that range and current tables beyond it. Their database improves many entries but continues to state the universal order-4k assertion as a conjecture.\n\nExact unresolved remainder: Construct a Hadamard matrix of order 4k for every positive integer k, or give a positive k and prove that no matrix of order 4k exists.",
  "status": "reported",
  "evidence_grade": "sourced",
  "scope": null,
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://arxiv.org/abs/2402.13202",
      "locator": "abstract and section 1.1"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://arxiv.org/abs/2402.13202",
    "locator": "abstract and section 1.1"
  },
  "relations": [
    {
      "slug": "R1072",
      "title": "Current status and unresolved remainder",
      "object_type": "claim",
      "relation": "supersedes",
      "direction": "outgoing"
    },
    {
      "slug": "hadamard-matrix-conjecture",
      "title": "hadamard matrix conjecture",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details
Project
hadamard-matrix-conjecture-source-review
Locator
abstract and section 1.1
License
CC0-1.0
Contributors
TheoremDB maintainers
Public record
R1587
Stable alias
hadamard-matrix-conjecture-status-packet-quality-20260801
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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