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 "provenance": {
  "authors": [
   "Lin, Hsiang-Ku",
   "Pryadko, Leonid P."
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  "construction": "Two-block group algebra (2BGA) code over C_8 x C_2: a={1, r^2}, b={1, s r^5, s r^4, r^2, s r^7, s r^6} (Lin & Pryadko, arXiv:2306.16400, Table 1).",
  "references": [
   "arXiv:2306.16400"
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  "date": "2023",
  "novelty": "known_parameters",
  "notes": "Literature baseline (arXiv:2306.16400, Lin & Pryadko, 28 Jun 2023). Two-block group algebra code reconstructed from the published group presentation; distance d=4 taken from the paper's Table 1 and certified by an explicit non-stabilizer witness on each side (regenerated via the research kit's RIS search). Literature novelty confirmed by manual cross-check: arXiv:2306.16400 Table 1 explicitly reports the [[32,8,4]] parameters with W=8. The verifier's 'literature novelty UNVERIFIED' label is by-design (validate_candidate.py performs no literature lookup) and is intentionally not overridden.\n\nLayout certification: a verifier-accepted honest bilayer layout (stacked 4x4 grid, 2 qubits per site, layers=2, measured interaction radius ~4.243) was found by @mathysrennela (Aug 2026). It earns the code the local-2d-bilayer class and makes the site's geometric efficiency g = 4kd^2/(n rho^2 r^4) computable. Code authorship unchanged; layout credit to @mathysrennela.",
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  "notes": "Interleaved two-block extraction (Bravyi et al. arXiv:2308.07915 Table 5 style): joint reset and measurement layers, 9 data CX layers per round; X-check term slots [6, 1, 2, 7, 4, 3, 8, 5], Z-check term slots [1, 6, 5, 0, 7, 2, 3, 4] over terms A_0..A_1, B_0..B_5; terms recovered from H alone by a commuting permutation decomposition. Only 24 slot assignments satisfy the overlap-parity criterion at this depth and the first one screened holds full distance; the claim then survived 2 seeds x 1000 RIS trials per basis and an observable-constrained seeded BP+OSD search over symmetric seeds, whose lightest undetected logical fault set is weight 4 in both bases.",
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