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 "provenance": {
  "authors": [
   "@vprusso"
  ],
  "origin": "submission",
  "construction": "search",
  "date": "2026-10-13",
  "references": [
   "arXiv:2609.30069"
  ],
  "notes": "Halved CPM pair-partition code of arXiv:2609.30069 (Definition 1, reversing fold of Proposition 4) at (J,L)=(4,10), lift P=18. Exponent array E (rows a=0..3, columns l=0..9): [[10, 0, 1, 2, 15, 8, 14, 10, 16, 4], [17, 13, 15, 4, 7, 11, 9, 1, 4, 3], [7, 13, 8, 13, 17, 12, 0, 13, 1, 16], [17, 0, 9, 16, 10, 14, 11, 7, 14, 12]]. Off-diagonal pair partitions M: {\"0,1\": [[0, 2], [1, 3], [4, 9], [5, 6], [7, 8]], \"0,2\": [[0, 9], [1, 5], [2, 8], [3, 7], [4, 6]], \"0,3\": [[0, 8], [1, 2], [3, 4], [5, 9], [6, 7]], \"1,2\": [[0, 3], [1, 8], [2, 5], [4, 7], [6, 9]], \"1,3\": [[0, 9], [1, 7], [2, 3], [4, 5], [6, 8]], \"2,3\": [[0, 6], [1, 9], [2, 7], [3, 5], [4, 8]]}. The paper publishes no generators for its halved instances; this code is from a random search over the template. Distance 10 is the lightest logical found in 1000000 refutation trials (upper bound). The paper's table lists [[90,21,11]] for this P, which this search did not reach.",
  "search_budget": {
   "candidates_screened": 390000,
   "ris_trials_per_side": 960000000,
   "tool": "halved_pp.py templates; verify/heuristic_distance.py Pauli RIS; gf2_fast on the symplectic doubling under random per-qubit symplectic frames (frame_screen.py)",
   "notes": "Pauli-weight RIS screen, then 960 random per-qubit symplectic frames x 1,000,000 gf2_fast trials on the doubling (Perlmutter job 59676168, 2026-10-11). Lightest Pauli-weight logical found: 10; no frame found lighter. Upper bound only."
  },
  "model": "Claude Fable 5.1"
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}