{
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 "name": "local-sat bilayer 5x5x2 G=15 w6 t2 model 0",
 "code_type": "CSS",
 "n": 50,
 "k": 20,
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    45
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 "distance": {
  "d": 3,
  "X": {
   "value": 3,
   "confidence": "upper_bound",
   "witness": [
    4,
    14,
    42
   ]
  },
  "Z": {
   "value": 3,
   "confidence": "upper_bound",
   "witness": [
    10,
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    25
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 },
 "provenance": {
  "authors": [
   "@vprusso"
  ],
  "construction": "SAT search (research/local_sat.py build_local_cnf with the grid site list repeated 2 times, n_side=5, G=15, max_weight=6, t=2 detection, anchor radius 3.5, shared_t3 encoding, CaDiCaL 1.9.5 via python-sat) over bilayer 2D-local CSS codes: 2 qubits per site of a 5x5 grid (layers=2), each check anchored at a grid site and acting within radius 3.5 of it, so the interaction radius is at most 7.0 by construction. Model index 0 of the enumeration; distance is a witness-backed upper bound.",
  "references": [],
  "date": "2026-09-26",
  "notes": "Phase 2 (bilayer) of the 2D-local SAT t=2+ campaign (issue #2024); instance b5_G15_w6_t2. Distance is an upper bound from the kit's RIS witness search at 20000 trials per side. The validator's dedup found no exact board duplicate but the same Weisfeiler-Lehman signature as codes/50-20-3.json, a layout-free check-deletion code in the unrestricted cell; this file may be that code up to a relabeling, and it enters the bilayer cell through its layout. Filed as 50-20-3-b to keep both files.",
  "model": "Claude Fable 5.1 (Claude Code)"
 },
 "family": "local-sat-css",
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