{
  "base_model": "Qwen/Qwen3-4B-Base",
  "loop_start": 13,
  "loop_end": 22,
  "loop_k": 3,
  "unrolled": true,
  "num_hidden_layers": 54,
  "note": "Layers 13-21 of the base model run three times; the checkpoint stores them unrolled."
}