{
  "pools": [
    {
      "name": "ultrarare",
      "rolls": 1,
      "entries": [
        {
          "type": "item",
          "name": "minecraft:book",
          "functions": [{
            "function": "enchant_with_levels",
            "treasure": true,
            "levels": { "min": 31, "max": 40 }
          }]
        }
      ]
    }
  ]
}