Information required: AIG format

[InputBlackBoxOutput]

I would like to know the format for the AIG generated by the json -aig command

Example output:

  "models": {
    "$xor:0:0:1:1:1": [
      /*   0 */ [ "port", "A", 0 ],
      /*   1 */ [ "port", "B", 0 ],
      /*   2 */ [ "nport", "B", 0 ],
      /*   3 */ [ "nport", "A", 0 ],
      /*   4 */ [ "nand", 2, 3 ],
      /*   5 */ [ "nand", 0, 1 ],
      /*   6 */ [ "and", 4, 5, "Y", 0 ]
    ],
    "$and:0:0:1:1:1": [
      /*   0 */ [ "port", "A", 0 ],
      /*   1 */ [ "port", "B", 0 ],
      /*   2 */ [ "and", 0, 1, "Y", 0 ]
    ]
  }

I looked up the documentation but I am unclear on the terms like port, nport and others. I also looked up ABC website to find this document but it does not explain the format used by yosys