[{
  "_exerciseType": "Comment: DFA, NFA, REGEXP, GRAMMAR, PDA, TM",
  "exerciseType": "GRAMMAR",
  "totalTrueCases": 10,
  "totalFalseCases": 0,
  "containLetters": ["a", "b"],
  "randomStringLength": [0, 15],
  "description": "Find a regular grammar for the language over $\\{a, b\\}$ where the number of a's in any string is divisible by 3 .",
  "testCases": [
    {
      "regular-grammar": true,
      "ShowTestCase":true
    },
    {
      "": true,
      "ShowTestCase":true
    },
    {
      "aaa": true,
      "ShowTestCase":true
    },
    {
      "bbbbb": true,
      "ShowTestCase":true
    },
    {
      "bababa": true,
      "ShowTestCase":true
    },
    {
      "abbbbabbbbabb": true,
      "ShowTestCase":true
    },
    {
      "aabab": true,
      "ShowTestCase":true
    },
    {
      "bbabbabbbbabbababba": true,
      "ShowTestCase":true
    },
    {
      "ababbaaaaaaa": true,
      "ShowTestCase":true
    },
    {
      "bbbbbbbbbb": true,
      "ShowTestCase":true
    }
  ],
  "graph": {
    "nodes": [],
    "edges": []
  },
  "solution": ""
}]