[{
  "_exerciseType": "Comment: DFA, NFA, REGEXP, GRAMMAR, PDA, TM",
  "exerciseType": "REGEXP",
  "totalTrueCases": 9,
  "totalFalseCases": 4,
  "containLetters": ["a", "b"],
  "randomStringLength": [0, 15],
  "description": "Give a regular expression whose language is strings over $\\{a, b\\}$ in which every a is either immediately preceeded or immediately followed by b.",
  "testCases": [
    {
      "": true,
      "ShowTestCase": true
    },
    {
      "bbbbbbbbbbbbbbb": true,
      "ShowTestCase": true
    },
    {
      "a": false,
      "ShowTestCase": true
    },
    {
      "aa": false,
      "ShowTestCase": true
    },
    {
      "baa": false,
      "ShowTestCase": true
    },
    {
      "baaab": false,
      "ShowTestCase": true
    },
    {
      "ba": true,
      "ShowTestCase": true
    },
    {
      "ab": true,
      "ShowTestCase": true
    },
    {
      "abba": true,
      "ShowTestCase": true
    },
    {
      "bbbaabbabbbbbbb": true,
      "ShowTestCase": true
    },
    {
      "abababab": true,
      "ShowTestCase": true
    },
    {
      "bababaaba": true,
      "ShowTestCase": true
    },
    {
      "baaba": true,
      "ShowTestCase": true
    }
  ],
  "graph": {
    "nodes": [],
    "edges": []
  },
  "solution": ""
}]