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var hi = "hello"                          // Global

function grandparent () {
  var one = 1                             // Private to `grandparent`, `parent`, and `child`
  console.log( hi, one, two, three )      // hello, 1, undefined, undefined
  parent()

  function parent () {
    var two = 2                           // Private to `parent`, and `child`
    console.log( hi, one, two, three )    // hello, 1, 2, undefined
    child()

    function child () {
      var three = 3                       // Private to `child`
      console.log( hi, one, two, three )  // hello, 1, 2, 3
    }
  }
}

grandparent()
console.log( hi, one, two, three )        // hello, undefined, undefined, undefined
console.log( grandparent, parent, child ) // Function, undefined, undefined