text: //// [unionTypeEquivalence.ts]
  // A | B is equivalent to A if B is a subtype of A
  class C { }
  class D extends C { foo() { } }
  var x: C;
  var x : C | D;
  
  // A | B is equivalent to B | A.
  var y: string | number;
  var y : number | string;
  
  // AB | C is equivalent to A | BC, where AB is A | B and BC is B | C.
  var z : string | number | boolean;
  var z : (string | number) | boolean;
  var z : string | (number | boolean);
  var AB : string | number;
  var BC : number | boolean;
  var z1: typeof AB | boolean;
  var z1: string | typeof BC;
  
  
  //// [unionTypeEquivalence.js]
  var __extends = (this && this.__extends) || (function () {
      var extendStatics = Object.setPrototypeOf ||
          ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
          function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
      return function (d, b) {
          extendStatics(d, b);
          function __() { this.constructor = d; }
          d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
      };
  })();
  // A | B is equivalent to A if B is a subtype of A
  var C = (function () {
      function C() {
      }
      return C;
  }());
  var D = (function (_super) {
      __extends(D, _super);
      function D() {
          return _super !== null && _super.apply(this, arguments) || this;
      }
      D.prototype.foo = function () { };
      return D;
  }(C));
  var x;
  var x;
  // A | B is equivalent to B | A.
  var y;
  var y;
  // AB | C is equivalent to A | BC, where AB is A | B and BC is B | C.
  var z;
  var z;
  var z;
  var AB;
  var BC;
  var z1;
  var z1;
  