text: //// [typeGuardOfFormInstanceOfOnInterface.ts]
  // A type guard of the form x instanceof C, where C is of a subtype of the global type 'Function' 
  // and C has a property named 'prototype'
  //  - when true, narrows the type of x to the type of the 'prototype' property in C provided 
  //    it is a subtype of the type of x, or
  //  - when false, has no effect on the type of x.
  
  interface C1 {
      (): C1;
      prototype: C1;
      p1: string;
  }
  interface C2 {
      (): C2;
      prototype: C2;
      p2: number;
  }
  interface D1 extends C1 {
      prototype: D1;
      p3: number;
  }
  var str: string;
  var num: number;
  var strOrNum: string | number;
  
  var c1: C1;
  var c2: C2;
  var d1: D1;
  var c1Orc2: C1 | C2;
  str = c1Orc2 instanceof c1 && c1Orc2.p1; // C1
  num = c1Orc2 instanceof c2 && c1Orc2.p2; // C2
  str = c1Orc2 instanceof d1 && c1Orc2.p1; // C1
  num = c1Orc2 instanceof d1 && c1Orc2.p3; // D1
  
  var c2Ord1: C2 | D1;
  num = c2Ord1 instanceof c2 && c2Ord1.p2; // C2
  num = c2Ord1 instanceof d1 && c2Ord1.p3; // D1
  str = c2Ord1 instanceof d1 && c2Ord1.p1; // D1
  var r2: D1 | C2 = c2Ord1 instanceof c1 && c2Ord1; // C2 | D1
  
  //// [typeGuardOfFormInstanceOfOnInterface.js]
  // A type guard of the form x instanceof C, where C is of a subtype of the global type 'Function' 
  // and C has a property named 'prototype'
  //  - when true, narrows the type of x to the type of the 'prototype' property in C provided 
  //    it is a subtype of the type of x, or
  //  - when false, has no effect on the type of x.
  var str;
  var num;
  var strOrNum;
  var c1;
  var c2;
  var d1;
  var c1Orc2;
  str = c1Orc2 instanceof c1 && c1Orc2.p1; // C1
  num = c1Orc2 instanceof c2 && c1Orc2.p2; // C2
  str = c1Orc2 instanceof d1 && c1Orc2.p1; // C1
  num = c1Orc2 instanceof d1 && c1Orc2.p3; // D1
  var c2Ord1;
  num = c2Ord1 instanceof c2 && c2Ord1.p2; // C2
  num = c2Ord1 instanceof d1 && c2Ord1.p3; // D1
  str = c2Ord1 instanceof d1 && c2Ord1.p1; // D1
  var r2 = c2Ord1 instanceof c1 && c2Ord1; // C2 | D1
  