text: <rtl code>
  var m1 = function (){
  function Base(){
  }
  function Derived(){
  	Base.call(this);
  }
  RTL$.extend(Derived, Base);
  return {
  	Base: Base,
  	Derived: Derived
  }
  }();
  var m2 = function (m1){
  var b = new m1.Base();
  var d = new m1.Derived();
  
  function isDerived(b/*VAR Base*/){
  	var result = false;
  	var $case1 = b;
  	if ($case1 instanceof m1.Derived){
  		result = true;
  	}
  	return result;
  }
  RTL$.assert(!isDerived(b));
  RTL$.assert(isDerived(d));
  }(m1);
  