3. This paper extends XML RL which is a rule based XML query language based on higher level data model, with some important object oriented features such as element hierarchy, multiple inheritance, polymorphism.
Engineer fred = new Engineer(Fred, Smith, 12.0, 8.0); Manager ann = new Manager(Ann, Brown, 1500.0); SalesManager mary= new SalesManager(Mary, Kate, 2000.0); // Polymorphism, or late binding Employee[] employees = new Employee[3]; employees[0]= fred; employees[1]= ann; Java knows ...