Extending XML-RL with some object-oriented features

XML is emerging as the dominant standard for data representation and exchange over the Web. XML-RL is a novel declarative ruled-based XML query language based on the high-level data model, XML-RL data model. First, we extend XML-RL data model with some important object-oriented features such as element hierarchy, multiple inheritance, overriding, blocking, conflict handling mechanisms and polymorphism, and then extend XML-RL to support polymorphic element and reference as well as inclusive element and reference