Based on grammar analysis´s expressiveness among the different XML-Schema Languages

The XML (eXtensible Markup Language) determines the basic format for data exchange in the web. DTD (Document Type Definition) is the common schema language. The advantages are especially because of its structure and the simplicity of its presentation. But DTDs are limited: They have only a few set of basic types and they miss the expressiveness to execute the context dependent declaration of elements. The XML-Schema Definition (XSD) is supported by W3C (World Wide Web Consortium) and thus gets the most attention. This Schema language was developed to avoid the disadvantages of DTD. Although it clears the most disadvantages of DTD, another one, the extended DTD (eDTD), has even a stronger expressiveness. In this paper we will use grammar analysis to proof the expressiveness of the different XML-Schema Languages.