Logical foundation for updating XML

With the extensive use of XML in applications over the Web, how to update XML data is becoming an important issue because the role of XML has been expanded beyond traditional applications in which XML is used for data representation and exchange over the Web. Several languages have been proposed for updating XML data, but they have two main drawbacks. One is these updating languages are based on low-level graph-based or tree-based data models so that update requests are thus expressed in a nonintuitive and unnatural way and update statements are too complicated to comprehend. The other is there is still no consensus about the logical foundation for XML updates. This paper presents a declarative language for updating XML data based on a high-level data model and systemically describes its semantics.