XML queries are usually expressed by means of XPath expressions identifying portions of the selected documents. An XPath expression defines a way of navigating an XML tree and ret...
XML languages, such as XQuery, XSLT and SQL/XML, employ XPath as the search and extraction language. XPath expressions often define complicated navigation, resulting in expensive...
Given a document D in the form of an unordered labeled tree, we study the expressibility on D of various fragments of XPath, the core navigational language on XML documents. We gi...
Marc Gyssens, Jan Paredaens, Dirk Van Gucht, Georg...