If you find a mistake, or something is unclear, please email
email@example.com so I can fix the text. We have earlier looked
at the values (nodes, primitives, and sequences) that XQuery
works with. In this article we will look more deeply into the
XQuery/XPath data model and type system. On the way we will
touch on a fair bit of background material, including XML
Schemas and XML infosets. The XQuery data model is based on the
XML Information Set standard (W3C Recommendation 24 October
2001, http://www.w3.org/TR/xml-infoset). It rather abstractly
defines the information content of an XML document as a document
item that contains nested element items, which in turn contain
namespace, attribute, character and other items. This is a
conceptual standard: It does not define any file formats or
programming interfaces, but rather it defines the interpretation
of an XML file. It is intended to be useful for defining other
XML-related standards, including the XQuery/XPath data model.
XML files that are different at the