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On Fri, Oct 24, 2003 at 10:19:19AM -0700, Jeff Lowery wrote: > So if you took the verbiage of the Data Model, distilled it into formal > symbolic description in a suitably expressive language, and then used that > for validating purported Xpath/Xquery data models, whould that be a called a > schema? Possibly but it wouldn't be a very useful one. See the XML Query 1.0 and XPath 2.0 Formal Semantics document [1] if you are after a more formal description of processing instnces of the XPath data model. You could build an instance of the XPath Data Model from anything you liked (a relational database table is a not unlikely example) as long as you implemented the necessary properties described in [2]. In some sense, anything that constrains or describes the structure of a formal system can be called a Schema, but in the context of xml-dev I think people usually mean a Schema that constrains or describes a family of XML documents. Your example would not be a Schema over XML, but instead it would be a Schema of XML Data Model Instances, which is not at all the same thing. Liam [1] http://www.w3.org/TR/xquery-semantics/ [2] http://www.w3.org/TR/xpath-datamodel/ -- Liam Quin, W3C XML Activity Lead, http://www.w3.org/People/Quin/
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