Introduction

XINDALOG is a project whose aim is to use logic programming as query language for the Web and the Semantic Web.

In this framework, we have studied how to implement the XPath and the XQuery languages on logic programming. With this aim, we have described how to represent XML documents into logic programming by means of facts and rules. In addition, we have proposed a translation of XPath and XQuery into a logic program, from which specific goals are able to compute the answers of XPath and XQuery queries. Such answers for logic goals can be used for the building of the output XML document of a XPath/XQuery query. There are two  kinds of translations.  One  of them  specializes the logic program with respect to the XPath  query by using a  Magic -set  based transformation, and therefore  it evaluates the logic program in bottom-up.  The second  technique  specializes the logic program with respect to the XPath query by  removing  and reordering predicates, and it evaluates the logic program  in a top-down fashion.

Recently, we have proposed an extension of the XQuery language for querying RDF documents with the aim to incorporate and handle semantic information about Web data. Such extension of XQuery allows to query XML/RDF documents. We have proposed an implementation of such a language in logic programming. Our intention is to extend again the language for the handling of more complex semantic information by means of OWL, and study how to implement it in logic programming.

BOTTOM UP WEB PROTOTYPE
TOP DOWN WEB PROTOTYPE

For more information about XML and XPath can be found here and here.