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Querying for Namespaces


This mechanism enables users even to query for namespaces (concrete URIs not aliases) and to provide variables in namespaces. For instance, the following query asks for all namespaces X that contain a concept person.

?- ?X [_localName->Person, _namespace->?N].

The following inference rule integrates knowledge from different ontologies using the namespace mechanism (and a so called Skolem-function).

person(?Name)[?Attr -> ?Value] :-

         (EXIST ?X

                 ?X:finance#Person[?Attr -> ?Value, finance#name -> ?Name] OR

                 ?X:cars#Person[?Attr -> ?Value, cars#name -> ?Name]).