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Re: rdfs:subClassOf and metaclasses

From: Arjohn Kampman <arjohn.kampman@aidministrator.nl>
Date: Tue, 09 Jul 2002 11:53:39 +0200
Message-ID: <3D2AB2A3.80004@aidministrator.nl>
To: pat hayes <phayes@ai.uwf.edu>
CC: www-rdf-comments@w3.org

pat hayes wrote:
>>
>> rdfs10
>> If E contains:
>>   xxx [rdf:type] [rdfs:Class]
>> then add:
>>   xxx [rdfs:subClassOf] xxx
> 
> 
> This is already a consequence of the current closure rules.

To the best of my knowledge, the fact that a class is a subclass of
itself is only derived if there are cycles in the class hierarchy
(because of rule rdfs8). The rule above derives this for every class.

In the inferencer for Sesame [1], we have added *two* additional rules
to the inferencer: the rule stated above for reflexivity of the
subClassOf relation, and a similar rule for reflexivity of the
subPropertyOf relation. When we added these two rules to Sesame's
inferencer the number of inferred statements increased.

Regards,

Arjohn

[1] http://sourceforge.net/projects/sesame

-- 
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Received on Tuesday, 9 July 2002 05:54:14 GMT

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