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Re: subproperty question

From: Arjohn Kampman <akam@aidministrator.nl>
Date: Thu, 25 Jan 2001 13:52:59 +0100 (MET)
Message-Id: <200101251252.NAA01190@spa.aidministrator.nl>
To: stefan@db.stanford.edu, horrocks@cs.man.ac.uk
Cc: www-rdf-interest@w3.org, sintek@smi.stanford.edu
> Stefan,
> 
> In general one wouldn't expect a sub-property of a transitive property
> to be transitive itself, e.g., parent as a sub-property of ancestor.
> 
> Ian

Related to this: I think you can state that, for a property to be transitive,
all of its superproperties have to be transitive too.

From the RDF/S spec: "If some property P2 is a subPropertyOf another more
general property P1, and if a resource A has a P2 property with a value B,
this implies that the resource A also has a P1 property with value B."

Now consider P2 to be a transitive property and you have the following
situation:

	X  --P2-->  Y  --P2-->  Z

In that case, X would also be related to Z through P2 and thus, as P1 is a
superproperty of P2, also through P1. Therefore P1 also has to transitive.

Please correct me if I'm wrong,


Arjohn
Received on Thursday, 25 January 2001 08:10:03 GMT

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