- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Thu, 18 Dec 2003 07:44:20 -0500
- To: "Bernard Vatant" <bernard.vatant@mondeca.com>, public-webont-comments@w3.org
At 10:38 +0100 12/18/03, Bernard Vatant wrote: >I need some help from experts in logic ... > >I've sent a few days ago a message about "TexasThings" example in OWL Guide >(see below), where the interpretation of allValuesFrom seems wrong to me. >Without answer so far from there, I push the question here. > >Suppose I have the following - more enlightening to me at least than Texas >Things :)) Bernard - you are right that someValuesFrom is the appropriate thing to use -- this is a common confusion, and it is embarassing that we missed it in the Guide owl:someValuesFrom requires at least one value meeting this restriction be there (i.e. it is like "there exists" - it mandates that one exists) - there can be more than one value with the property, or other values without the property, but at least one if there. owl:allValuesFrom does not require a value be there, but does require that if there are one or more values of this property they must all meet this restriction good catch -JH -- Professor James Hendler http://www.cs.umd.edu/users/hendler Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-277-3388 (Cell)
Received on Thursday, 18 December 2003 07:46:11 UTC