- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Fri, 2 Aug 2002 08:52:10 -0400
- To: David Allsopp <d.allsopp@signal.qinetiq.com>, public-webont-comments@w3.org
At 11:02 AM +0100 8/2/02, David Allsopp wrote: >With reference to the Feature Synopsis >http://www.w3.org/TR/owl-features/ : > >> differentIndividualFrom: Two individuals may be stated to be >>different from each other. For example, the individuals Frank and >>Deborah may be stated to be different from each other. From this, >>the reasoner can deduce that Frank and Deborah refer to two unique >>individuals. Thus, if the individuals Frank and Deborah are both >>values for a property that is stated to be functional (thus the >>property has at most one value), then there is a contradiction. >>Stating differences can be important in systems such as OWL (and >>RDF) that do not assume that individuals have one and only one >>name. For example, OWL with no additional information, will not >>deduce that Frank and Deborah refer to distinct individuals. > >Does this not lead to an explosion of properties in applications where >the majority of individuals do have unique names? I.e. for N individuals >we would require N(N-1)/2 differentIndividualFrom properties? > >Regards, > >David Allsopp David - this is a good point, and one which we are concerned about - it is on our issues list - see [1] for a discussion - we have not yet resolved this issue. -Jim H. [1] http://www.w3.org/2001/sw/WebOnt/webont-issues.html#I5.18-Unique-Names-Assumption-Support-in-OWL -- Professor James Hendler hendler@cs.umd.edu 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 240-731-3822 (Cell) http://www.cs.umd.edu/users/hendler
Received on Friday, 2 August 2002 08:52:16 UTC