- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Mon, 16 Jun 2003 10:08:42 -0400
- To: Guus Schreiber <schreiber@swi.psy.uva.nl>, WebOnt WG <www-webont-wg@w3.org>
At 3:25 PM +0200 6/16/03, Guus Schreiber wrote: >Ron Alford wrote: >http://lists.w3.org/Archives/Public/public-webont-comments/2003May/0070.html > >> Hello, >> Since there is an owl:AllDifferent, why is there not an >>owl:AllSame? I have a need for it on my current project. It would >>be nice for it to have similar semantics to owl:AllDifferent. >> Thanks, >> - Ron Alford >> -- >> Ron Alford, KB0NUV >> http://volus.net/~ronwalf > >Ron, > >Thanks for your comment. > >We introduced a AllDifferent construct because of the exponential >growth of the number of differentFrom statements; see Sec. 6.3 of >OWL Reference [1] > >[[ >For ontologies in which the unique-names assumption holds, the use >of owl:differentFrom is likely to lead to a large number of >statements, as all individuals have to be declared pairwise disjoint. >]] > >The case is different for sameAs, because sameAs only leads to >linear growth of the number of statements. (due to the transitive >nature of sameAs, the statements "a sameAs b" and "b sameAs c" >already imply "a sameAs c"). > >Please respond, copying public-webont-comments@w3.org, as to whether >you are satisfied with this response. > >Guus Schreiber > > >[1] http://www.w3.org/TR/owl-ref/#AllDifferent-def Looks good. -- 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 *** 240-277-3388 (Cell) http://www.cs.umd.edu/users/hendler *** NOTE CHANGED CELL NUMBER ***
Received on Monday, 16 June 2003 10:08:47 UTC