- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Tue, 6 May 2003 07:32:25 -0400
- To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
- Cc: webont <www-webont-wg@w3.org>
>(copied from rdf core) >> I personally agree >> with Tim that these (type List) triples are redundant, and I would >> bet that the OWL stuff, even if it does need them, could be trivially >> rewritten so that it did not. I was hoping that we could get back to >> Peter and find out whether he thought the problem was serious. > > >Peter punts the problem back to me - since I am the most recent person on >record as arguing for type triples in general (in OWL DL). > >Here are my thoughts: > >1: this is merely aesthetic either way > People who don't/do want the type triples can have what they want simply >by not using the rdf:parseType="Collection" syntax (whichever way we >decide). > >2: the triples *are* redundant > It is easy to automatically add them; or for that matter, automatically >remove them. > >3: the construct was added for OWL, and so the aesthetic judgement as to >whether they should be there or not in the convenience >rdf:parseType="Collection" syntax, should be made by WebOnt. > >4: Given that in OWL DL and OWL Lite many type triples are needed, it is, in >my opinion, more aesthetic, to have these type triples also for Lists. The >need for type triples is principally to distinguish the various types of >user defined in Property in OWL Lite and OWL DL. > >Jeremy Jeremy - I concur w/you. Also, I think that removing these triples, and then having to explain the differences everywhere would be painful -- would require us to carefully go through S&AS and other documents making sure that everywhere we discuss typing or lists we mention this. I think it would be easier for RDF to leave these in then for us to remove them - however, I also agree it is not a make or break issue since they are easily added. here's a question -- if RDF allows these triples and OWL requires them, does that cause a layering issue? That is, could RDF say "SHOULD" or "MAY" instead of must, with a note that for compatibility with OWL it is recommended? Collections without the rdf:list will still be in OWL Full, and it would be an easy thing to add these triples into a "MakeOwlDL" program that would read an RDF document and generate a legal OWL DL graph for it (something I'm assuming will need to exist to add annotations and the like to RDF "data" documents) -JH -- 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 Tuesday, 6 May 2003 07:32:39 UTC