- From: pat hayes <phayes@ai.uwf.edu>
- Date: Thu, 6 Feb 2003 13:26:38 -0600
- To: marc@jfcarrion.com
- Cc: Brian McBride <bwm@hplb.hpl.hp.com>, www-rdf-comments@w3.org
>--- Brian McBride <bwm@hplb.hpl.hp.com> wrote: >> At 03:12 24/01/2003 -0800, Marc Carrion wrote: >> >> [...] >> >> > That would be illegal if you don't have any >> other >> >information. But if you have had: >> > x rdf:type c . >> > c rdf:type rdfs:Abstract . >> > x rdf:type a . >> > a rdf:subClassOf c . >> > That would be correct. >> >> Built into RDF is the assumption that any subgraph >> of an RDF graph is a >> legal RDF graph. That's not likely to change >> anytime soon. >> > When using reification > _:xxx rdf:type rdf:Statement . > _:xxx rdf:subject <ex:a> . > _:xxx rdf:predicate <ex:b> . > _:xxx rdf:object <ex:c> . > would be true, but if we only have > _:xxx rdf:type rdf:Statement . > _:xxx rdf:subject <ex:a> . > _:xxx rdf:predicate <ex:b> . > that would not be a 'correct' model, I mean it's >going to have a wrong Resource of type Statement. No, not exactly. It is incomplete, not wrong. If I tell you that I have a head and two arms, you shouldn't conclude that I don't have any feet. The second graph *tells* you that _:xxx is of type Statement, so you (ought to) know that it *has* an object - they all do - but you just don't (yet) know what it is. RDF information is always potentially incomplete in this sense. > > The same when using Collections > _:c1 rdf:type rdf:List . > _:c1 rdf:rest _:c2 > which is a List without head, it's a correct Model >but an incorrect List No, it is a list and you don't (yet) know what its head is. You know it is a list, however, since the first triple tells you it is. RDF never gives you *definitions* in a strict sense, it only gives you *descriptions* (which might or might not be complete enough for you to figure out something you need to know, such as what the head of a list is.) Pat Hayes > > I was thinking that Abstract Classes could be >defined in the same way. > > Regards, > Marc > >===== >......\|||/................................................ > (. .) >-oOOo---0---oOOo------- >|marc_carrion@yahoo.es| >| ooO Ooo | >----( )--( )----------- > () () > >__________________________________________________ >Do you Yahoo!? >Yahoo! Mail Plus - Powerful. Affordable. Sign up now. >http://mailplus.yahoo.com -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes s.pam@ai.uwf.edu for spam
Received on Thursday, 6 February 2003 14:26:43 UTC