- From: Benja Fallenstein <b.fallenstein@gmx.de>
- Date: Tue, 04 May 2004 20:10:12 +0200
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: pdawes@users.sourceforge.net, www-rdf-interest@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Peter wrote: |> "There exist triples with property P and an object of class foo," rather |> than "All triples with property P have objects of class foo," is a |> useful interpretation, I presume. | | But this is even expressible in RDF (at least for non-datatypes) | | _:x P _:y . | _:y rdf:type foo . True. If you have a query language, asking for whether there are any ?c such that ~ ?x P ?y . ~ ?y rdf:type ?c . isn't even harder than asking whether there are any ?c such that ~ P rangeIncludes ?c . OTOH, if you have a plain "Give me all triples (P, rangeIncludes, _)" interface, the second is much easier / more efficient than the first (where you have to iterate through all triples "(_, P, _)"). Phil, does Peter's way of stating this seem useful for what you want to do? |> | So, show us the inferences! |> |> ~ flabber x:schnack ghasted |> ~ ghasted rdf:type y:Ghostly |> |> =====> |> |> ~ x:schnack phil:rangeIncludes y:Ghostly | | This is *one* inference. What about the others? Are there any? I'm pretty sure that this is the one inference that Phil meant. x:schnack has an object of class y:Ghostly; therefore, x:schnack *can* have objects of class y:Ghostly. Yes, it's obvious, but it's useful b/c it tells you that it makes sense to show resources of class y:Ghostly as possible objects for x:schnack triples (or so I understand Phil). Cheers, - - Benja -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFAl9yEUvR5J6wSKPMRAgZPAJ4u6fRK0UQuNkfu0pS8HlD5dTMC4gCeMUg9 M0WXk1C0YCOuMHGR4hqrKDc= =gunT -----END PGP SIGNATURE-----
Received on Tuesday, 4 May 2004 14:10:57 UTC