- From: Patrick Stickler <patrick.stickler@nokia.com>
- Date: Sun, 16 Jun 2002 17:19:09 +0300
- To: Pat Hayes <phayes@ai.uwf.edu>, RDF Core <w3c-rdfcore-wg@w3.org>
- Message-ID: <B932790D.16DDB%patrick.stickler@nokia.com>
Thanks, Pat, for making this effort, and while I think we agree on ultimately what the interpretation of literals should involve, I'm going to go one step further and simply pour gasoline on the stake and set it alight (see below). On 2002-06-14 6:04, "ext patrick hayes" <phayes@ai.uwf.edu> wrote: > Everything else works as before; graphs are tidy on literal nodes. > > What follows? First, note that this allows the literal to 'indicate' > a different value than it denotes (ie something other than itself), > and a different one of those in each triple. So although it is indeed > true that "10" denotes "10" in this graph, nevertheless the meanings > of the the two triples containing that literal can refer to different > things than "10". This means in turn that the entailment rules need > to be modified slightly: it isn't valid to existentially generalize > on literals. For example, the above graph does NOT entail > > <ex:Jenny> <ex:age> _:x . > _:f <dc:title> _:x . > _:f <rdf:type> <ex:movie> . > > It does, however, entail > > <ex:Jenny> <ex:age> _:x . > _:f <dc:title> _:y . > _:f <rdf:type> <ex:movie> . > > via the graph below. It seems to me that you are defining untidy literals without admitting that literals are untidy. Don't get me wrong, I'm all for a MT that allows the inline idiom to denote values rather than lexical forms, but if we're going to have untidy interpretation for literals yet not make them untidy, we miss the benefit of being able to use RDFS range semantics for defining global datatyping contexts. Thus, it's like having your cake but being forced to eat it through a straw. If literals have untidy interpretation (and I think they should) then we can also simply say that the literal node denotes the value and then use rdfs:range to assert global datatyping for the inline idiom and define datatyping in terms of RDFS semantics. > What this is all about, of course, is tidyness; we can't assume that > a tidy literal indicates the same thing in each triple. Sounds like just saying that literals are untidy. Apologies in advance, but I'm going to get "right in the face" of the WG and strongly insist that we got it completely wrong when we decided that literals were tidy, and that all the MT gymnastics that has to happen to make things work the way people are actually using datatyping is getting rather pathetic. We should stop, back up, make literals untidy, and use RDFS semantics "as God intended" to define datatyping of literal values, adding the necessary definitions for the special characteristics of datatype classes and their relationship to RDFS class extension and be done with it. > Then all the > current idioms work out as they do now, except that the in-line idiom > is datatype-sensitive, as Patrick wants. Well, I'd rather say that it's what users of DC, CC/PP, and other applications already *use* (not simply what I want, though that is true). -- I formally call for the WG to consider replacing the stake in the ground with the earlier simpleDatatypes2 which is grounded in RDFS semantics and reflects common perceptions and expectations regarding RDF datatyping as it relates to the inline idiom and introduces less vocabulary and brings datatyping into full compatability with RDF typing proper. It's far simpler, clearer, and reflects what users are doing. See the attached materials. I would like to see this addressed during the F2F when datatyping is discussed. Regards, Patrick -- Patrick Stickler Phone: +358 50 483 9453 Senior Research Scientist Fax: +358 7180 35409 Nokia Research Center Email: patrick.stickler@nokia.com
Attachments
- application/octet-stream attachment: Comparison.html
- application/octet-stream attachment: entailments.n3
Received on Sunday, 16 June 2002 10:14:54 UTC