- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Wed, 30 Jan 2002 11:42:45 -0600
- To: jos.deroo.jd@belgium.agfa.com
- Cc: w3c-rdfcore-wg@w3.org
>[what a subject to discuss...] > >Pat, > >[about http://www.coginst.uwf.edu/users/phayes/w3-rdf-mt-draft-J.html] > >If XL is really a *global* mapping What Im trying to convey is that XL is considered to be fixed outside the particular interpretation. It may be clearer to just omit that word 'global'. Fixed. > I assume that >each literal node is mapped into *one-and-ony-one* literal value Right, which is why we have to treat different occurrences as distinct nodes (or else rule out the P-ish class of schemes by fiat). >or have I misunderstood global? >then I don't see why >.. A literal node is a particular occurrence of a literal >.. literal nodes are unique to each graph. >.. several occurrences of a literal produce several rectangles with the same >label >.. literal nodes are not 'merged' in this way > >I think that the most convenient global mapping is > XL(literal-as-simple-name) = literal-as-simple-name >i.e. the identity mapping Well, yes, it is surely the most convenient from an MT point of view, but that would say that every literal denotes a string. I originally assumed that XL was defined on literals themselves (not occurrences of them), but I got mauled for doing that by Peter Patel-Schneider, if you recall, precisely because he wanted to have a datatype-sensitive mapping from literal occurrences to meanings. So I'm leaving the issue as open as I possibly can. XL might give every literal the same value, or it might give every single literal token in the universe a different value, choosing it by divine inspiration, or anything in between. This version of the MT just washes its hands of the problem and leaves it to some other box to decide. Obviously this is not a final account (as the document says in about ten places), but it is about the weakest assumption that I can possibly make for now. Most of the entailment stuff works even with this minimal an assumption, which is encouraging (since that means it will go on working no matter what we decide about datatyping.) Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Wednesday, 30 January 2002 12:48:44 UTC