- From: pat hayes <phayes@ai.uwf.edu>
- Date: Thu, 1 May 2003 11:20:48 -0500
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: www-rdf-comments@w3.org
>From: pat hayes <phayes@ai.uwf.edu> >Subject: Re: pfps-08 last call comment on typed literals >Date: Tue, 29 Apr 2003 16:51:43 -0500 > >> Peter, >> >> In >> >> http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0087.html >> >> you raised a last call comment on the RDFCore WD's which was recorded as: >> >> http://www.w3.org/2001/sw/RDFCore/20030123-issues/#pfps-8 >> >> The WG has previously decided to reject this comment: >> >> http://lists.w3.org/Archives/Public/www-rdf-comments/2003JanMar/0537.html >> >> However, subsequent work has suggested that we reconsider this decision. >> >> The treatment of XML literals currently proposed would retain the >> 'simple' version (in which the literals are treated as a special >> lexical form) in RDF and RDFS interpretations, but treat >> rdf:XMLliteral as denoting a datatype object in D-interpretations. >> >> This would support the entailment you refer to in all datatyped >> interpretations, for typed literals which do not contain language >> tags. It would not, however, support an inference of the following >> form (in Ntriples): >> >> ex:bar owl:sameIndividualAs rdf:XMLLiteral . >> ex:s ex:p "foo"@tag^^rdf:XMLLiteral . >> |- >> ex:s ex:p "foo"@tag^^ex:bar >> >> since the RDF semantic conditions require that language tags are >> ignored in non-XML typed literals. >> >> Please let us know whether this would be acceptable. >> >> Pat Hayes > >I do not view this as a satisfactory solution to my issue. > >I do not even view it as in any way better than the previous state of >affairs. > OK; but that is rather a strong rejection, which leaves me rather at a loss how to proceed. In earlier correspondence (off-list) you seemed to indicate that you found the current treatment of datatypes satisfactory; admittedly at that time our attention had not been drawn to the above case. There seem to be many ways that OWL could accommodate to this situation. For example, I gather than Webont is likely to recommend that rdf:XMLLiteral be deprecated in OWL. If so, it would be harmless for OWL to deprecate, or even forbid, the use of lang tags in literals (since they play no role anywhere but for XMLLiteral) , and then the above would seem to solve the problem you raised in your original comment. Another, less draconian, solution would be to forbid any OWL assertion which equates anything to rdf:XMLliteral (which, because of its special role in the RDF syntax, has to be treated as an opaque identifier rather than a simple name.) Such equations would be prohibited in OWL-DL and OWL-Lite, in any case. Your strong rejection, therefore, leads me to believe that there might be other problems than the ones I had diagnosed from your original comment. Could you indicate which aspects of this are you are unsatisfied with? In particular, if the treatment of lang tags were made uniform across all typed literals, so as to support substitution of equals anywhere in the RDF literal syntax in datatyped interpretations, would that be sufficient? There are several ways we could try to arrange that to happen, but it would save some work if you could tell us what your criteria for success would be, so that we can avoid unsatisfactory designs by a process more efficient than Darwinian selection. Or would you insist on XML literal typing being done in a semantically uniform way between undatatyped and datatyped RDF interpretations? I do not think we can accommodate the latter requirement, so if that is what you find unsatisfactory then there may be no point in attempting to satisfy you on this particular issue. Pat -- --------------------------------------------------------------------- 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, 1 May 2003 12:20:53 UTC