- From: Dan Connolly <connolly@w3.org>
- Date: Wed, 12 Nov 2003 17:47:39 -0600
- To: pat hayes <phayes@ihmc.us>
- Cc: w3c-rdfcore-wg@w3.org, Graham Klyne <gk@ninebynine.org>
On Wed, 2003-11-12 at 17:13, pat hayes wrote: > Guys, in the interests of full disclosure, here's a summary of the > changes made to the semantics document in the last few days. I > actually think that this is now *all*. Hmm... no pointer to the text... using the one you've given recently, I find... $ HEAD http://www.ihmc.us/users/phayes/RDF_Semantics_LC2.5.html 200 OK Date: Wed, 12 Nov 2003 23:36:40 GMT ETag: "58d0c8-3b7ea-3fb28432" Content-Length: 243690 Content-Type: text/html Last-Modified: Wed, 12 Nov 2003 19:04:18 GMT Hmm... I see the same text now that I saw when you said... <patH> Dan, you still there? The version now at http://www.ihmc.us/users/phayes/RDF_Semantics_LC2.5.html is completely post-terHorst and has an updated changes log. You can run with that one as far as Im concerned right now: thats my final Wednesday effort.. I checked it in at that point... revision 1.46.2.6 date: 2003/11/12 19:15:48; author: connolly; state: Exp; lines: +415 -365 That version doesn't become available at http://www.w3.org/TR/2003/WD-rdf-mt-20031010/ unless/until somebody merges that branch into the head. Brian, feel free to do so. Pat, does appendix D say pretty much what you're saying here? Ah... I guess it does... > 1. Section subheadings added/changed as per > http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Nov/0051.html > > 2. "name" now includes plain literals, so vocabularies (= sets of > names) also may contain plain literals. They are not obliged to, so > all old vocabularies are still new vocabularies. > > 3. 'proper instance' now allows substitution of a plain literal for a > bnode. > > 4. semantic conditions on simple interpretations of a vocabulary V > are now restricted to the plain literals in V (as they were formerly > for the URIs and typed literals. ) > > The effect of 2-4 is that all referring expressions (URIrefs and > literals) are treated uniformly, and interpretations of a graph are > only obliged to interpret the symbols which occur in the graph. All of > this is conventional and makes the RDF MT more 'normal'. For > justification of why it was needed, see Herman's recent comment on the > failure of the RDFS entailment lemma proof > http://lists.w3.org/Archives/Public/www-rdf-comments/2003OctDec/0150.html (see "To give an example, let A be a URI reference" et seq) > No changes to any test cases or entailments arise. > > 5. minor editorial changes arising from 2-4 above, eg "name or plain > literal" -> "name" in several places, and the example in figure 1 now > has the literals listed in its vocabulary explicitly. > > 6. Text added in 1.1 Technical note (Informative): > "Readers who are familiar with conventional logical semantics may find > it useful to think of RDF as a version of existential binary > relational logic in which relations are first-class entities in the > universe of quantification. Such a logic can be obtained by encoding > the relational atom R(a,b) into a conventional logical syntax, using a > notional three-place relation Triple(a,R,b); the basic semantic > described here can be reconstructed from this intuition by defining > the extension of y as the set {<x,z> : Triple(x,y,z)} and noting that > this would be precisely the denotation of R in the conventional > Tarskian model theory of the original form R(a,b) of the relational > atom. This construction can also be traced in the semantics of the > Lbase axiomatic description [LBASE]." Is that supposed to fall under "Several pieces of explanatory prose have been added, in response to requests for clarification."? OK, I'll buy that. > This point was raised by at least 3 people at ISWC and in other > working groups, so I thought it might be worth drawing attention to. > > 7. Other minor editorial suggested by Herman, eg "and A(E) is defined" > added in the third semantic condition table. None of these change > meanings, only clarify or correct errors. > > 8. The definitions of the Hebrand interpretations in the proof > appendix have been simplified somewhat, since they are no longer > required to interpret all plain literals. The definition of the 'sur' > construction in the RDFS entailment lemma proof has been clarified; > several explanatory paragraphs have been added to make the proofs > easier to follow, and some typos corrected (which also helps, of > course.) Again, for discussion and motivation see Herman's recent > email comments. > > 9. As well as the above, the change log notes the > _:x rdf:type rdfs:ContainerMembershipProperty . > empty entailment case discussed in earlier emails. OK, good. > Pat -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Wednesday, 12 November 2003 18:47:41 UTC