- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Mon, 2 Oct 2006 10:14:14 +0100
- To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Sorry to be late, but there was some confusion about what was going on and then I hit the class part of the week. I think the status part should point to the issues list. """Costs: Tableau-based reasoners (at least, the Pellet Demo example 7) rely on the current, more expressive semantics to match implications that are not in a materializable RDF graph.""" No. Pellet uses BNodes as syntax for non-distinguished variables, as that's what we were told was the likely syntax for non-distinguished variables in SPARQL/DL. The semantics of *all* variables in SPARQL/ RDF is semi-distinguished. I thought the alternative proposal (e.g., from conversation with Jeen, Jorge and others) was to *drop* BNodes in triple patterns. That does solve all the problems of scope, meaning etc., but it means that certain combinations of the axes of distinguishedness will be harder to specify (but heck, we can always introduce syntax later). """@@ Now we are in CR, shouldn't this be deleted? Need chair's permission. The working group decided on this design and closed the disjunction issue without reaching consensus. The objection was that adding UNION would complicate implementation and discourage adoption. If you have input to this aspect of the SPARQL that the working group has not yet considered, please send a comment to public-rdf-dawg-comments@w3.org.""" I would like that to be deleted because it's confusing on several levels (e.g., why doesn't it apply in optional?) I don't particularly care that it'd done before pub, but it seems an easy enough move. I mean, it doesn't *change* anything! """Current conventions for DESCRIBE return an RDF graph without any specified constraints. Future SPARQL specifications may further constrain the results of DESCRIBE, rendering some currently valid DESCRIBE responses invalid. As with any query, a service may refuse to serve a DESCRIBE query."""" I have other comments, both editorial and substantial, but they are for post publication, I think. Cheers, Bijan.
Received on Monday, 2 October 2006 09:15:05 UTC