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Re: Entailment regimes open issues

From: Axel Polleres <axel.polleres@deri.org>
Date: Mon, 15 Feb 2010 16:29:11 +0000
Cc: "Lee Feigenbaum" <lee@thefigtrees.net>, "Ivan Herman" <ivan@w3.org>, "SPARQL Working Group" <public-rdf-dawg@w3.org>
Message-Id: <F4B7788C-FFE3-421D-A6AD-BCAAC26DD68C@deri.org>
To: Birte Glimm <birte.glimm@comlab.ox.ac.uk>

Well, these (32 and 34) are definitly separate issues, but I guess we agree on that...

As for issue-34, I agree that we can close the issue if the single goal is that the
behaviour is well defined... we have to be aware though, that results may not always 
and for everybody will be intuitive: in fact, although every current implementation 
probably treats bnodes just as constants under a kind of unique names assumption 
in aggregates like count (does anybody do anything different?) there would 
be alternative ways to handle bnodes in aggregates, like
Alternative1: ignoring bnodes for aggregates (could be viewed reasonable conceptually, IMO)
Alternative2: for entaiment regimes like OWL which have an explicit notion of equality/inequality
              counting could be expected to just return the number of those 
              - Alternative2a: known to be different
              - Alternative2b: not known to be the same

Before just closing the issue, I would at least think that a sentence or two (and maybe examples)
should be added that clarify that those behaviors are NOT provided by the current semantics.

Axel


On 11 Feb 2010, at 19:05, Birte Glimm wrote:

> Just 32 means 34 I think:
> [ISSUE 34]: How do entailment regimes interaction with aggregates,
> grouping, and blank nodes?
> Birte
> 
> On 11 February 2010 14:16, Lee Feigenbaum <lee@thefigtrees.net> wrote:
> > On 2/8/2010 2:02 AM, Ivan Herman wrote:
> >>
> >> I certainly agree with closing issues #28, #32, #40, #42.
> >>
> >> I would propose to leave #43 for a while to see how the SD work evolves.
> >> I predict that what you write below is true, but maybe discussions on SD
> >> will allow for a finer granularity...
> >
> > I will close issues 28, 32, 40, and 42 if there is no concerns raised within
> > the next 7 days.
> >
> > Let's include issue 43 in our next TC discussion of service description.
> >
> > Lee
> >
> >
> >
> 
> 
> 
> --
> Dr. Birte Glimm, Room 306
> Computing Laboratory
> Parks Road
> Oxford
> OX1 3QD
> United Kingdom
> +44 (0)1865 283529
> 
> 
Received on Monday, 15 February 2010 16:29:46 GMT

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