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Re: [TF-ENT] A few comments on RDFS Entailment section

From: Birte Glimm <birte.glimm@comlab.ox.ac.uk>
Date: Tue, 6 Oct 2009 00:00:52 +0100
Message-ID: <492f2b0b0910051600n54b788c3u36cb6a005d256e61@mail.gmail.com>
To: "Seaborne, Andy" <andy.seaborne@hp.com>
Cc: SPARQL WG <public-rdf-dawg@w3.org>
2009/10/5 Seaborne, Andy <andy.seaborne@hp.com>:
> Birte,
> 1/ A simple example involving the RDFS vocabulary subClassOf or subPropertyOf would be useful in showing the reader what is covered.

I'll add that.

> 2/ Scoping Graph: it would be good to show the scoping graph in the discussion points.

I'm not sure where discussion points refers to, but I can add an
example for that too. It is just the same as for simple entailment
though, mainly a theoretical construct to make sure that blank node
IDs can be different from their ID in the active graph and the same ID
is only used in different answers when it indeed refers to the same
blank node.

> 3/ Boolean queries.
> Doesn't the same applies to any BGP with no named variables, so { [] :p :o } has an empty domain for sigma.

Yes, that's a Boolean query too in my understanding.

> 4/ DESCRIBE: The result of BGP matching are combined using the algebra and finally the query form generates the results.  I wasn't clear why DESCRIBE might be different.

Well, that is prefixed with a maybe to indicate that it could be an
option if we (the WG) think that this would be something to that users
would find useful.

> 5/ What's the "signature of the scoping graph" - I did a google search and the top relevant hit was Design:EntailmentRegimes itself.  Most were about signing graphs from the named graphs paper.

As Axel said, I mean vocabulary. That's the OWL term for vocabulary
and commonly used in logic. I can replace that for RDF/S and for OWL I
might explain that vocabulary and signature mean the same thing since
OWL folks are most likely more used to signature.

> 6/ It would be useful to include RDF-entailment even if only to give it an IRI.

I think Steve also mentioned that. We didn't do that so far because we
didn't want to repeat most stuff since RDF is very similar to RDFS,
just simpler. I'll think about whether it makes mre sense to have RDFS
first and then RDF as named regimes, but with a very short description
pointing out the differences to RDFS (which are minimal) or whether it
is better to keep the order RDF, RDFS, and proably D-entailement. In
any case, I'll name it.

Thanks for the comments,

>        Andy

Dr. Birte Glimm, Room 306
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Received on Monday, 5 October 2009 23:01:27 UTC

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