W3C home > Mailing lists > Public > public-vocabs@w3.org > March 2014

Re: How to avoid that collections "break" relationships

From: Ruben Verborgh <ruben.verborgh@ugent.be>
Date: Mon, 31 Mar 2014 18:26:22 +0200
Cc: Markus Lanthaler <markus.lanthaler@gmx.net>, Pat Hayes <phayes@ihmc.us>, public-hydra@w3.org, Linked Data community <public-lod@w3.org>, W3C Web Schemas Task Force <public-vocabs@w3.org>, Dan Brickley <danbri@danbri.org>
Message-Id: <975C6D5B-08FC-44A6-8AC5-EB96ECCF1215@ugent.be>
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
Peter,

Please, let's get the discussion back
to what we want to achieve in the first place.
Right now, the solution is being evaluated
on a dozen of other things that are not relevant.

Proposal: let's discuss the whole abstract RDF container thing on public-lod@w3.org,
and solutions to make clients work at public-hydra@w3.org.

We're talking here about making clients able to get the members of something.
Yes, they will need to interpret some properties.
Just like an OWL reasoner needs to interpret owl:sameAs,
a Hydra client needs to interpret hydra:member.
That is how applications work.

In no way, defining a vocabulary is extending RDF.
RDF is a framework. I'm not adding to the framework.
I'm proposing a simple property
    hydra:memberOf owl:inverseProperty hydra:member.
If you really don't like me introducing a property,
here's an alternative way of saying the same thing:

   </people/markus> foaf:knows _:x.
   </people/markus/friends> hydra:member _:x.

There you go. hydra:member was already defined,
I'm not inventing or adding anything.

> You want to depend on a particular reading of this non-RDF predicate, and have this reading trigger inferences.

No I don't want any of that. Why do think I'd want that?
Where did I say I want inferences? Where do I need them?

Also, how could it possibly be a non-RDF predicate?
RDF simply defines a predicate as an IRI [1].

> Again making a significant addition to RDF.

When did defining a vocabulary become adding to RDF?

> Which is precisely my point.  You are using OWL, not just RDF.  If you want to do this in a way that fits in better with RDF, it would be better to add to the syntax of RDF without adding to the semantics of RDF.

…but this has _never_ been about extending RDF in any way,
nor has it been about only using RDF or only using OWL.
We don't want any of that. We want:

1. Having a way for clients to find out the members of a specific collection
2. Not breaking the RDF model while doing so

The proposed solution achieves both objectives.

Best,

Ruben

[1] http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/#dfn-predicate
Received on Monday, 31 March 2014 16:26:57 UTC

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