If you want a hydra solution, then you should do whatever is needed to make it
a hydra solution.
In actuality, defining things like owl:sameAs is indeed extending RDF.
Defining things in terms of OWL connectives also goes beyond RDF. This is
different from introducing domain predicates like foaf:friends. (Yes, it is
sometimes a bit hard to figure out which side of the line one is on.)
peter
On 03/31/2014 09:26 AM, Ruben Verborgh wrote:
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-hy...@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
