Re: Revisiting RDF-star semantics (was Re: Why is the RDF-star working group standardising RDF 1.2 and SPARQL 1.2?)

Dear Antoine,

We had discussions at the very beginning of the RDF-star working group whether or not blank nodes are to be transparent. If we accept total opacity, your solution would be indeed very nice and - as you said - we could still add a condition to your mapping that two isomorphic rdf-star triples should map to the same resource. I just understood from the previous discussions in this group that we would like to have that:

<< _:a :p :o >> :x :y . _:a :p :o.

entails

<< _:b :p :o >> :x :y . _:b :p :o.

and does not entail

<< _:b :p :o >> :x :y . _:a :p :o.

Is that still the case?

I think the most critical cases are the ones were we also assert the quoted triple. As Peter mentioned, these blank nodes are what makes this whole modeling complicated (and of course the literals, but that is a separate story).

Kind regards,
Dörthe




Am 31.01.2023 um 13:45 schrieb Antoine Zimmermann <antoine.zimmermann@emse.fr<mailto:antoine.zimmermann@emse.fr>>:

Le 27/01/2023 à 20:57, Peter F. Patel-Schneider a écrit :
This has to be done carefully if blank nodes are to be transparent.

As described in my previous email, my proposal is to make everything in an embedded triple completely opaque.

Just like:

<http://x.eu/?s=_%3Ab&p=http%3A%2F%2Fx.eu%2Fp&o=%2201%22%5E%5Exsd%3Aint>

could be a way of referring to, or being related to, the triple:

_:b <http://x.eu/p> "01"^^xsd:int .

and a system could extract the parameters of the URI to do interesting things with them, but as the semantics is concerned, there is no a priori relation between the URI and the triple, nor between the URI and the components of the triple.

--AZ

peter
On 1/27/23 13:30, Pierre-Antoine Champin wrote:
On 27/01/2023 11:49, Antoine Zimmermann wrote:
(*) RDF-star basic semantics would be defined on any RDF-entailment regime by adding a mapping IT from embedded triples to the set of resources IR. Under this basic semantics, embedded triples simply act as distinct names, as if they were IRIs. This does not preclude extensions where the internal structure of the embedded triples makes a difference.
I like that.

Would you mind developing this further?

  pa

PS: also, the https://github.com/w3c/rdf-semantics repo is available for PRs ;-)


--
Antoine Zimmermann
ISI - Institut Henri Fayol
École des Mines de Saint-Étienne
158 cours Fauriel
42023 Saint-Étienne Cedex 2
France
Tél:+33(0)4 77 42 66 03
https://www.emse.fr/~zimmermann/