Re: Event Updated: RDF-star WG biweekly meeting

Dear Enrico,

I have some remarks for the semantics here.
Am 27.08.2024 um 20:19 schrieb Franconi Enrico <franconi@inf.unibz.it>:

RDF-star WG biweekly meeting
29 August 2024, 12:00 -12:55 America/New_York
Agenda
(…)
2 Proposed resultion by Semantics TF 3

This was the approved proposed resolution by the TF:
Any IRI used as the predicate of a triple whose object is a triple term denotes an instance of the denotation of rdf:ReificationProperty.
The actual impact of this resolution on the baseline is formalised in:
https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22alternative-baseline%22#rdf-semantics


This is a minor point, but I would like to have the semantics here more in line with rdf:Property (https://www.w3.org/TR/rdf11-mt/#rdf-interpretations). We can change one of the two definition, but coming from RDF as it is, I would not want to make it depend on a syntactic representation of a resource that the predicate used with it is a reification property. So, <<(:s :p :o)>> and :n could be mapped by [I+A] to the exact same resource, and thus the triples

:s1 :p1 <<(:s :p :o)>>.

and

:s1 :p1 :h.

Would have the same meaning, but only the first would entail that :p1 is a reification property. Or to make it more crisp by adding owl:sameAs:

:s1 :p1 :h.
:h owl:sameAs <<(:s :p :o)>>.

would not entail (or not directly entail, only by going back to syntax)

:p1 a rdf:reificationProperty.

We could easily fix that by introducing a set IT as the range of RE. Then we would get the same kind of condition we get for properties in RDF semantics where the set IP is used and the construct would still work. So, I still like the idea.



3 Proposal for next week's discussion


  1.  We should discuss whether or not to limit the (abstract) syntax to have triple terms only in object position.
  2.  I believe that we have had enough discussions to take a final decision on whether or not to extend RDFS with rdfs:assert, as defined in:
https://github.com/w3c/rdf-star-wg/wiki/Extending-the-baseline-with-%22asserted%22-stuff





I see two problems with


[I+A](t) = TRUE   iff   <[I+A](t.s), [I+A](t.o)> ∈ IEXT([I+A](t.p)) and
                        [I+A](t.o) = TRUE    if   t.p = rdfs:states  and t.o is a triple term

1. It is ambiguous because the first [I+A](t.o) refers to the interpretation of t.o as a term and the second [I+A](t.o) refers to the triple t.o.

2. The iff is problematic, because it excludes all other kinds of triples. I would expect that a triple can also be true if it has a dedicate other than rdf:states

Having said that, I also think that the intended behavior as indicated in the examples was exactly what Thomas proposed.

Kind regards,
Dörthe




cheers
—e.

RDF-star WG biweekly meeting

29 August 2024, 12:00 -12:55 America/New_York

Agenda

  1.  Approval of minutes from the last two meetings: 1<https://www.w3.org/2024/08/15-rdf-star-minutes.html>, 2<https://www.w3.org/2024/08/22-rdf-star-minutes.html>
  2.  Proposed resultion by Semantics TF 3<https://www.w3.org/2024/08/23-rdf-star-minutes.html>
  3.  Proposal for next week's discussion
  4.  Review of pull requests, available at 4<https://github.com/orgs/w3c/projects/20/views/4>
  5.  Issue Triage, available at 5<https://github.com/orgs/w3c/projects/20/views/5>
  6.  Any Other Business (AOB), time permitting

Scribe: Kellogg, Gregg (alternate: Seaborne, Andy)

Next week's scribe: Seaborne, Andy (alternate: Williams, Gregory)


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