- From: Thomas Lörtsch <tl@rat.io>
- Date: Tue, 13 Dec 2022 14:25:32 +0100
- To: Pierre-Antoine Champin <pierre-antoine@w3.org>
- Cc: Souripriya Das <souripriya.das@oracle.com>, "public-rdf-star-wg@w3.org" <public-rdf-star-wg@w3.org>
How about :A a :Lie . << :A a :Lie >> owl:sameAs :Aq . :Aq a :Lie . Doesn’t that overcome RDF-star's syntactic safe guard against paradoxes? And if it does - I’m not a logician, so I’m not sure - aren’t the consequences even worse for RDF-star than for RDFn, as the paradox targets all occurrences of type << :A a :Lie >>, not only one instance as in RDFn’s case. I haven’t fully understood how the RDF 1.x semantics tackles this topic [0] but as I said before my intuition is that going the way of occurrences (which in my understanding is a more generic term for both instances and subtypes, which - see OWL punning - are rather application specific categories) opens the same venue: interpreting a statement as a concrete occurrence of the type instead of as the type itself (as the RDF-star semantics proposes) separates the two, puts the occurrence in the extension of the type, and thereby avoids paradoxes in the semantics already. Thomas [0] https://www.w3.org/TR/rdf-mt/#technote > On 9. Dec 2022, at 08:15, Pierre-Antoine Champin <pierre-antoine@w3.org> wrote: > > Thanks Souri, > > I added a link to the slides in the minutes of the call where you presented them. > https://www.w3.org/2022/11/17-rdf-star-minutes.html > > A few remarks about slides 8 and 9: > - what you call semantics in these slides is more related to the RDF abtract syntax [1] than the RDF semantics [2]. The former is about structural elements of RDF (IRIs, triples...) while the second is about the "things in the world" that the RDF graph is about. > > - In those slides, I see no constraint about preventing triples to talk about themselves (which the CG report explicitly forbids [3]). This allows for something like > > :t1 a :Lie (:t1). > > or, even more tricky to detect > > :t2 a :Truth (:t1). > :t1 a :Lie (:t2). > > This kind of paradoxes may be tricky to model in terms of semantics.... > > pa > > [1] https://www.w3.org/TR/rdf11-concepts/ > [2] https://www.w3.org/TR/rdf11-mt/ > [3] https://www.w3.org/2021/12/rdf-star.html#concepts "Note also that, by definition, an RDF-star triple cannot contain itself" > > On 03/12/2022 00:21, Souripriya Das wrote: >> Attached a revised version of the RDFn slide deck [1] that includes >> • (slide 8) new slide titled "RDFn Semantics: Essentials, in a few words" >> • (slide 9) corrected slide titled "RDFn Semantics: Essentials Beyond RDF" that now states that TI INTERSECT TE need not be an empty set and shows the corrected diagram >> • (slide 14) new slide titled "Enabling Explicit Naming in RDF-star, Serializations, and SPARQL-star" >> Thanks, >> Souri. >> >> [1] https://lists.w3.org/Archives/Public/public-rdf-star-wg/2022Nov/att-0016/RDFn_WG_Slides.pdf > <OpenPGP_0x9D1EDAEEEF98D438.asc>
Received on Tuesday, 13 December 2022 13:26:11 UTC