- From: Olaf Hartig <olaf.hartig@liu.se>
- Date: Fri, 5 Jan 2024 14:38:17 +0000
- To: "franconi@inf.unibz.it" <franconi@inf.unibz.it>
- CC: "lindstream@gmail.com" <lindstream@gmail.com>, "public-rdf-star-wg@w3.org" <public-rdf-star-wg@w3.org>
On Fri, 2024-01-05 at 13:55 +0000, Franconi Enrico wrote: > > On 5 Jan 2024, at 14:46, Olaf Hartig <olaf.hartig@liu.se> wrote: > > > > On Fri, 2024-01-05 at 10:58 +0000, Franconi Enrico wrote: > > > On 5 Jan 2024, at 11:42, Niklas Lindström <lindstream@gmail.com> > > > wrote: > > > > Of course, it has implications for how to define these > > > > occurrences > > > > (truth-makers, right [1]?), which we need to come to terms with > > > > together. > > > > For example, I think this makes sense: > > > > > > > > << :wed-1 | :liz :spouse :richard >> . > > > > << :wed-1 | :richard :spouse :liz >> . > > > > :wed-1 a :Marriage ; > > > > :starts 1964 ; > > > > :ends 1974 . > > > > > > > > Would you agree? > > > > > > > > > Yes, it does. > > > > Notice that this diverges quite a bit from the Property Graph > > perspective. PG folks would understand the IRI :wed-1 to be an > > identifier of an edge, and they would see two edges here (one from > > :liz to :richard and another one from :richard to :liz). Then, they > > would get confused because two different edges cannot have the same > > identifier. > > I agree. However, as I observed yesterday, the identity of PG edges > should be encoded in RDF by the property names (emulating a singleton > property), and not by reification. Mmh. From a PG perspective, the predicate of a triple---assuming triples with a non-literal object---is like the label of an edge. In this sense, what you are proposing would appear to PG folks as (mis)using the edge labels as means to identify/distinguish all the edges. > Reification then helps to add properties to the uniquely identified > edges. > This is of course possible with the current semantics. > > > Notice also that a semantics such as this would probably not be > > very > > useful for provenance use cases. I would assume that, in such use > > cases, it makes a difference whether the provenance annotation is > > about > > the triple (:liz, :source, :richard) or about the triple (:richard, > > :source, :liz). > > > I also agree here. Proper provenance use cases do need a more > “syntactical” approach and therefore some form of opacity. > However, the WG decided to go full steam to a fully transparent > (i.e., semantic) approach. When did this happen? In the WG meeting before Christmas (which I didn't attend) or in any of the SemTF meetings? Olaf > That’s why yesterday I proposed that we could study extensions of > this current approach to include optionally some form of opacity > (whatever this may mean…). > > cheers > —e. >
Received on Friday, 5 January 2024 14:38:25 UTC