Re: Proposal for RDF-star Minimal Baseline - Agenda item for this week's plenary

Dear Enrico, all,

As I do not want to create a big discussion here (so please, hold your horses for now :) ), but I had a few thoughts on the baseline semantics as it is in  https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22minimal-baseline%22. (The mail can also be answered after our meeting, sorry for it being so late. The thoughts came because I prepared for our discussion)

I think we should discuss a few points in the semantic task force, but  given our latest history, I would like to pre-filter the issues and especially not re-discuss thinks we already agreed on. So, if I missed discussions where you came to agreements about the below, it might be enough to just answer with a link.

- injectivity of RE: in my opinion there is no real reason to make the function injective and I think it could cause harm in the sense that such restriction can lead to inconsistencies when we extend the logic.  I guess that was discussed in a task force meeting I was not present? Maybe I can read it up somewhere?

- semantics of triple terms: in your abstract syntax, the :a :b :c in your triple :s :p << :a :b :c>> is a triple and a triple term at the same time, in my opinion, it is therefore not clear that the [I+A](t.o) in the interpretation  [I+A](t) of the overall triple refers to the term interpretation and not the triple interpretation. I think that should be stated more clearly. We should emphasize the difference between a triple and a triple term.

- well-formed semantics: I don’t think that it really works make the restriction on rdf:reifies as you currently do it in the well-formed syntax. As I have RDFS, I could declare:

doerthe:reifies rdfs:subPropertyOf  rdf:reifies.
rdf:reifies rdfs:subPropertyOf  doerthe:reifies.


Now, I have a predicate doerthe:reifies which behaves like rdf:reifies and this makes the restriction not really strong (thinking about it, it is interesting, that I(rdf:reifies) and I(doerthe:reifies) can still differ). I think we could drop the restriction, but I also did  not fully understand the reason for having it in the first place, maybe you can explain?
We can still keep that triple terms may only be in the object position of rdf:reifies, even though, I dislike that (I think I already explained why, mainly because I want to be able to express all logical consequences, but that is a separate topic).


- we should start to think about all the RDF meta modeling stuff, because I am curious whether that could lead to problems especially in combination with the well-formed semantics


Kind regards,
Dörthe

Am 16.07.2024 um 19:20 schrieb Adrian Gschwend <adrian.gschwend@zazuko.com>:

Dear group,

During the recent Semantics Task Force call, there was an informal agreement to propose a resolution for the main group [1]. The proposed resolution is to implement the minimal baseline for RDF-star as outlined in the following document: RDF-star "minimal baseline" [2].

The chairs (Ora and I) have discussed this matter and we support bringing this topic to the main group for a formal resolution.

We would like to add this proposal to the agenda for this week's meeting. Additionally, we request that a representative from the Semantics TF present this proposal to the group. Ideally, this could be done via email prior to the meeting to ensure everyone has the opportunity to review and prepare for the discussion.

regards

Ora & Adrian

[1]: https://www.w3.org/2024/07/12-rdf-star-minutes.html

[2]: https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22minimal-baseline%22


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Adrian Gschwend
CEO Zazuko GmbH, Biel, Switzerland

Phone +41 32 510 60 31
Email adrian.gschwend@zazuko.com