Re: Semantics TF discussion

On 9 Dec 2024, at 19:29, Andy Seaborne <andy@apache.org> wrote:

Are there any changes to "simple entailment"?
(I don't see any but I'd like confirmation or not)

No changes to simple entailment.

What happens with:

  :s rdf:reifies 123 .

because

  reif1 sss rdf:reifies ooo. ooo rdf:type rdf:Proposition .

means

  123 rdf:type rdf:Proposition

Semantically true, but syntactically only in generalized RDF.
I need to differentiate the entailment patterns for RDF entailment (only sound) with the rule for generalized RDF entailment (sound and complete).

Does there need to be a way of putting it outside RDF Semantics? (if it's there, I'm not seeing it.)

[I+A](t) = TRUE   implies
         <[I+A](t.o), [I+A](rdf:Proposition)> ∈ IEXT([I+A](rdf:type))
         if t.p is rdf:reifies

?? add  "and t.o is a triple term"
to align with the RDF Concepts "SHOULD NOT"

reif1++

   sss rdf:reifies ooo .
   ooo rdf:type rdf:type rdf:TripleTerm .

IMHO, we shouldn’t have such an exception, so to capture the (debatable) case:

:s rdf:reifies “John loves Mary” .

Also, note that not all triple terms are also propositions: this happens only if a triple term appears as an object of rdf:reifies.

cheers
—e.

On 09/12/2024 17:23, Franconi Enrico wrote:
We had an interesting Semantics TF meeting last Friday, and we concluded a couple of things:
1. It would be interesting to consider, instead of the currently
   approved alternative baseline, a simpler more “liberal” approach: a
   new property rdf:reifies is introduced, which is used to express
   reification - namely the relationship between a reifier (sometimes
   called “token") and an abstract triple term. In order to express
   reification, *only* the rdf:reifies (or any sub property of it)
   could be used. Other usages of triple terms (namely without being
   object of a rdf:reifies property or of any of its subproperty) is
   not forbidden (hence the name: “liberal” approach), but they would
   not be having the meaning of a reification.
2. We discussed the possible type of the object of rdf:reifies: it
   could be rdf:Proposition.
This is captured - with many details still to be discussed - in <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22liberal-baseline%22 <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22liberal-baseline%22>>.
—e.