Re: Semantics TF discussion

> On 10. Dec 2024, at 16:16, Franconi Enrico <franconi@inf.unibz.it> wrote:
> 
> 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” .

I don’t understand what you are arguing for. In my understanding nothing but a triple term makes sense in the range of rdf:reifies. Or maybe …

    :John60 rdf:reifies :John ;
            :age "60"^^xsd:integer .

… fluents!


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

Really? In my understanding a triple term always, in any position and with any predicate, 
    describes a statement (of a certain type) without stating it. 

And in exactly that way it is used in the range of rdf:reifies. So why give it another type there? I understood or discussion in last Friday’s Semantics TF that all triple terms are of type rdf:Proposition, to dismabiguate them from rdf:Statement. 


.t

> 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.
>> 
>> 
>