Re: Decision from the Semantics TF: liberal baseline

My 2 ¢ about 
https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22liberal-baseline%22#rdf-semantics

- for the sake of homogeneity, I would keep only reif1 and reif2 in RDF 
Semantics,
   and push reif3 in RDFS Sedmantics (which would simply mean to add the 
axiomatic triple rdf:reifies rdfs:range rdf:Proposition . This is for 
the sake of regularity. I don't think that RDF semantics has any 
"range-like" entailment for the moment.

- regarding the distinction between "if S contains" and "if the triple 
structure appears in S", I think I would prefer to keep "if S contains" 
for all entailment patterns. What happens in a triple term stays in a 
triple term. People may want to talk about non-sensical triples, and any 
inference transpiring from triple terms may make this inconsistent.
   pa


On 07/01/2025 16:16, Franconi Enrico wrote:
> On 7 Jan 2025, at 15:44, Doerthe Arndt <doerthe.arndt@tu-dresden.de> 
> wrote:
>
>> I noticed that you used the wording "if the triple structure appears 
>> in S“ for the conditions.
>> From your e-mail I assume that „triple structure appears in“ is not 
>> the same as the original „S contains“ we have for the other patterns 
>> and that you changed the wording to deal with nesting.
>
> Correct.
>
>> I think we need to be very clear what this means and that we include 
>> nesting here.
>
> Sure.
>
>> Here we also come to the question you raised in the mail. So, from 
>> your point of view you would always want to have this „triple 
>> structure appears in“ notion? Or would you want to have some 
>> distinction between „triple structure appears in“ vs „triple is 
>> element of S“? Where else would we need the first notion?
>
> I  want to hear comments from other people about how to define  these 
> metamodelling properties (about which, as I have been abundantly made 
> clear, I couldn’t care less 😀).
> For elegance and symmetry, I am tempted to have the „triple structure 
> appears in“ notion.
> However, please note the following example:
>
>     :john :believes _:r1 .
>     _:r1 rdf:reifies <<(:paul rdf:type :canadian)>> .
>     /currently/ does NOT rdfs entail
>     :canadian rdf:type rdfs:class .
>     :paul rdf:type rdfs:resource .
>
>
> That is, metamodelling entailments within /nested/ triple terms do not 
> currently hold.
> So, either we change *_all_* the RDF/RDFS entailments to hold also in 
> /nested/ triple terms (rather impactful), or we allow for entailments 
> only at top level.
> The above example suggests that we should allow for entailments only 
> at top level (and so I have to revert to the previous version of the 
> semantics).
> What do you (and anybody else) think?
>
>> According to the semantics as you have it at the moment, we would 
>> need „triple structure appears in“ for both current RDF entailment 
>> patterns, right?
>
> Yes.
>
> —e.
>
>
>>> Am 02.01.2025 um 17:29 schrieb Franconi Enrico <franconi@inf.unibz.it>:
>>>
>>> At the last Semantics TF we discussed about the RDF semantics of the 
>>> liberal baseline.
>>> In the current version of the document:
>>> https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22liberal-baseline%22#rdf-semantics
>>> the two discussed restrictions of RDF semantics are formalised:
>>>
>>>   * triple terms, appearing in triples or in triple terms, are of
>>>     type /rdf:proposition/;
>>>   * objects of the property /rdf:reifies/, appearing in triples or
>>>     in triple terms, are of type /rdf:proposition/.
>>>
>>> We may decide to have both restrictions, any of them, or none.
>>> Let’s open the general discussion :-)
>>> —e.
>>>
>>>> On 13 Dec 2024, at 18:20, Franconi Enrico <franconi@inf.unibz.it> 
>>>> wrote:
>>>>
>>>> Today the Semantics TF met, and we agree to submit to the working 
>>>> group a proposal for a /liberal baseline./
>>>> It is summarised in 
>>>> <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-%22liberal-baseline%22>, 
>>>> to be discussed (and voted?) at the first focussed meeting in 2025.
>>>> Basically, there will be a no syntactic restriction in using both 
>>>> /rdf:reifies/ and /triple terms/.
>>>> Reification is sanctioned only if it makes use of the property 
>>>> /rdf:reifies/ or any of its subproperties; the subject of 
>>>> /rdf:reifies/ is called a /reifier/.
>>>> /Triple terms/ would be always of type /rdf:Proposition/, and the 
>>>> range of /rdf:reifies/ would be /rdf:Proposition/.
>
>