Re: Consolidating triple/edges

Gregg Kellogg
gregg@greggkellogg.net

> On Dec 21, 2023, at 8:01 AM, Franconi Enrico <franconi@inf.unibz.it> wrote:
> 
> 
> 
>> On 20 Dec 2023, at 10:26, Olaf Hartig <olaf.hartig@liu.se> wrote:
>> 
>> That's my reading as well. However, maybe someone with a more intimate
>> understanding of the subtleties* of the notions of a token and an
>> occurrence should look at this question.
>> 
>> *https://plato.stanford.edu/entries/types-tokens/#Occ
>> 
>>> Are these fundamental in the abstract syntax? Or is the token
>>> considered syntactic sugar for something like [] rdfx:occurrenceOf
>>> <<( :s :p :o )>>?
>> 
>> When I read Andy's email, I was assuming the latter, and that's also
>> what my immediate reaction would be, now that you ask this question
>> explicitly.
> 
> 
> I’m trying to write the formal model theoretic semantics of Andy’s proposal.
> I have a problem about having triple terms as the basis for everything.
> Consider the example: 
> 
> :wed-1 rdfx:occurrenceOf <<(:liz :spouse :richard )>> .
> :wed-1 :start 1964; :end 1974 .
> :richard owl:same-as :richard-burton
> ⊨
> :wed-1 rdfx:occurrenceOf <<(:liz :spouse :richard-burton)>> .
> _:b1 rdfx:occurrenceOf <<(:liz :spouse _:b2)>> .
> _:b1 :start 1964 .
> 
> This requires triple terms to have a strong semantic: namely, the identity of triple terms depends on their components.
> 
> For this reason, I tried to formalise a semantics based on triple occurrences.
> You can see it at:
> https://github.com/w3c/rdf-star-wg/wiki/Semantics:-Andy's-proposal

Is it intended that the use of an IRI identifying an occurrence is somehow the same as using the occurrence? Is this use more like that of graph names, where an IRI graph name is correlated with a an occurrence without necessarily denoting the occurrence? For example, given your :liz :spouse :richard example, what would the following mean?

<< :wed-1 | :liz :spouse :richard >> :start 1964 .
:wed-1  :end 1974 .

Another consideration would be what would be expected if requesting a representation of :wed-1? One of the LInked Data principles is that if someone looks up a URI, useful information should be returned, or a SPARQL DESCRIBE? One might expect it would be like retrieving a graph containing just that triple.

I think both of these issues are a bit simpler with Andy’s proposal, where the identifier is a separate resource referring to the triple term, at least I think I have a better intuition on how these things would work.

Gregg.

> cheers
> —e.