Re: My opinion of today on the profiles proposal

Hi Niklas,

On Sat, 2024-04-27 at 10:33 +0200, Niklas Lindström wrote:
> Hi Olaf,
>
> [...]
>
> > The reason why I ask is that I am still trying to get my head
> > around:
> >
> > i) what exactly the kind of thing denoted by IRI :r in a triple
> > such as the following is:
> >
> >  ( :r , rdf:reifies , ( :s, :p, :o ) )
>
> It is anything which reifies--as in concretizes--an abstract
> relationship; that relation being a simple logical expression as
> encoded by a triple.

Thanks for this and the following explanations!

I assume that "that relation" in this sentence refers to the "abstract
relationship" mentioned in the first part of the sentence, right?

Regarding this and the following explanations of you, I am somewhat
struggling to understand the distinction between abstract relationships
and the more concrete things that the reifiers are supposed to be.

For instance, given a triple such as

  ( :r, rdf:reifies, (:bob, foaf:knows, :alice) ),

the 'knows' relationship between the resources denoted by the IRIs :bob
and :alice seems relatively concrete to me (ignoring philosophical
discussions of what it means to know someone). In what sense is the
thing denoted by :r more concrete / less abstract than this
relationship?

Thanks,
Olaf


> We're calling these things "reifiers" (thus labelling their *role* as
> subjects of an rdf:reifes triple, not their nature). For examples,
> see
> e.g. [1] and [2].
>
> > ... and ii) what exactly the relationship between the thing denoted
> > by
> > IRI :r and the triple term in that triple is, and also
>
> Suggested definition:
>
>     rdf:reifies a rdf:Property ;
>         rdfs:comment "A property relating anything more concrete or
> specific to one or more abstract relationships."@en ;
>         rdfs:domain rdfs:Resource ;
>         rdfs:range rdf:Triple .
>
> > iii) what the relationship between the statement captured by the
> > following triple and the triple term in the previous triple is (if
> > any)?
> >
> >  ( :r , :p2 , :o2 )
>
> Formally, the same kind of relationship as between any objects that
> are related to by the same subject. I.e. it depends on the nature of
> these relationships when interpreted together.
>
> If the reifer :r is an :Assertion :madeBy and agent :atDate sometime,
> then it's rdf:reifies relation is likely defined, for the :Assertion
> class, to be restricted with cardinality 1, and it represents an
> assertion of that abstract relationship denoted by <<(:s :p :o )>> at
> sometime by said agent. If it is a :Marriage as a kind of situation,
> it is the more concrete circumstance that is, expressed using
> rdf:reifies (the relationship, not the PName), related to likely many
> abstract relationships, that can be seen as "originating from" or
> having been "formed by" that concrete thing. (Concrete here meaning
> the marriage when conceptualized as a concrete, endurant situation,
> with an originating date and location (or related to the ceremony
> reifying those abstract properties), and causing people to become
> spouses, being related to each other, vows to be made, a deity to
> forge (ostensibly lifetime-delimited) bonds of souls, etc.)
>
> Best regards,
> Niklas
>
> [1]: <
> https://lists.w3.org/Archives/Public/public-rdf-star-wg/2024Apr/0158.html

> >
> [2]: <
> https://lists.w3.org/Archives/Public/public-rdf-star-wg/2024Apr/0167.html

> >
>
>
> > Olaf
> >
> >
> > On Fri, 2024-04-26 at 08:05 +0000, Franconi Enrico wrote:
> > > On 26 Apr 2024, at 09:14, Olaf Hartig <olaf.hartig@liu.se> wrote:
> > > > Looking through them now, and also looking again at the
> > > > definition
> > > > of
> > > > the semantics of Profile 1, as given in
> > > >
> > > > https://github.com/w3c/rdf-star-wg/wiki/RDF%E2%80%90star-semantics:-option-3#semantics

> > > >
> > > > it seems to me that the IRI rdf:reifies is in no way different
> > > > from
> > > > any
> > > > other IRI (from the semantics perspective). In other words, the
> > > > meaning
> > > > of the property denoted by this IRI does not seem to be defined
> > > > as
> > > > part
> > > > of this definition. Is this observation correct?
> > >
> > > Yes. If you see at the syntax of the well formed fragment
> > >
> > > graph      ::= ( triple | reifier rdf:reifies tripleTerm )*
> > > triple     ::= subject predicate object
> > > subject    ::= iri | BlankNode
> > > predicate  ::= iri_but_rdf:reifies
> > > object     ::= iri | BlankNode | literal
> > > tripleTerm ::= triple
> > > reifier    ::= iri | BlankNode
> > >
> > > the use of rdf:reifies property is severely restricted in the
> > > syntax,
> > > but its denotation is unrestricted as a property, namely it
> > > behaves
> > > like any other property, e.g., it is many-to-many.
> > > —e.
> > >

Received on Thursday, 2 May 2024 07:07:55 UTC