Re: Proposal: described vs stated triple terms

On 25 Jul 2024, at 15:18, Thomas Lörtsch <tl@rat.io> wrote:



On 25. Jul 2024, at 15:00, Franconi Enrico <franconi@inf.unibz.it> wrote:

Hi Thomas,

that is exactly how I see it, but Enrico’s responses to Gregory Williams [0] and the RDF/LPG wikipage [1] they refer to seem to suggest a different reading.

I happen to agree 100% with Andy’s email.
I don’t see any contradiction with [0] and [1].

Well, the contradiction is that you talk about a reified statement as if it was asserted in a graph, but you call it optional if it is actually asserted.

I never said that.
I said that a reifier denotes an existing resource in the graph.
A reifier reifies a triple term, and it represents the induced resource by the triple term.
In our example,
:e1 rdf:reifies <<(:a1 :transaction :a2)>>.
:e2 rdf:reifies <<(:a1 :transaction :a2)>>.
:e1, :e2 a :transaction.
there are two transactions, denoted by the two reifiers of the same triple term.
The triple structure of the triple term it reifies does not necessarily appear as a triple in the graph.
But It could, if you want to have it in the graph:
:a1 :transaction :a2.
But this triple in the graph is by no means “identifying” a transaction (in fact, we know that it “relates” to at least two transactions).
So, the graph says that there are two transactions (:e1 and :e2, both between :a1 and :a2), and that the (one) triple :a1 :transaction :a2. is a true fact the graph.

For my terminology, see https://lists.w3.org/Archives/Public/public-rdf-star-wg/2024Jul/0096.html


—e.

[0] https://lists.w3.org/Archives/Public/public-rdf-star-wg/2024Jul/0115.html

[1] https://github.com/w3c/rdf-star-wg/wiki/RDF-star-and-LPGs


On 25. Jul 2024, at 14:32, Andy Seaborne <andy@apache.org> wrote:


On 25/07/2024 11:58, Thomas Lörtsch wrote:
Hi Enrico,

- you didn’t counter my argument that according to your interpretation of the current workline we now do not have a way to describe statements without asserting them


A graph is a set of triples.

A triple T is _asserted in a graph G_ if and only if T is a member of G.


This is the meaning of "asserted" prior to this working group.

As you said last Friday, we drop the "in a graph G" when the graph clear, i..e only one graph under discussion.


The graph

<< :s :p :o >> :q :r .

is

_:B rdf:reifies <<( :s :p :o )>> .
_:B :q :r .

In this graph, the triple :s :p :o is not a member of the set of triples making up the graph.

The triple :s :p :o is not asserted.

The triple via it's triple term is being described (especially when transparent). For me, a "description of a triple" is fine informally - a  description of a thing is not the thing itself.

While understand that <<( )>> is the triple as a 3-tuple, I prefer "triple term" for this usage as an RDF term to make it clear that the triple is not an element of the set of triples making up the graph.

Andy