Re: Consolidating triple/edges

Well, it depends on the chosen semantics, which has yet to be discussed.
This example should not lead to an inconsistency:

:occurrenceName rdf:occurrenceOf << :bill-clinton :related-to :hillary-rodham >> .
:occurrenceName rdf:occurrenceOf << :42nd-potus :husband :1st-female-NY-senator >> .

I would support the choice with the least constraints, and therefore the choice that does not lead to an inconsistency.
Moreover, under the semantics leading to inconsistency, you would have a way to add inequality to RDF, which probably we don’t want:

:a rdf:occurrenceOf << :fake1 :fake1 :fake1 >> .
:b rdf:occurrenceOf << :fake2 :fake2 :fake2 >> .
entails < :a owl:differentFrom :b >.

cheers
—e.

On 15 Dec 2023, at 01:28, Gregg Kellogg <gregg@greggkellogg.com> wrote:

I’d say it can’t be a syntactic constraint but may be a semantic inconsistency due to open-world assumption.

Gregg Kellogg
Sent from my iPhone

On Dec 14, 2023, at 3:41 PM, Olaf Hartig <olaf.hartig@liu.se> wrote:

Andy,

Dec 12, 2023 21:59:24 Andy Seaborne <andy@apache.org>:
[...]

## Turtle

Add to Turtle a new statement (grammar rule 2):

   << occurrenceName | :s :p :o >> .

This names an occurrence of the triple s p o.

The triple is not asserted, keeping "assertion" and "occurrence" as orthogonal concepts even if they might commonly be used together.

occurrenceName is a URI or blank node, including [] (the ANON terminal rule 47 in Turtle - no triples inside the []).

It is better to have the name first to allow for split lines and modified annotation syntax below.


## N-Triples

In N-Triples, reflecting the RDF abstract data model, there is a property to relate occurrence to a triple term.

   :occurrenceName rdf:occurrenceOf << :s :p :o >> .

What should happen if someone writes the following two lines?

 :occurrenceName rdf:occurrenceOf << :s1 :p1 :o1 >> .
 :occurrenceName rdf:occurrenceOf << :s2 :p2 :o2 >> .

Should the abstract syntax contain a constraint by which such a multi-use of :occurrenceName is defined to be invalid? Or should this be treated as an inconsistency under whatever entailment regime that is concerned with such rdf:occurrenceOf statements?

Thanks,
Olaf


There are triples terms in the data model
(RDF-Concepts - section 3.1 : editors draft [2]).

Renaming "quoted triple" as "triple term" would be better because it has less implication of the usage.

The NT syntax would be available in Turtle in the same way that rdf:first is available in Turtle - and with the same expectation that it would rarely be used.


## RDF Graph Merge

Graph merge happens as before - blank nodes need to be kept apart.


## Annotation

This gives the modified annotation syntax as per Thomas's email [1]:

   :liz :spouse :dick { id:1 | :start 1964; :end 1974 |} .
   :liz :spouse :dick { id:2 | :start 1975; :end 1976 |} .

Slight syntax tweak: For SPARQL, reusing { has to be careful because { is a group start.

:liz :spouse :dick {| id:1 | :start 1964; :end 1974 |} .
:liz :spouse :dick {| id:2 | :start 1975; :end 1976 |} .

which would map to
   id:1 rdfx:occurrenceOf << :liz :spouse :dick >> ;
        :start 1964; :end 1974 .
   id:2 rdfx:occurrenceOf << :liz :spouse :dick >> ;
        :start 1975; :end 1976 .

and asserting:

   :liz :spouse :dick .


## Named occurrences in term slots

<< occurrenceName | :s :p :o >> could also be used in a subject or object slot with the occurenceName being the RDF term for subject or object (c.f. RDF collections and predicate object lists) for use with unasserted triples:

<< [] | :s :p :o >>
      :start 1964 ;
      :end 1974 .

    Andy

[1]
https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.w3.org%2FArchives%2FPublic%2Fpublic-rdf-star-wg%2F2023Dec%2F0024.html&data=05%7C02%7Cfranconi%40inf.unibz.it%7Cab7c3c7f4bbb43ecbc6308dbfd04e0de%7C9251326703e3401a80d4c58ed6674e3b%7C0%7C0%7C638381969624677346%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=gSagZ08dopprR5tnLYp7lkBfLtmnVnKWBSgONVsVP4s%3D&reserved=0


[2] https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fw3c.github.io%2Frdf-concepts%2Fspec%2F%23section-triples&data=05%7C02%7Cfranconi%40inf.unibz.it%7Cab7c3c7f4bbb43ecbc6308dbfd04e0de%7C9251326703e3401a80d4c58ed6674e3b%7C0%7C0%7C638381969624833608%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=q%2F4Fu7VyvAyfcgtFFgRtTEA6XVgQPAu0H8lF6ZgTHZE%3D&reserved=0

    (as of 2023-12-10)