Re: A proposal for basing quotation and annotation upon blank graphs

Thanks Andy. Out of curioty, what would you do of the following N-Quads 
(again, using qnames for convenience only):

     :s :p :o %{g1}

Seems to me that this one has no asserted triple, only a "floating" 
graph term...

What about this one:

     :s :p :o %{g1}.
     :s :p :o %{g2}.
     :a :b %{g1}.
     :c :d %{g2}.

Seems to be that this one would be equivalent (in the /abstract syntax/) to

     :s :p :o %{g1}.
     :a :b %{g1}.
     :c :d %{g1}.

Do you agree? Could that be a problem (non trivial to detect)?

On 12/10/2023 14:00, Andy Seaborne wrote:
> I see using blank nodes as one possible implementation approach. The 
> core idea is graph terms (types) and occurrences (tokens, uses of).
>
> I think we should focus on the whole model with draph terms in the RDF 
> abstract data model; then see how we get there. Just looking at an 
> incremental steps may leave RDF with the blocking legacy for "RDF 1.3".
>
> We can put quoted triples to one side for now and come back to them 
> when the big picture is more settled.
>
>
> Proposal: Syntactic support for graph terms.
>
> We need syntactic support for graph terms. Graph terms will be larger 
> than our one line examples to date - 10s of triples and up. Visually 
> seeing that two graphs are the same graph will be error prone.
>
>   _:a1 rdf:occurenceOf  { :s :p :o }
>   _:a1 rdf:type ....
>   _:a2 rdf:occurenceOf  { :s :p :o }
>   _:a2 rdf:type ....
>
> And we need N-quads support.
>
> Suggestion: Have syntax to define a syntax element:
>
>   USING %{label} FOR { :s :p :o1, :o2 }
>   _:a1 rdf:occurenceOf %{label}
>   _:a1 rdf:type ....
>   _:a2 rdf:occurenceOf %{label}
>   _:a2 rdf:type ....
>
> with
>
>   _:a3 rdf:occurenceOf  { :s :p :o }
>
> is a shorthand for an implicitly generated %{....}. c.f. blank nodes.
>
> "label" is scoped to the document.
>
> There are many ways to have define-use syntax.  The form above keeps 
> these aspects separate and the general style will naturally follow for 
> other syntaxes we need to update.
>
> Unlike current TriG, a label is defined to stand for the graph, not a 
> part of a graph.
>
> Now we can use URIs for tokens and that makes the occurrence and the 
> type accessible over the web.
> https://lists.w3.org/Archives/Public/public-rdf-star-wg/2023Oct/0009.html

>
> It is syntax. It is not in the RDF abstract data model. Graph terms 
> are in the RDF abstract data model.
>
> This might be N-Quads (prefixed names for email only!). No USING needed.
>
>   # 4th slot. Grouping.
>   :s :p :o1 %{g} .
>   :s :p :o2 %{g} .
>   # Use in object slot
>   _:a1 rdf:occurrenceOf %{g} .
>   # Use in subject slot
>   %{g} :property "abc" .
>
> %{} is not a graph name.
>
>    :s :p :o1 %{g} .
>
> co-ops the use of the 4th slot but does not imply it is a graph name.
> Nothing appears in GRAPH ?g {} .
>
> The form "%{ }" has many choices - {} is to suggest "graphs".
>
> JSON-LD use of blank node named graph is not affected.
> Blank nodes could be used for a RDF 1.1 like implementation.
>
> rdf:occurrenceOf was used above because as Pierre-Antoine noted 
> (SemTF) there are different kinds of "occurrence". Syntax that omits 
> the name for the relationship is hiding this and it is something we 
> have to explore.
>
> It may even become a keyword if there is one property but we aren't 
> there yet.
>
>     Andy
>