Re: RDF-star "baseline" with IRI opacity

Hi Enrico,

On Fri, Jun 14, 2024 at 2:21 PM Franconi Enrico <franconi@inf.unibz.it> wrote:
>
> Hi,
> after the discussions last week arguing the non-intuitiveness of fully opaque triple terms as literals, and after the comments that opaque tripe terms should have transparent bnodes, I have prepared a new version of the baseline document, where opaque triple terms have opaque IRIs and transparent bnodes:
> https://github.com/w3c/rdf-star-wg/wiki/RDF-star-"baseline-with-IRI-opacity”

Thank you for the update! Does this have any basis in some earlier
proposals too, e.g. from [1]?

I could give a +1 for this as a baseline if it kept subjects as simple
as in RDF 1.1 in the base abstract syntax (i.e. didn't extend them
with tripleTerm). Only this and the previous version "snuck" that in;
your previous "transparent" [2] and "functionally opaque" [3] didn't
touch subjects.  I.e. specifically change back to `subject ::=
NoLiteralAtomicTerm` (your short here for `iri | BlankNode`).

(We're already in agreement in principle that there are no use cases
for it (it being an abstract term, even literal-like; entailment
already happening in "generalized space", etc.). My reasons here are
simply that we should not allow it in N-Triples, so it isn't
accidentally valid and used unknowingly. For that we've also already
agreed that the syntactic sugar uses the forms that this baseline
caters for, specifically to avoid the "seminal mistake".)

> Note that annotations are not anymore functional with opaque triple terms anymore, since it would make little sense with transparent bnodes in opaque triple terms. Still, as I already discussed privately with some of you, even without functionality we should still be able to capture the LPG use cases.

Yes, I think this is simpler. (Not that I couldn't see a stronger
well-formedness solve things; but rather that it could solve things in
a very different way, and that would have been contentious in the WG
to begin to explore further.)

I'm curious if this solution could be amended to make it possible to
entail the meaning (stated relationship) of an "annotation" (triple
token), by entailing other property paths to the triple terms? It
still seems "too late" since that all operates on the interpretation?
Otherwise, since its constituent IRIs are opaque only when referenced
using rdf:annotationOf here; other paths might usefully "see through"
the opacity. For example, just declaring `rdf:annotationOf
rdfs:subPropertyOf rdf:reifies` would be interesting. Such an
interpretation wouldn't block certain integrations through opacity,
and may overcome varying divergent intuitions through vocabulary. (See
[4] for related, detailed examples.)

Cheers,
Niklas

[1]: <https://github.com/w3c/rdf-star-wg/wiki/Semantics:-proposals-by-Peter-Patel%E2%80%90Schneider-for-several-partly-opaque-semantics>
[2]: <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22transparent%22>
[3]: <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22functional-opaque%22>
[4]: <https://github.com/w3c/rdf-star-wg/wiki/Strawman-Proposal:-Triple-Tokens-Entailing-Reified-Statements#compatibility-with-existing-use-cases>


> See you later,
> —e.

Received on Friday, 14 June 2024 13:54:48 UTC