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Re: owl:sameAs/referential opacity Re: Can RDFstar be defined as only syntactic sugar on top of RDF (Re: weakness of embedded triples)

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Thu, 29 Oct 2020 10:48:20 -0400
To: public-rdf-star@w3.org
Message-ID: <7df1f340-90c8-b49f-778d-537df4d545d7@gmail.com>
It is entirely possible that RDF* could just use RDF(S) semantics for embedded
triples.  If RDF* is simply a shorthand for existing RDF(S) idioms then the
semantics of embedded triples can just fall out of the expansion of the RDF*
shorthands.

The question is whether RDF* can be such a shorthand.  This depends on what
the desired meaning of RDF* constructs is.

RDF semantics is quite flexible with respect to reified statements and there
are several ways to map RDF* embedded triples into reified statements.  Some
ways achieve a form of referential transparency and other achieve a form of
referential opacity.  For example, if an embedded triple is mapped into a
blank-node reified statement then the semantics of embedded triples is quite
transparent.  On the other hand, if an embedded triple is mapped into a
reified statement using a fresh IRI then the semantics of embedded triples is
extremely opaque.  In the middle, an embedded triple could be mapping into a
reified statement using an IRI that is based on the syntax of the embedded
triple.  The semantics of embedded triples then depend on the details of this
mapping.

peter



On 10/29/20 5:07 AM, Pierre-Antoine Champin wrote:
> On 29/10/2020 01:14, thomas lörtsch wrote:
>
>>> On 28. Oct 2020, at 19:31, Pierre-Antoine Champin <pierre-antoine.champin@ercim.eu> wrote:
>>>
>>> (...)
>>>
>>> RDF(S) semantics makes no distinction between "stated triples" and "inferred triples". So unless we change the semantics of RDF (!),
>> !!
> Yes, I wrote that, and you seem to imply that I am contradicting myself,
> but I don't think I am ;-)
>
> RDF(S) semantics knows nothing about "embedded triples", which are
> neither "stated" (I should probably have written "asserted") nor
> "inferred". So it is up to us to decide how this new kind of triples
> should be handled. This is what this whole discussion is about.
>
>
>
Received on Thursday, 29 October 2020 14:48:36 UTC

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