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

On 29/10/2020 15:48, Peter F. Patel-Schneider wrote:

> 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.

I agree. Actually, I'm beginning to think that even the
"bnode-supporting referential opacity" that we aimed to achieve with the
extended semantics, could actually be achieved inside RDF standard
semantics. I'll share that when my ideas are clearer.

>
> 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.
>>
>>
>>