Re: Blank Nodes Re: Toward easier RDF: a proposal

On 23/11/2018 10:08 AM, William Waites wrote:
>> The prevailing thought at the time was that there was value in
>> being able to make such "existence" assertions, so that is what
>> we got in the RDF semantics.  But after 20+ years of use, I think
>> it has become clear that this subtle distinction is not actually
>> *needed* in practice, as Skolem IRIs clearly demonstrate.
> FWIW, I have a use-case in synthetic biology that does actually
> use this distinction. If I were to use Skolem IRIs instead, I would
> have to look into the IRI itself to find out if it was a Skolem
> constant or a normal one or else invent a vocabulary for trying
> to talk about statements (oops) and say that they’re meant to
> express existence. That’s all less convenient and less clear than
> checking if the assertion involves existential variables and
> figuring out in an application-specific way what resources exist
> that could be used to satisfy it.
> This is not to say that I couldn’t solve the problem in some other
> very different way, but that there are use-cases where understanding
> blank nodes as meaning existential quantification is actually used
> in practice.

Have you tried to express your use case in SPARQL? While I haven't been 
around for the original RDF semantics discussions, it feels a bit like 
they were attempting to mix data representation with a (simple) query 
and matching language. In retrospect, and with SPARQL now around, this 
was probably an unfortunate decision that caused a lot of unnecessary 


Received on Friday, 23 November 2018 00:19:25 UTC