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Re: how many RDF* triples?

From: Olaf Hartig <olaf.hartig@liu.se>
Date: Thu, 15 Oct 2020 09:06:04 +0200
To: public-rdf-star@w3.org
Cc: Patrick J Hayes <phayes@ihmc.us>
Message-ID: <2062823.pTQTcvYm3t@porty3>
Hi Pat,

I understand the difference between uncountably infinite sets and countably 
infinite sets, and I see that the set of all possible RDF* triples is 
uncountably infinite. So, in that sense, yes, my comparison to literals was 
imperfect as it was only about infinity without distinguishing between the 
countable and uncountable variant.

The main question is whether the uncountable infinity of all RDF* triples may 
cause problems. I don't see how it may cause problems.

Thanks,
Olaf


On onsdag 14 oktober 2020 kl. 16:27:03 CEST Patrick J Hayes wrote:
> Hi Olaf
> 
> Not quite the same issue with literals. There are countably many literals,
> just as there are countably many possible IRIs and countably many RDF
> graphs. But if Peter is correct, there are uncountably many RDF* triples.
> An uncountable infinity is a lot more than a countable infinity.
> 
> Pat
> 
> > On Oct 14, 2020, at 8:00 AM, Olaf Hartig <olaf.hartig@liu.se> wrote:
> > 
> > Hi Peter,
> > 
> > Right, there is no bound on the nesting depth. However, I don't think that
> > this may cause problems.
> > 
> > By the way, the set of literals is infinite as well, so you have the same
> > issue with RDF triples.
> > 
> > Olaf
> > 
> > On onsdag 14 oktober 2020 kl. 08:46:52 CEST Peter F. Patel-Schneider 
wrote:
> >> I was looking at https://w3c.github.io/rdf-star/ and got to wondering how
> >> many RDF* triples are there?  It appears to me that there are an
> >> uncountable number of RDF* triples because there is no axiom of
> >> foundation
> >> for RDF* triples.
> >> 
> >> So the following is an RDF* triple:
> >> 
> >> _:a :p << _:a :p << _:a :p << _:a :p ... >> >> >>
> >> 
> >> So an RDF* triple could have an infinite number of elements and so there
> >> is
> >> an uncountable number of RDF* triples.
> >> 
> >> Does this cause  any problems for RDF*?  That I am not sure of.
> >> 
> >> 
> >> peter
Received on Thursday, 15 October 2020 07:06:25 UTC

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