Re: Blank nodes must DIE! [ was Re: Blank nodes semantics - existential variables?]

On Fri, 3 Jul 2020 at 00:00, Patrick J Hayes <phayes@ihmc.us> wrote:

> Dieter, greetings.  We are of course aware of this issue.  It is mentioned
> in the RDF 1.1 overview document in the W3C recommendations,
> https://www.w3.org/TR/rdf11-concepts/#section-skolemization. But it is
> not hard to achieve in practice, eg use a pseudorandom number generator
> seeded with a string of the current date/time and the what threewords
> location of the generating host, then append the resulting string to a URI  whose
> path component starts with /.well-known/genid/.
>

UUID generation looks to be well specified too,
https://tools.ietf.org/html/rfc4122

...though we will too often end up with differing ids for nodes
representing the same real world thing.

The idea of taking knowledge of functional and inverse-functional
properties into account is interesting (perhaps in some post-parsing
canonicalization step aka "smushing"...).

Dan



> Pat
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>
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> On Jul 1, 2020, at 8:09 AM, Dieter Fensel <dieter.fensel@sti2.at> wrote:
>
> Actually skolemization is quite an old concept of computational logic (I
> guess older than most of us) to deal with existential variables.
> Unfortunately it comes along with the typical closed world assumptions of
> logic assuming that you know all terms and can safely generate a unique new
> term. In the open and dynamic environment of the web this may cause
> problems. What happens if two people use the same skolemization generator
> and their stuff gets merged?
>
> On 01.07.2020 13:02, David Booth wrote:
>
> Yes, excellent work!  I think skolemizing may be useful as an underlying
> mechanism, largely hidden from users.
>
>
> --
> Dieter Fensel
> Chair STI Innsbruck
> University of Innsbruck, Austria
> www.sti-innsbruck.at/
> tel +43-664 3964684
>
>
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>