W3C home > Mailing lists > Public > www-rdf-comments@w3.org > April to June 2002

Re: motivation for bNodes/existentials in RDF; note for parsers

From: Seth Russell <seth@robustai.net>
Date: Fri, 5 Apr 2002 11:10:21 -0800
Message-ID: <012401c1dcd5$8a98d0a0$657ba8c0@c1457248a.sttls1.wa.home.com>
To: "Pat Hayes" <phayes@ai.uwf.edu>
Cc: <www-rdf-comments@w3.org>
From: "Pat Hayes" <phayes@ai.uwf.edu>

> >Source A reads:
> >_:a  rdf:type :ball
> >_:a  :hasColor :blue.
> >_:a  :hasShape :round.
> >_:a  :ownedBy :Seth.
> >
> >Source B reads:
> ><uuid:1615>  rdf:type :ball.
> ><uuid:1615> :hasColor :blue.
> ><uuid:1615> :hasShape :round.
> ><uuid:1615> :ownedBy :Seth.
> >
> >Is this tantamount to the process A reading  "Seth owns some (maybe only
> >one) round blue balls."  and copying to B "Seth owns a round blue ball."?
>
> No, the best way to render that output would be "Seth owns a round
> blue ball called '<uuid:1615>' ".

Yes I get that.  But in the same vein what is your interpretation of the
blank node above?   I was told that existential quantifiers meant:  'at
least one exists such that'.   So (if bnodes are existential quantified
variables) doesn't the blank node above mean the following?

    "At least one round blue ball is owned by Seth."

Now that certainly does not deny that:

   "Seth owns a round ball called <uuid:1615>."

But it doesn't make the same restraints on the world either . does it ?

Seth Russell

   "If you don't want unicorns to exist,
    then don't talk about  them."
             Pat Hayes ~ 2002
Received on Friday, 5 April 2002 14:14:42 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 21 September 2012 14:16:30 GMT