W3C home > Mailing lists > Public > www-rdf-logic@w3.org > June 2001

Re: rdf as a base for other languages

From: Sandro Hawke <sandro@w3.org>
Date: Fri, 01 Jun 2001 12:22:51 -0500
Message-Id: <200106011623.MAA10705@tux.w3.org>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: www-rdf-logic@w3.org
In message <20010601115102E.pfps@research.bell-labs.com> you wrote:
> Unfortunately RDF only has triples, so triples end up being used for both
> the ground facts and the more-complex information.  RDF has no way of
> distinguishing between these differing uses of triples, so any triples that
> are used to store the more-complex information are also asserted as facts
> by RDF.  Worse, ....

The "more-complex information" is stored by being described with ground
facts.  What's wrong with that?   Where is the confusion?

The only potential for confusion I see is that some people might want
to jump from having a triple described (with ground facts) to assuming
the described triple is true, but that seems clearly wrong.

Perhaps another possible confusion is around existence: if I describe
to you that x is a blue Honda Civic with license plate 9948JI , does
that mean that such a car exists?    (I think not.)

As a specific example, let's imagine a robot which can jump into the
air.  I can send it knowledge in RDF.  I might say
  :jump17 a :Jump.
  :jump17 :height "21cm".
describing a jump ("jump17") of 21 centimeters.  One could define the
class (":Jump") such that on learning of an instance a receiver should
attempt to perform it.  Alternatively (and I think preferably), one
could define it as abstract, so that you can talk all you want about
jumping, with no one doing anything.   If you want the robot to jump,
you might use a non-RDF channel to say "perform operation :jump17", or
you might define some act-as-soon-as-you-have-knowledge semantics for
a few specific vocabulary terms the robot looks for, perhaps a
":request" term.

    -- sandro

Received on Friday, 1 June 2001 12:23:05 UTC

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