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Re: rdf as a base for other languages

From: Sandro Hawke <sandro@w3.org>
Date: Fri, 01 Jun 2001 13:47:10 -0500
Message-Id: <200106011747.NAA21720@tux.w3.org>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, www-rdf-logic@w3.org
In message <20010601130755B.pfps@research.bell-labs.com> you wrote:

>For example, suppose that you wanted to represent propositional formulae
>within RDF.  You might do something like:
><rdf:type x OR>
><component x y>
><component x z>
><rdf:type y rdf:Statement>
><rdf:subject y John>
><rdf:predicate y loves>
><rdf:object y Mary>
><rdf:type z rdf:Statement>
><rdf:subject z John>
><rdf:predicate z loves>
><rdf:object z Susan>
><loves Bill Susan>
><rdf:type Bill Person>
><rdf:type John Person>
><rdf:type Susan Person>
><rdf:type Mary Person>
>You understand this collection of RDF triples to mean that Bill loves
>Susan and John loves either Mary or Susan, and that they are all people.

Well, not really.  I had to think about which kind of OR you meant.
Did you you mean to just declare a relation (r=y OR z) or did you mean
to assert something (true=y OR z)?  I (with help from Eric
Prud'hommeaux looking over my shoulder) made a closed-world
assumption, noting the absense of <result x r>, and decided you meant
the later version.

The two kinds of OR are exactly like my two kinds of robot actions:
does it jump when I tell it about a jump, or does it wait until I
specifically ask it to perform the jump?

The point is that some RDF vocabular terms need to be defined as
"operational" or "performative" for particular agents.  Your OR was a
performative OR, where the operation was to add a disjunction to the
knowledge base obtained by reading the text.  That operation could
only be performed by an agent which understands disjunction, of

    -- sandro
Received on Friday, 1 June 2001 13:52:22 UTC

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