- From: Sandro Hawke <sandro@w3.org>
- Date: Fri, 01 Jun 2001 13:47:10 -0500
- 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 course. -- sandro
Received on Friday, 1 June 2001 13:52:22 UTC