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Re: Troublesome relations

From: Thomas B. Passin <tpassin@comcast.net>
Date: Tue, 19 Oct 2004 11:05:16 -0400
Message-ID: <41752D2C.9050607@comcast.net>
To: www-rdf-interest@w3.org

Peter F. Patel-Schneider wrote:

> However, even then I don't see any impediment to representing this trinary
> relationship as
> 
> 	_:a rdf:type ex:marriage .
> 	_:a ex:groom ex:John .
> 	_:a ex:bride ex:Sally .
> 	_:a ex:dog ex:Fido .
> 
> or
> 
> 	_:a rdf:type ex:marriage .
> 	_:a _1 ex:John .
> 	_:a _2 ex:Sally .
> 	_:a _3 ex:Fido .
> 

Right, Peter, and (I am agreeing that) this is just how n-ary relations 
have to be represented in RDF.  From my point of view,

1) All the statements get glued together by means of the _:a bnode.
2) The _:a node is acting more or less like an n-ary predicate - or a 
conceptual relation in Conceptual Graphs - but
3) It is actually not a predicate from the RDF point of view - in RDF 
only those things in the middle of triples are predicates, as best I 
understand it.

Well, my main interest here is just in trying to clarify (triggered by 
Danny's original post) that there are really higher arity things of 
importance in RDF, and it's good to keep that in mind, even if they can 
be disguised by the formalism.

Cheers,

Tom P


-- 
Thomas B. Passin
Explorer's Guide to the Semantic Web (Manning Books)
http://www.manning.com/catalog/view.php?book=passin
Received on Tuesday, 19 October 2004 15:03:53 GMT

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