> From: Olivier Grisel <[EMAIL PROTECTED]>
> Subject: [Zope3-dev] Re: [DRAFT] local portlets and perspectives
> > (SellerURI, merchandiseURI, BuyerURI, "Sale Transaction")
> Let's rewrite this relation to a prolog equivalent fact:
> transaction(SellerURI, merchandiseURI, BuyerURI, "Sale Transaction").
> There is no primary key in that relation. We could add one such as
> TransactionURI for instance :
> transaction(TransactionURI, SellerURI, merchandiseURI, BuyerURI, "Sale
> In this case we could rewrite this fact without loss of information
> using only binary relations/predicates by projecting it:
> transactionSeller(transactionURI, SellerURI),
> transactionMerchandise(transactionURI, merchandiseURI),
> transactionBuyer(transactionURI, buyerURI),
> transactionType(transactionURI, "Sale Transaction").
> This description is then equivalent and RDF friendly. However it
> requires the introduction of a primary key which was implicit in the
> first description and is much more verbose.
I think the original triadic statement can be encoded with one rdf
triple + context in rdflib:
Graph.add((SellerURI, merchandiseURI, BuyerURI), TransactionURI)
Where TransactionURI is the context. I'm still feeling that these two
models are either equivalent, or there is some property of triadic
relations that I just don't "get" yet. This paper:
http://www.cs.indiana.edu/pub/techreports/TR606.pdf also appears (from
reading the first five pages) to state that reified RDF triples *are*
Peirce relations, which seems to make sense as they are statements about
statements, although I can't claim to really understand the guts of the
I want to reiterate to you guys that I'm not trying to be argumentative
or prove that one thing is better than the other, I take a deep interest
in these subjects and I want to know as much as possible about them.
But unfortunately I think we've strayed off the topic for this list.
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