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Re: [jena-dev] Re: Use cases for Reification in RDF Triplestores

From: Seth Russell <seth@robustai.net>
Date: Thu, 09 Jan 2003 18:36:37 -0800
Message-ID: <3E1E31B5.2080901@robustai.net>
To: pat hayes <phayes@ai.uwf.edu>
CC: Bob MacGregor <macgregor@ISI.EDU>, www-rdf-interest@w3.org

pat hayes wrote:

> Many people have suggested using reification to simulate expression 
> nesting in recursive syntax, but  this kind of usage for reification 
> was a mistake from the start. A complex expression like
> (A and B ) or (C and D)
> does not *mention* its disjunctive components, so to use reification 
> to encode complex propositional expressions in a triple store was a 
> semantic disaster waiting to happen. (This point has been labored to 
> death in many email forums.)  If the WG decision on reification has 
> rescued you from doing that, be thankful. 

What is the big difference re use\mention between a KIF expression like 
(or (depicts some:image Jill) (depicts some:image John)) and a 
corresponding N3 statement  [:or [some:image :depicts :Jill] [some:image 
:depicts :John]] ?   It seems to me that in both languages the range of 
"or" is the *truth* of the nested component, not the nested component 
itself.  What is the big difference that seems to have attached itself 
to RDF triple type languages that did not attach itself to KIF ?

re diagram:  http://robustai.net/mentography/or_not.gif

Seth Russell
Received on Thursday, 9 January 2003 21:37:15 UTC

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