Re: Logic and Using The Semantic Web Toolbox

>At 12:50 PM 12/4/00 -0600, pat hayes wrote:
>>Tim Berners-Lee *seems* to be saying that negation can be defined 
>>in RDF by reification.
>
>I haven't had the benefit of direct conversation with TimBL on this 
>topic, but based on his design issues "toolbox" paper I *think* he 
>is claiming that negation can be defined using reification *and* 
>introducing some new externally-defined concept;  i.e. that base RDF 
>alone is not sufficient.  Which is what I understand you to be 
>saying.

Ah. OK, I will try again to figure out what is being said. However, I 
rather fail to see what, in this case, the purpose of reification is; 
since if one has a separate ability to introduce an 
externally-defined concept, then what additional functionality does 
the reification provide? I understood that the central role of 
reification in RDF arose from a perception that such importation of 
external concepts was going to be done by the use of reification 
itself: that reification provided some kind of general-purpose 
mechanism for semantic extensibility. If this is not the case, there 
seems to be little reason to have it in the language (?).

Pat Hayes

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Received on Friday, 8 December 2000 17:03:49 UTC