Negation (reprise?)

The excerpt below comes from a Haskell language mailing list.  I have no 
idea (yet) what it precisely means, but seeing the term "type negation", 
and having noticed that Haskell (Hindley-Milner) type inherence problems 
seem to have similarities with more general inference Semantic Web 
problems, I wondered if there was anything here that might inform handling 
of negation in Semantic Web systems...

[[
Yes, I think this is the right way to go. If you look at work by Power, 
Thielecke and Streicher on continuations [*], you will find that they model 
type negation as a self-adjoint functor on a closed premonoidal category, 
and IIRC a closed premonoidal category is equivalent to a thing called a 
closed kappa-category with a computational monad on it. The 
self-adjointness corresponds to the involutivity of negation.
]]

The full message, with some references, is here:
   http://www.haskell.org//pipermail/haskell-cafe/2004-June/006225.html

#g


------------
Graham Klyne
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Received on Friday, 11 June 2004 10:28:58 UTC