Problem with 'not' (was Re: What do the ontologists want)

   >    [seth russell]
   >    Incidentally, I'm still trying to wrap my pea brain around the idea
   that
   >    there is a problem with 'not' here.   To me {B subClass A.  C subClass
   A.  B
   >    not C.} is a perfectly valid thing to say and nicely implies {B xor C}.
   >    Does it not ?
   >

   [drew mcdermott]
   > ... what does B not C mean?

   It means that if a thing is a B, then it cannot also be a C.

   >Are A, B, and C themselves supposed to be triples
   > or reified triples?

   Nope they are classes - see diagram.

The problem with 'not' is how to negate a triple (or any other
statement).  Expressing (B xor C) doesn't address that problem, does
it?


                                             -- Drew McDermott