Re: RIF Negation

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"Adrian Paschke" <adrian.paschke@gmx.de> wrote on 28/04/2009 13:52:56:
> 
> Right, probably it makes sense to have explicit constructs for
> 
> Explicit/Strong/Classical negation                Neg
> Default/Negation-as-failure/Weak/Inflationary     Not

I notice that, in FLD, Michael uses the two names "Neg" and "Naf".

Wouldn't that leave "Not" free for use in PRD, if it is different from the 
other two?

Also, it seems to me that the negation in PRD is not really non-monotonic, 
default or NAF; not in the logical sense. Or is it?

If you have a PRD ruleset that contains the rules:

- If Not(ex:p(ex:a)) then ex:q(ex:a)
- If Not(ex:p(ex:a)) then ex:p(ex:a)

and no fact in your fact base, you will end up with "ex:q(ex:a)" in your 
fact base, if the first rule fires first; even though "ex:p(ex:a)" will 
eventually be added as well (I mean, "ex:q(ex:a)" will not be retracted).

Christian

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