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Re: SUO: RE: First piece of 4D ontology




> > ;
> > ; #2:
> > ;
> > ; for all X, if there exists a Y and Y is a member of X, then X is a
> > ; member of collection.
> > ;
> > ; i.e. any thing that has a member is a collection.
> > ;
> > (forall ?x
> >    (=> (exists ?y
> >           (?x ?y)
> >        )
> >        (collection ?x)
> >    )
> > )
> > ; Note: This (?x ?y) is not valid SUO-KIF today, but I understand it
> > ;       will be in the near future.
>
>You could express (?x ?y) as (instance-of ?y ?x), which is syntactically
>well-formed SUO-KIF.  However, it is also not a first-order sentence.

In the new version of KIF it will be both legal and have a 
first-order semantics. So to the extent that this is a sentence in a 
first-order logic, it is a first-order sentence.

Pat Hayes

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