Re: ?? Functional Dependency Question ??

On Oct 23, 2:23 am, David BL <davi..._at_iinet.net.au> wrote:
> On Oct 22, 7:20 pm, JOG <j..._at_cs.nott.ac.uk> wrote:
>
>
>
> > Ax [ inRoom(x) ^ isHippo(x) ^ Wearing(x, pink panties) ] = false
>
> Is this actually the case?  There doesn't appear to be any defined set
> over which the universal quantification is defined, so I think the
> left hand side is meaningless not false.
>
> I think a meaningful universal quantification must be able to be
> written in the form
>
>     Ax [ P(x) -> Q(x) ]
>
> where { x | P(x) } is a well defined set.
>
> We can write
>
>     Ax [ inRoom(x) ^ isHippo(x) ^ Wearing(x, pink panties) ]
>
> as
>
>     Ax [ true ->  inRoom(x) ^ isHippo(x) ^ Wearing(x, pink panties) ]
>
> So it seems that we must define P(x) = true, but then { x | P(x) } is
> the set of all things which is meaningless.
Received on Mon Oct 27 2008 - 00:48:50 CET