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Bob Badour wrote:
[...]
> >>Keith already specified the argument applies to a limit.
> >
> > And this is an incorrect answer because the question was not what the
> > limit of P(A and B) is but what exact value of P(A and B) given P(A) =
> > 0 (or P(B)=0). There is an easy way to derive P(false) from Cox's
> > axioms directly or from the sum/product rules.
>
> The exact value of the sum of 1/2^i for i in [0..infinity] is 2. The
> exact value of the sum of 3 times 10^(-k) for k in [1..infinity] is 1/3.
> The exact value of P(A and B) is 0 give P(A) = 0 or P(B) = 0.
>
> One uses limits to ascertain the truth of all three of the above statements.
I've replied to the limit attempt elsewhere.
>
>
> >>>>P(A) = 1
> >>>>P(A or B) = P(~(~A and ~B))
> >>>>P(A or B) = 1 - P(~A and ~B)
> >>>>P(A or B) = 1 - P(~B|~A)P(~A)
> >>>
> >>>
> >>>Since P(~A) equals zero, the above statement does not make sense.
> >>
> >>But Keith stated "in the limit of". Thus, one could read the first line
> >>of what he wrote as
> >>
> >>lim P(A) as P(A) -> 1
> >
> > 'Limit' is not just a magical word, "hey, presto". One has to show
> > that such limit indeed exists, in what sense it exists, and even then
> > it would be a useless exercise because there is a simple and direct
> > answer (see above).
>
> The only simple and direct answer I see above is the one Keith already
> gave that you refuse to accept no matter how valid it is.
It's not valid in finite models. Received on Mon Jun 12 2006 - 10:10:40 CDT