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Re: Cantor's diagonalization argument

Subject: Re: Cantor's diagonalization argument
From: "Mark-T"
Date: 31 Oct 2006 11:38:16 -0800
Newsgroups: sci.math, sci.logic
Virgil wrote:
> > > It is talking about existence, and it successfully proves that
> > > existence (of a number absent from a list). In fact the prescription
> > > can be used to show that there are uncountably many numbers
> > > absent. It doesn't need to construct any particular number,
> > > just prove that at least one exists.
> > >
> > > There are many cases in mathematics where things are
> > > known to exist but there may not be a procedure to find
> > > them in finite time.
> >
> > Examples?  (besides diagonalization)
>
> The decimal representations of the square roots of primes.

OK, but that's a much simpler case, which doesn't raise the
thorny issues of the diagonalization argument...

Mark


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