Re: Cardinality of Set of Computable Numbers?

From: George Greene (greeneg_at_greeneg-cs.cs.unc.edu)
Date: 12/26/03 

Date: 26 Dec 2003 15:36:06 -0500

magidin@math.berkeley.edu (Arturo Magidin) writes:
 : I don't really see how to do this. Do you know that every computable
 : number has an infinite number of digits? If not, how do you know that
 : f^{-1}(j) (i.e., the j-th computable number) has at least j digits, so
 : that you can define a new number whose j-th digit is different from
 : the j-th digit of f^{-1}(j)?

It's a lot worse than that; he didn't originally know what he meant by
"number"; by itself, "number" is simply too vague.
If he meant "real number" then he really was obligated to SAY that.

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