On 28 May 2001, at 19:17, Ronald J Kimball wrote: > On Tue, May 29, 2001 at 12:51:26AM +0200, Marc Lehmann wrote: > > On Mon, May 28, 2001 at 10:57:17PM +0200, Abigail <abigail@foad.org> wrote: > > > can match infinite strings as well. And since there is an obvious, > > > 1-to-1 mapping between the set of reals between 0 and 1 and the set of > > > strings (including the infite length strings) consisting of digits only, > > > > actually, there isn't on obvious mapping (which is the problem with this > > argument). the set of all strings is countable, the set of reals isn't. > > there are a lot of examples out there that prove that the integers are > > uncountable by extnding them with zeroes, for example. > > I don't follow you. Integers are obviously countable: > > 0, 1, -1, 2, -2, 3, -3, 4, -4, ... > > You say that the set of all strings is countable.... Then, as Abigail > said, the set of reals between 0 and 1 must be countable, because each real > can be represented as a string, specifically a string of digits. Simply put, Abigail is wrong: Regular expressions *cannot* describe "infinite" strings --- what they can describe is "finite but unbounded" strings. Which are *not* enough to get you the reals. /Bernie\ -- Bernie Cosell Fantasy Farm Fibers mailto:bernie@fantasyfarm.com Pearisburg, VA --> Too many people, too few sheep <-- ==== Want to unsubscribe from Fun With Perl? Well, if you insist... ==== Send email to <fwp-request@technofile.org> with message _body_ ==== unsubscribe