Path: ...!news.misty.com!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: WM Newsgroups: sci.math Subject: Re: Incompleteness of Cantor's enumeration of the rational numbers (extra-ordinary) Date: Thu, 9 Jan 2025 23:39:21 +0100 Organization: A noiseless patient Spider Lines: 36 Message-ID: References: <98519289-0542-40ce-886e-b50b401ef8cf@att.net> <8e95dfce-05e7-4d31-b8f0-43bede36dc9b@att.net> <53d93728-3442-4198-be92-5c9abe8a0a72@att.net> <9c18a839-9ab4-4778-84f2-481c77444254@att.net> <8ef20494f573dc131234363177017bf9d6b647ee@i2pn2.org> <66868399-5c4b-4816-9a0c-369aaa824553@att.net> <412770ca-7386-403f-b7c2-61f671d8a667@att.net> <752478087f5326d955ca3ffac4e248d4f50b3ff3@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 09 Jan 2025 23:39:21 +0100 (CET) Injection-Info: dont-email.me; posting-host="f7f0d4de4371fbdb9ecc3d158b8bc074"; logging-data="3764386"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18dXtwyOZ5fYuieY5O437SsHRmXfl7e4fs=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:gx5A9r3atm+eaFu3WTbvOrxsuVc= In-Reply-To: <752478087f5326d955ca3ffac4e248d4f50b3ff3@i2pn2.org> Content-Language: en-US Bytes: 3606 On 09.01.2025 22:22, joes wrote: > Am Thu, 09 Jan 2025 10:30:25 +0100 schrieb WM: >> On 09.01.2025 00:42, joes wrote: >>> Am Wed, 08 Jan 2025 15:35:44 +0100 schrieb WM: >> >>>> A set like ℕ has a fixed number of elements. If ω-1 does not exist, >>>> what is the fixed border of existence? >>> It has an infinite number of elements, and that number happens to be >>> invariant under finite subtraction/addition. >> That is potential infinity, not actual infinity. > No, this is an entirely distinct concept and I don't even use those terms. You don't know what you do. >> That implies the impossibility to extract all >> elements of contents in order to apply them as indices. > No, you just need "extract/apply" infinitely many, which means all natural numbers. Not even one must be missing from the set of indices. >> That destroys Cantor's approach. His sequences do not exist: >> "thus we get the epitome (ω) of all real algebraic numbers [...] and >> with respect to this order we can talk about the nth algebraic number >> where not a single one of this epitome (ω) has been forgotten." [E. >> Zermelo: "Georg Cantor – Gesammelte Abhandlungen mathematischen und >> philosophischen Inhalts", Springer, Berlin (1932) p. 116] > What does this have to do with Aleph_0? It means that no limits are involved but that all not yet used content of endsegments must become indices. Not all endsegments can be infinite. Regards, WM >