Path: ...!eternal-september.org!feeder3.eternal-september.org!news.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: Sun, 29 Dec 2024 11:34:08 +0100 Organization: A noiseless patient Spider Lines: 27 Message-ID: References: <4051acc5-d00a-40d2-8ef7-cf2b91ae75b6@att.net> <8d69d6cd-76bc-4dc1-894e-709d044e68a1@att.net> <7356267c-491b-45c2-b86a-d40c45dfa40c@att.net> <4bf8a77e-4b2a-471f-9075-0b063098153f@att.net> <31180d7e-1c2b-4e2b-b8d6-e3e62f05da43@att.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 29 Dec 2024 11:34:09 +0100 (CET) Injection-Info: dont-email.me; posting-host="0a8d1c301754f45f71cb6cb758160409"; logging-data="955690"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19dETnEW+XLPsQUNtQJGXSWwnMKQmsOK98=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:SjYKtajf2CKqlLMARrcDVL3mglY= Content-Language: en-US In-Reply-To: Bytes: 2836 On 28.12.2024 18:31, Jim Burns wrote: > On 12/28/2024 9:03 AM, WM wrote: >> [0, ω-1] = [0,ω⦆ = ℕ =/= [0, ω] > > Yes, > ⟦0,ω⦆  =  ℕ  ≠  ⟦0,ω⟧ > > However, > ⎛ Assume k < ω > ⎜ #⟦0,k⦆ ≠ #(⟦0,k⦆∪⦃k⦄) > ⎜ #⟦0,k+1⦆ ≠ #(⟦0,k+1⦆∪⦃k+1⦄) > ⎝ k+1 < ω That holds for almost all natural numbers k. It cannot hold for an actually infinite system without disappearing Bob. For example, all endsegments obey the sequence defined by ∀k ∈ ℕ : E(k+1) = E(k) \ {k+1}. If all natnumbers exist, then all will leave the terms of the sequence, but cannot other than in single steps including the dark endsegments E(ω-3) = {ω-2, ω-1}, E(ω-2) = {ω-1}, E(ω-1) = { }. ∀k ∈ ℕ : E(k+1) = E(k) \ {k+1} does not allow another alternative. Regards, WM