Path: ...!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: Forgotten to answer? Date: Sun, 26 Jan 2025 10:56:33 +0100 Organization: A noiseless patient Spider Lines: 40 Message-ID: References: <4mVsl7f7IEYIck3oOw7iM3AOjN8@jntp> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 26 Jan 2025 10:56:33 +0100 (CET) Injection-Info: dont-email.me; posting-host="f29b607f7791c09fbf29348f2e168486"; logging-data="3818054"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/qBMtW8Op1QU9DeEQdDyOBAdeT/v9ozqQ=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:GEYG/h+uyFHW+2oC01YAmenhGeg= In-Reply-To: Content-Language: en-US Bytes: 2517 On 26.01.2025 10:08, FromTheRafters wrote: > WM wrote : >> On 25.01.2025 18:03, FromTheRafters wrote: >>> WM pretended : >>>> On 22.01.2025 19:01, Python wrote: >>>> >>>>  > If you have three coins of 2 euros not a single one is >>>> "necessary" to >>>> pay a 3 euros drink >>>> >>>> This failing analogy has been repeated again an again, first by >>>> Rennenkampff, because their authors do not understand the principle: >>>> Cantor's theorem concerns the set of indices or ordinal numbers, not >>>> a set of sets. >>> >>> Then how are these 'Cantor's Theorem' ordinals contructed? >> >> That can be done in an arbitrary way. > > Arbitrarily constructed ordinals? Tell me more! Which of {a, b}, {b, c}, {c, a} are required for the union {a, b, c}? Indexing: 1. {a, b}, 2. {b, c}, 3. {c, a}. The first set is not required because {a, b, c} = {a, b} U {b, c} U {c, a} = {b, c} U {c, a}. The second set is the first required one because {a, b, c} = {b, c} U {c, a} =/= {c, a}. Therefore Cantors's theorem supplies the set of ordinals {2, 3}. By the way, every other choice of indices would yield the same Cantor-set {2, 3}. Regards, WM