Path: ...!eternal-september.org!feeder2.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 Date: Wed, 20 Nov 2024 13:01:29 +0100 Organization: A noiseless patient Spider Lines: 20 Message-ID: References: <8165b44b-1ba5-429d-8317-0b043b214b53@att.net> <883377b7ebbd9d5d528db048daf9f682e3854ae8@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Wed, 20 Nov 2024 13:01:30 +0100 (CET) Injection-Info: dont-email.me; posting-host="10af3bc7caee4ceaa4972e93614969c0"; logging-data="71150"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18f8IDnJoDb3s+KcDDHFdAuWb34M6C4DBU=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:fiKXQlxcYXv6kGr1n/IKCXjgDVg= In-Reply-To: Content-Language: en-US Bytes: 2594 On 19.11.2024 17:40, FromTheRafters wrote: > WM was thinking very hard : >> Only finite sets are countable. > > Wrong, it is countable if there is a bijection. They are erroneously called countable, but they are not countable. >> But all "countably" infinite sets have the same size, which according >> to the different numbers of elements is a very unsharp measure. > > That you don't like cardinal arithmetic, doesn't make cardinal > arithmetic wrong. It does not make it wrong, but it unmasks it at imprecise. That's why I don't like it. We can do better. Regards, WM