Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Moebius Newsgroups: sci.logic,sci.math Subject: Re: Replacement of Cardinality Date: Fri, 16 Aug 2024 09:22:55 +0200 Organization: A noiseless patient Spider Lines: 22 Message-ID: References: <75e2ce0e-7df8-4266-968b-9c58e4140b03@att.net> <35d8c0a1-dab3-4c15-8f24-068e8200cb07@att.net> <4412ba58-855f-401d-9fd0-879d5cb50062@att.net> <219eed30-9918-4759-9b7e-826088fc91c9@att.net> <0aae40c7-1092-4b12-99dc-290aa5a94021@att.net> <80662980-e93e-4af4-9489-f17fad3097d1@att.net> Reply-To: invalid@example.invalid MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 16 Aug 2024 09:22:55 +0200 (CEST) Injection-Info: dont-email.me; posting-host="8de5541c6b599521b97afbd172dfb739"; logging-data="1437586"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+4o1r9uGopWrOjADvL2MIt" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:OdRPPngu5rbWltQ5GY7VpU7YKpw= Content-Language: de-DE In-Reply-To: Bytes: 2439 Am 16.08.2024 um 08:48 schrieb Chris M. Thomasson: > On 8/15/2024 10:57 PM, Moebius wrote: >> Am 16.08.2024 um 07:50 schrieb Moebius: >> >>> Of course, _if_ we already have introduced the real numbers (i.e. IR) >>> we may define >>> >>>        √2 = the real number x such that x^2 = 2 ,    (*) >>> >>> _after_ we have shown that there is exactly one x e IR such that >>> x^2 = 2. >>> >>> From (*) we get immediately: (√2)^2 = 2 >> >> Now we may assume that there are natural numbers n,m such that √2 = n/m. >> >> (...) > > The infinite convergents of continuous fractions can describe sqrt(2) up > to any desired precision? Sure.