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: Thu, 19 Dec 2024 15:38:59 +0100 Organization: A noiseless patient Spider Lines: 42 Message-ID: References: <33512b63716ac263c16b7d64cd1d77578c8aea9d@i2pn2.org> <069069bf23698c157ddfd9b62b9b2f632b484c40@i2pn2.org> <2d3620a6e2a8a57d9db7a33c9d476fe03cac455b@i2pn2.org> <3c08ed64fa6193dc9ab6733b807a5c99a49810aa@i2pn2.org> <357a8740434fb6f1b847130ac3afbd33c850fc37@i2pn2.org> <87351ff85f6c8b1c6c56e8a023f1301298af93e7@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 19 Dec 2024 15:38:59 +0100 (CET) Injection-Info: dont-email.me; posting-host="b073b4606e4aae76152a468e84e37494"; logging-data="3043228"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/pctTcN8GkFZMJSRVph2QoLzKerEnlLJw=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:sX5l6B1x9MFOISmuP5MD1svx0Mw= In-Reply-To: <87351ff85f6c8b1c6c56e8a023f1301298af93e7@i2pn2.org> Content-Language: en-US Bytes: 4147 On 18.12.2024 21:15, joes wrote: > Am Wed, 18 Dec 2024 20:06:19 +0100 schrieb WM: >> On 18.12.2024 13:29, Richard Damon wrote: >>> On 12/17/24 4:57 PM, WM wrote: >> >>>> You claimed that he uses more than I do, namely all natural numbers. >>> Right, you never use ALL the natural numbers, only a finite subset of >>> them. >> Please give the quote from which you obtain a difference between "The >> infinite sequence thus defined has the peculiar property to contain the >> positive rational numbers completely, and each of them only once at a >> determined place." [G. Cantor, letter to R. Lipschitz (19 Nov 1883)] and >> my "the infinite sequence f(n) = [1, n] contains all natural numbers n >> completely, and each of them only once at a determined place." > You deny the limit. > When dealing with Cantor's mappings between infinite sets, it is argued usually that these mappings require a "limit" to be completed or that they cannot be completed. Such arguing has to be rejected flatly. For this reason some of Cantor's statements are quoted below. "If we think the numbers p/q in such an order [...] then every number p/q comes at an absolutely fixed position of a simple infinite sequence" [E. Zermelo: "Georg Cantor – Gesammelte Abhandlungen mathematischen und philosophischen Inhalts", Springer, Berlin (1932) p. 126] "thus we get the epitome (ω) of all real algebraic numbers [...] and with respect to this order we can talk about the th algebraic number where not a single one of this epitome () has been forgotten." [E. Zermelo: "Georg Cantor – Gesammelte Abhandlungen mathematischen und philosophischen Inhalts", Springer, Berlin (1932) p. 116] "such that every element of the set stands at a definite position of this sequence" [E. Zermelo: "Georg Cantor – Gesammelte Abhandlungen mathematischen und philosophischen Inhalts", Springer, Berlin (1932) p. 152] The clarity of these expressions is noteworthy: all and every, completely, at an absolutely fixed position, th number, where not a single one has been forgotten. Regards, WM