Path: ...!eternal-september.org!feeder3.eternal-september.org!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: joes Newsgroups: sci.math Subject: Re: Incompleteness of Cantor's enumeration of the rational numbers (extra-ordinary) Date: Sun, 19 Jan 2025 15:02:22 -0000 (UTC) Organization: i2pn2 (i2pn.org) Message-ID: <4c768985a7a52263bf11b3bc363d4d55ade3e1d5@i2pn2.org> References: <494bfd3b-3c70-4d8d-9c70-ce917c15fc22@att.net> <72142d82-0d71-460a-a1be-cadadf78c048@att.net> <812e64b1-c85c-48ac-a58c-e8955bc02f8c@att.net> <22b74adc-bf38-4aa4-a44f-622f0a2a5c41@att.net> <77a1069f5c5b8f95927ed9a33ecc6374c9d0a2dd@i2pn2.org> <20e517f6-d709-46fd-83f8-04c6b4fe9f59@tha.de> <4679319ea238a03fb042ae0c4de078c1a310c8a5@i2pn2.org> <320edbb95673eb535f81c16a471811fef7d0f752@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Sun, 19 Jan 2025 15:02:22 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="148837"; mail-complaints-to="usenet@i2pn2.org"; posting-account="nS1KMHaUuWOnF/ukOJzx6Ssd8y16q9UPs1GZ+I3D0CM"; User-Agent: Pan/0.145 (Duplicitous mercenary valetism; d7e168a git.gnome.org/pan2) X-Spam-Checker-Version: SpamAssassin 4.0.0 Bytes: 3348 Lines: 35 Am Sun, 19 Jan 2025 11:59:47 +0100 schrieb WM: > On 19.01.2025 11:42, FromTheRafters wrote: >> WM presented the following explanation : >>> On 18.01.2025 12:03, joes wrote: >>>> Am Fri, 17 Jan 2025 22:56:13 +0100 schrieb WM: >>> >>>>> Correct. If infinity is potential. set theory is wrong. >>>> And that is why set theory doesn't talk about "potential infinity". >>> Nevertheless it uses potential infinity. >> No, it doesn't. > Use all natnumbers individually such that none remains. Fail. Set theory doesn't use "potential infinity". >>> All "bijections" yield the same cardinality because only the >>> potentially infinite parts of the sets are  applied. Quite the opposite. >> No, it is because these bijections show that some infinite sets' sizes >> can be shown to be equal even if no completed count exists. > They appear equal because no completed count exists. The "complete count" is infinite. > All natnumbers in bijections have ℵ₀ not applied successors. A bijection is not meant to be thought about sequentially? > ∀n ∈ ℕ_def: |ℕ \ {1, 2, 3, ..., n}| = ℵo Only potential infinity is > applied. This is not infinity. > In actual infinity all natnumbers would be applied: > ℕ \ {1, 2, 3, ...} = { } > But that is not possible in bijections. It absolutely is. Just give a rule for every natural. -- Am Sat, 20 Jul 2024 12:35:31 +0000 schrieb WM in sci.math: It is not guaranteed that n+1 exists for every n.