Path: ...!weretis.net!feeder9.news.weretis.net!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: joes Newsgroups: sci.math Subject: Re: Incompleteness of Cantor's enumeration of the rational numbers Date: Tue, 19 Nov 2024 12:05:51 -0000 (UTC) Organization: i2pn2 (i2pn.org) Message-ID: <50333708eb8aac45243baf9fb69479379b783b63@i2pn2.org> References: <65febd06-662b-4fa4-9aa8-f7353a79a110@att.net> <157a949d-6c19-4693-8cee-9e067268ae45@att.net> <8165b44b-1ba5-429d-8317-0b043b214b53@att.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Tue, 19 Nov 2024 12:05:51 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="3184812"; 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: 3186 Lines: 32 Am Mon, 18 Nov 2024 23:16:22 +0100 schrieb WM: > On 18.11.2024 22:58, FromTheRafters wrote: >> on 11/18/2024, WM supposed : >>> On 18.11.2024 18:15, FromTheRafters wrote: >>>> WM brought next idea : >>> >>>>>> |ℕ| - |ℕ| = 0 because if you subtract one element from ℕ then you >>>>>> have no longer ℕ and therefore no longer |ℕ| describing it. |N\{0}| = |N| = Aleph_0 >>> If you remove one element from ℕ, then you have still ℵo but no longer >>> all elements of ℕ. >> But you do have now a proper subset of the naturals the same size as >> before. > It has one element less, hence the "size" ℵo is a very unsharp measure. You can still say it is a subset, like Cantor did with "reality". >>> If |ℕ| describes the number of elements, then it has changed to |ℕ| - >>> 1. >> Minus one is not defined. > Subtracting an element is defined. |ℕ| - 1 is defined as the number of > elements minus 1. And |N\{2}| = Aleph_0. >>> If you don't like |ℕ| then call this number the number of natural >>> numbers. >> Why would I do that when it is the *SIZE* of the smallest infinite set. > The set of prime numbers is smaller. There are infinitely many of them. -- 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.