Path: ...!eternal-september.org!feeder3.eternal-september.org!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: joes Newsgroups: sci.math Subject: Re: The set of necessary FISONs Date: Sun, 2 Feb 2025 04:55:15 -0000 (UTC) Organization: i2pn2 (i2pn.org) Message-ID: References: <4d349964-211f-42f1-936f-81c22ae54cb5@att.net> <6e0c8ab2-402a-43a5-a348-0c727eae6a2e@att.net> <87e2e677c7802c9c17df6063f340cb5857d5700b@i2pn2.org> <680d4249c9bf1504231a53732ac5096184261495@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Sun, 2 Feb 2025 04:55:15 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="2280353"; 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: 3032 Lines: 27 Am Sat, 01 Feb 2025 19:23:29 +0100 schrieb WM: > On 01.02.2025 15:07, joes wrote: >> Am Sat, 01 Feb 2025 13:46:50 +0100 schrieb WM: >>> On 31.01.2025 18:51, joes wrote: >>>> Am Fri, 31 Jan 2025 13:28:35 +0100 schrieb WM: >>> >>>>> then all can be discarded, >>>> No, only finitely consecutive ones. >>> Induction concerns all natural numbers n as well as all A(n). >> ω, corresponding to „all”, is not natural. > ω describes the order type but is not the set ℕ but greater than all > natnumbers. Induction proves a sentence for every number, not for the set. You cannot extend a sentence about numbers to sets. >>>>> Removing all leaves nothing, in particular no sufficient set for >>>>> U(F(n)) = ℕ. >>>> It is obvious that N is not empty. >>> But the set claimed to have the union ℕ gets empty without changing >>> its union. >> Wrong. Finite sets of FISONs do not result in N. > Induction covers all natural numbers. Otherwise it would not be > sufficient in the Peano axioms. It covers the elements of N, not the set itself. -- 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.