Path: ...!weretis.net!feeder9.news.weretis.net!news.nk.ca!rocksolid2!i2pn2.org!.POSTED!not-for-mail From: joes Newsgroups: sci.math Subject: Re: The set of necessary FISONs Date: Fri, 31 Jan 2025 11:31:23 -0000 (UTC) Organization: i2pn2 (i2pn.org) Message-ID: References: <903de8e1-3538-4cfe-9f7a-6509eda47ab6@att.net> <3844edd7-0750-4418-bff6-2759817446b3@att.net> <27377646-137a-4f8f-a7bb-a75707b2da96@att.net> <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: Fri, 31 Jan 2025 11:31:23 -0000 (UTC) Injection-Info: i2pn2.org; logging-data="1994367"; 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: 2966 Lines: 24 Am Thu, 30 Jan 2025 23:32:52 +0100 schrieb WM: > On 30.01.2025 15:30, Richard Damon wrote: >> On 1/30/25 4:14 AM, WM wrote: >>> On 29.01.2025 13:46, Richard Damon wrote: >>> >>>> We can in fact build an infinite set of infinite sets of FISONs whose >>>> union is the set of Natural Numbers, >>> > If there is a set with U(F(n)) = ℕ, then it has a first element that is > not completely useless. Not necessarily. You may add the smallest segment that is not in the set to be unified (if the set does not include all). A sufficient set does not imply a necessary subset; indeed, a necessary set may not exist at all. It would require that a number existed in only one segment; however every segment is a subset of the successors. > But all F(n) can be shown to be completely > useless because infinitely many natnumbers are missing. Again: every single one, or even an arbitrary finite number. If you have inf. many segments, you obviously have inf. many numbers. -- 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.