Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: FromTheRafters Newsgroups: sci.math Subject: Re: The set of necessary FISONs Date: Mon, 03 Mar 2025 12:01:59 -0500 Organization: Peripheral Visions Lines: 26 Message-ID: References: <4bce9826fcd4c68b4785aabc83de9394eae61402@i2pn2.org> <2a62cfa0db610ef9bb26903f8e9417e96e1bfa57@i2pn2.org> <4a9f36181152eb4df4a819f7abcdaae5de1f3d09@i2pn2.org> <5ce95a2f51d41e6d0f8d88635f2dcf1108d79f19@i2pn2.org> <6617ea3ee1afb665fd59e25dbaa6c7944b960b26@i2pn2.org> Reply-To: erratic.howard@gmail.com MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 03 Mar 2025 18:02:02 +0100 (CET) Injection-Info: dont-email.me; posting-host="849b3933fc85904023c16d4453ce09ec"; logging-data="1482699"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/l+LamH/6o1aG/YO1HKo37T0e+eixQ2gA=" Cancel-Lock: sha1:J/muCvHMOcrh/zFsXFEo6/EoEh4= X-Newsreader: MesNews/1.08.06.00-gb X-ICQ: 1701145376 Bytes: 3050 WM formulated the question : > On 03.03.2025 12:58, joes wrote: >> Am Mon, 03 Mar 2025 09:48:16 +0100 schrieb WM: > >>>> Ah no, you're shifting the quantifier there. >>> That is allowed if Zermelo can do it. >> He can't. > > But it has been accepted that with all defined elements the set is defined. >>> By induction Zermelo produces the set. Quantifier shift, obviously >>> allowed by Zermelo. There is no other way to construct an infinite set. >> A quantifier shift is never a valid deduction (even though the resultant >> sentence may be true otherwise). > > Zermelo has no other deduction. The set is constructed by its elements. >> >>>> The set of sets of FISONs that can be removed together does not contain >>>> the set of all FISONs (although it does contain the infinite sets of >>>> the odd or even FISONs). >>> In exactly the same way as Z₀ is constructed by its elements, the set of >>> removable FISONs is constructed by its elements. >> And in the same way Z_0 doesn't contain the set of all elements. > > Of course not. It is the set of all elements. Discrete elements.