Path: ...!eternal-september.org!feeder2.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: WM Newsgroups: sci.math Subject: Re: How many different unit fractions are lessorequal than all unit fractions? (infinitary) Date: Sat, 2 Nov 2024 10:59:04 +0100 Organization: A noiseless patient Spider Lines: 35 Message-ID: References: <6a90a2e2-a4fa-4a8d-83e9-2e451fa8dd51@att.net> <30dffbdf129483f7b61e3284d1e7bf2ad2e5ea16@i2pn2.org> <9ca97f4a24ae1e3041583265125cf860d2fada11@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 02 Nov 2024 10:59:05 +0100 (CET) Injection-Info: dont-email.me; posting-host="2f7bdf3e653733b4727fe893b0085bd6"; logging-data="3912821"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18yyOfUcZxbwXRunc2UnoNTlfNGm/2JEjo=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:dZnHJKT98oL6GQcXNhW46Uh3adg= In-Reply-To: Content-Language: en-US Bytes: 3316 On 01.11.2024 22:53, FromTheRafters wrote: > WM explained on 11/1/2024 : >> On 01.11.2024 19:39, FromTheRafters wrote: >>> WM formulated the question : >> >>>>> Infinite subsets don't do that for you, even if you wish really hard. >>>> >>>> They cannot evade if they are invariable. >>> >>> Sets don't change. >> >> Therefore the elements do not depend on us and our knowledge. "If I >> find x, then I can find x + 1" is not relevant. "For every x (that I >> find) there is x + 1" is no relevant. All elements are there, >> independent of what we know or do. Therefore the first and the last >> are also there independent of us. If they weren't, their existence >> would depend on some circumstances and could change. > > Circumstances like "there is no last element"? That means, there is always another element. Potential infinity. > the set > of denominators have no largest element to 'start' with. If all unit fractions are existing, then a smallest unit fraction is existing. If NUF(x) has grown to ℵ₀ at x₀, then ℵ₀ unit fractions must be between 0 and x₀. Hence at least ℵ₀ points with ℵ₀ intervals of uncountably many points must be between 0 and x₀. That cannot happen at x₀ = 0. Is that too hard to understand? Regards, WM