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: Wed, 30 Oct 2024 12:53:09 +0100 Organization: A noiseless patient Spider Lines: 26 Message-ID: References: <276fc9df-619b-4a10-b414-a04a74aa7378@att.net> <88e6a631-417a-4dd0-9443-a57116dcbd28@att.net> <7a1e34df-ffee-4d30-ae8c-2af5bcb1d932@att.net> <6a90a2e2-a4fa-4a8d-83e9-2e451fa8dd51@att.net> <0e5fb47d-60f7-42bb-beec-4a9661c807da@tha.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Wed, 30 Oct 2024 12:53:09 +0100 (CET) Injection-Info: dont-email.me; posting-host="9f8e7fe1992657fc233519f740544a28"; logging-data="2234777"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+rLnAZ39AW7cXDspECrKtOYWHqSeTSGKY=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:y6AK/xnbnOeoRkNvsnl49oxEjzI= Content-Language: en-US In-Reply-To: Bytes: 2758 On 29.10.2024 11:02, FromTheRafters wrote: > WM formulated the question : >> On 28.10.2024 21:51, FromTheRafters wrote: >>> WM explained : >>>> On 28.10.2024 15:07, FromTheRafters wrote: >>>>> WM was thinking very hard : >>>> >>>>>> The function NUF(x) = Number of Unit Fractions between 0 and x >>>>>> starts with 0 at 0. >>>>> >>>>> Followed by a discontinuity. >>>> >>>> No. ∀n ∈ ℕ: 1/n - 1/(n+1) > 0 holds everywhere. >>> >>> Not for n equal to zero. >> >> I said ∀n ∈ ℕ. 0 is no natural number. NUF(0) = 0. > > That is why your function is a step function with a discontinuity. NUF(0) = 0, NUF(1) = ℵo. Therefore NUF must grow but cannot grow by more than 1 at any point x of the real axis. Regards, WM