Path: ...!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: WM Newsgroups: sci.math Subject: Re: Incompleteness of Cantor's enumeration of the rational numbers (extra-ordinary) Date: Sat, 30 Nov 2024 18:20:51 +0100 Organization: A noiseless patient Spider Lines: 26 Message-ID: References: <4a810760-86a1-44bb-a191-28f70e0b361b@att.net> <23311c1a-1487-4ee4-a822-cd965bd024a0@att.net> <71758f338eb239b7419418f49dfd8177c59d778b@i2pn2.org> <9510dd5dbc6edac4b3f35491638b7f27b25e6c43@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 30 Nov 2024 18:20:52 +0100 (CET) Injection-Info: dont-email.me; posting-host="ebfce87fb265da80d3fa3af64923c092"; logging-data="1945937"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX188ybM0zWT4Of3zj2xqxccWF76JTSZY2v0=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:s277J3w3KPfFAhYZDkzxK6EhKqI= In-Reply-To: <9510dd5dbc6edac4b3f35491638b7f27b25e6c43@i2pn2.org> Content-Language: en-US Bytes: 3110 On 30.11.2024 16:58, joes wrote: > Am Sat, 30 Nov 2024 13:19:46 +0100 schrieb WM: >> On 30.11.2024 12:54, FromTheRafters wrote: >> >>> Finite sets versus infinite sets. Finite ordered sets have a last >>> element which can be in the intersection of all previously considered >>> finite sets. Infinite ordered sets have no such last element. >> But they have infinitely many elements which contribute to the >> intersection. > For an intersection, the "smallest" set matters, which there isn't > in this infinite sequence, only a "biggest". If all sets are infinite, then there is no smaller set than an infinite set. > >> The intersection of the "finite initial segment" of endsegments is >> ∩{E(1), E(2), ..., E(k)} = E(k) >> is a function which remains infinite for all infinite endsegments. If >> all endsegments remain infinite forever, then this function remains >> infinite forever. > It does for all finite k. Of course. Only for finite k the endsegments are infinite. Regards, WM >