Path: ...!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder2.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 Date: Sun, 17 Nov 2024 18:38:00 +0100 Organization: A noiseless patient Spider Lines: 35 Message-ID: References: <1fca3a53-1cb4-4fd2-85b6-85e9b69ca23b@att.net> <97304048-24f5-4625-82a7-d17427f2f6e3@att.net> <65febd06-662b-4fa4-9aa8-f7353a79a110@att.net> <157a949d-6c19-4693-8cee-9e067268ae45@att.net> <8165b44b-1ba5-429d-8317-0b043b214b53@att.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 17 Nov 2024 18:38:02 +0100 (CET) Injection-Info: dont-email.me; posting-host="cec0708a7b2b5d7f33db81afdc17ed34"; logging-data="798048"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18h+xvKyJ1Pe2wNPVc1mpsZnM8Yks4W+kc=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:fswd6pcpUcSxAUC75+L6UO9bgaI= Content-Language: en-US In-Reply-To: Bytes: 3224 On 17.11.2024 17:59, FromTheRafters wrote: > WM pretended : >> On 17.11.2024 12:38, FromTheRafters wrote: >>> WM presented the following explanation : >>>> On 17.11.2024 12:01, FromTheRafters wrote: >>>>> WM was thinking very hard : >>>>>> On 16.11.2024 22:33, Moebius wrote: >>>>>> >>>>>>> For example "aleph_0 - aleph_0" is not defined. >>>>>> >>>>>> Small wonder. ℵo means only infinitely many: |ℕ|, |ℚ|, and many >>>>>> others. >>>>>> |ℕ|-|ℕ| however is defined. >>>>> >>>>> No, it is not. >>>> >>>> If sets are invariable then ℕ \ ℕ is empty. >>>> If |ℕ| concerns only the elements of ℕ, then |ℕ|-|ℕ|= 0. >>> >>> So, you're saying that if I take aleph_zero natural numbers and I >>> remove the aleph_zero odd numbers from consideration in a new set, I >>> will have a new emptyset instead of E? >> >> Try to understand. "aleph_0 - aleph_0" is not defined. > > Try to understand that |N| equals aleph_zero. Of course. ℵo equals |ℕ|, equals |ℚ|, equals all countable sets. It is simply another name for infinitely "many". |ℕ| however is a fixed infinite number. Note that sets are invariable. Regards, WM