Path: ...!feeds.phibee-telecom.net!3.eu.feeder.erje.net!feeder.erje.net!news2.arglkargh.de!news.karotte.org!news.space.net!news.muc.de!.POSTED.news.muc.de!not-for-mail
From: Alan Mackenzie <acm@muc.de>
Newsgroups: sci.math
Subject: Re: The reality of sets, on a scale of 1 to 10 [Was: The non-existence of "dark numbers"]
Date: Sat, 22 Mar 2025 15:28:39 -0000 (UTC)
Organization: muc.de e.V.
Message-ID: <vrmkv7$308h$3@news.muc.de>
References: <vqrbtd$1chb7$2@solani.org>   <b3730bf7-bcd1-4698-b465-6d6ef190b29d@att.net> <vrgm1k$2s8c6$2@dont-email.me> <c81100d7-9354-4c8e-b216-e147cab9b41c@att.net> <vrhrlb$3ta8t$1@dont-email.me> <c0de7504-7d17-42f1-83e8-8767c0859c0c@att.net> <vrj5nh$12273$1@dont-email.me> <efbe60c5-6691-4fd6-8638-589fd95ec8a4@att.net> <vrkabi$233at$1@dont-email.me> <vrkca8$18dh$1@news.muc.de> <vrlt7r$3hfcp$3@dont-email.me> <vrmg0s$308h$1@news.muc.de> <vrmibq$5e2r$1@dont-email.me> <vrmj7b$5e2s$1@dont-email.me>
Injection-Date: Sat, 22 Mar 2025 15:28:39 -0000 (UTC)
Injection-Info: news.muc.de; posting-host="news.muc.de:2001:608:1000::2";
	logging-data="98577"; mail-complaints-to="news-admin@muc.de"
User-Agent: tin/2.6.4-20241224 ("Helmsdale") (FreeBSD/14.2-RELEASE-p1 (amd64))
Bytes: 2038
Lines: 21

Moebius <invalid@example.invalid> wrote:
> Am 22.03.2025 um 15:44 schrieb Moebius:
>> Am 22.03.2025 um 15:04 schrieb Alan Mackenzie:
>>> WM <wolfgang.mueckenheim@tha.de> wrote:

>>>> It leaves the cardinality unchanged because this notion is tantamount
>>>> to potential infinity.

>>> You're stuck in the 1880s.

>> Nope. Actually, his claim ist absurd nonsense. Es handelt sich bei WM um 
>> einen aufmerksamkeitsheischenden, geisteskranker Spinner.

> Hint: (a) Sets have /cardinality/. (b) There are no "potentially 
> infinite" sets. Either a set is infinite or not (i.e. finite).

Yes, very much so.  The term "potentially infinite" has no use in
mathematics.  Philosophers, etc., might cling to it, though.

-- 
Alan Mackenzie (Nuremberg, Germany).