Path: ...!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: WM Newsgroups: sci.math Subject: Re: The non-existence of "dark numbers" Date: Wed, 19 Mar 2025 10:39:38 +0100 Organization: A noiseless patient Spider Lines: 19 Message-ID: References: <5d4e93233370e24f89417e1dd62b44763cbc47f5@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Wed, 19 Mar 2025 10:39:39 +0100 (CET) Injection-Info: dont-email.me; posting-host="254e2dea4bce2ede65bafe0735807cc4"; logging-data="619059"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+sfKQUG13j57ZeATaFAt4Pjl1bfKWZIg8=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:TtoLOvkUfu00bIx7qGqKdvGwl9A= Content-Language: en-US In-Reply-To: <5d4e93233370e24f89417e1dd62b44763cbc47f5@i2pn2.org> Bytes: 2456 On 18.03.2025 21:40, joes wrote: > Am Tue, 18 Mar 2025 16:34:21 +0100 schrieb WM: >> On 18.03.2025 12:57, Alan Mackenzie wrote: >>> WM wrote: >> >>>> The set of FISONs is an inductive set. But it is not ℕ because ∀n ∈ >>>> UF: |ℕ \ {1, 2, 3, ..., n}| = ℵo. >>> >>> That "because" doesn't hold >> >> Because you say so? That's not significant. Even if you can't understand >> the correct argument, it is decisive: ℕ_def contains all numbers the >> subtraction of which from ℕ does not result in the empty set. Obviously >> the subtraction of all numbers which cannot empty ℕ cannot empty ℕ. > There are many such sets: N\{0}, N\{1}, N\{2}, ... ℕ_def contains only numbers with FISONs. N\{0} is not a FISON. Regards, WM