Path: ...!news.mixmin.net!weretis.net!feeder8.news.weretis.net!reader5.news.weretis.net!news.solani.org!.POSTED!not-for-mail From: WM Newsgroups: sci.math Subject: Re: The non-existence of "dark numbers" Date: Sat, 15 Mar 2025 09:56:31 +0100 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 15 Mar 2025 08:56:30 -0000 (UTC) Injection-Info: solani.org; logging-data="1585025"; mail-complaints-to="abuse@news.solani.org" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:hh6vxhnxil0Vmke98CcFtWxJ41k= Content-Language: en-US In-Reply-To: X-User-ID: eJwNycEBwCAIA8CVREmAcQRk/xHa+x4OhWVKUDEYqZaZ0mHtE89zsYl8q8p81b27A3netIJ/hGenpzkYHmkfe7UWQQ== Bytes: 3053 Lines: 51 On 15.03.2025 00:11, Alan Mackenzie wrote: > WM wrote: >> ℕ_def contains all numbers the subtraction of which from ℕ does not >> result in the empty set. > > What does "which" refer to? It refers to the numbers. An Englishman should comprehend that. > To N_def or to a > member of the "all numbers"? That is one and the same. > > Assuming the former, then if X is any proper subset of N, N \ X is > non-empty. So by this "definition", N_def is any proper subset of N. No, ℕ_def contains only definable numbers. > >> Obviously the subtraction of all numbers which cannot empty ℕ cannot >> empty ℕ. Therefore |ℕ \ ℕ_def| = ℵo. Do you agree? > > Of course not. Then you cannot think logically. > It all depends on the X from which N_def is formed. If > X is N \ {1}, Then its elements are mostly undefined as individuals. >> Yes, of course. But ℕ_def is not completed by its definition. > > You haven't defined N_def - what appears above is not a coherent > definition. It is coherent enough. Every element has a finite FISON. ℕ is infinite. Therefore it cannot be emptied by the elements of ℕ_def and also not by ℕ_def. >>> The tending takes place, but not in a "place". > >> No? Tending means that hitherto undefined natural numbers become >> defined. That takes place on the ordinal line. > > "Hitherto" ("bis jetzt" in German) is purely a time based adverb. The > natural numbers are not defined in a time based sequence. They are > defined all together. Not the defined numbers. Regards, WM