Path: ...!feeds.phibee-telecom.net!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Moebius Newsgroups: sci.math Subject: Re: Replacement of Cardinality Date: Mon, 26 Aug 2024 03:05:50 +0200 Organization: A noiseless patient Spider Lines: 47 Message-ID: References: <980a0ec7476c9dc5823e59b2969398bd39d9b91d@i2pn2.org> <8d5b0145-b30d-44d2-b4ff-b01976f7ca66@att.net> Reply-To: invalid@example.invalid MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Mon, 26 Aug 2024 03:05:52 +0200 (CEST) Injection-Info: dont-email.me; posting-host="4b1539e64c5d00758bb452bc01f8a2b3"; logging-data="2260792"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19kQmajAApuTMf9lzbLRX2/" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Zaej3aiRxU94+5+5rWlJg1Biysw= Content-Language: de-DE In-Reply-To: Bytes: 2637 Am 26.08.2024 um 00:04 schrieb Moebius: > Am 24.08.2024 um 06:30 schrieb Jim Burns: > Seems you really don't get it. (*sigh*) > > Without proof of > >          1. Ex(raimex(x)) > and >      2. AxAy(raimex(x) & raimex(y) -> x = y) > > we may not use the "definition" > >          x = the_raimex :<-> rational(x) & imaginative(x) & > experiencing(x) & a_being(x) > > In other words, we are not allowed to talk about _the_ raimex (not > having a proof that there is exactly one such entity, i.e. exactly > one x such that x is a raimex). If we would, say, allow for the "definition" x = 1/0 :<-> 0 * x = 1 and hence the "lemma" ~Ex(x = 1/0) , we would get: Ax(x =/= 1/0) . Then by specification (AE) we would get: 1/0 =/= 1/0 from this, and then by (EI): Ex(x =/= x) . Not a desirable result. (That's why _one_ of the rules for proper definitions of constants requires an existence proof first.)