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: Keith Thompson Newsgroups: comp.theory Subject: Re: Cantor Diagonal Proof Date: Mon, 14 Apr 2025 17:49:56 -0700 Organization: None to speak of Lines: 34 Message-ID: <878qo22qq3.fsf@nosuchdomain.example.com> References: <875xjfd5rs.fsf@nosuchdomain.example.com> <87tt6zblzl.fsf@nosuchdomain.example.com> <0920ac6e196c1cebeff36d8b9431ee12a7b3d527@i2pn2.org> <74db303c1d07ba0fdf70f1b20f5f7d6e04667665@i2pn2.org> <4f2f706fdbd8bb237b4bfbc750f65482db6e96c7@i2pn2.org> <84c84545ad9509384f5378553217346b12512a97@i2pn2.org> <87h62rg1rx.fsf@nosuchdomain.example.com> <87cydffviw.fsf@nosuchdomain.example.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Date: Tue, 15 Apr 2025 02:50:01 +0200 (CEST) Injection-Info: dont-email.me; posting-host="a2350407d780bb528cb106f4e5e26372"; logging-data="2640926"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+wlL2iYRgao0liAoRxwdFr" User-Agent: Gnus/5.13 (Gnus v5.13) Cancel-Lock: sha1:SMKgrTzURmvwofEMZ0KdGR5sWXQ= sha1:xqR9CTGQ6iYSR1uTOfpjXgDjCqI= Bytes: 3124 Lawrence D'Oliveiro writes: > On Sun, 13 Apr 2025 17:15:35 -0700, Keith Thompson wrote: > >> Lawrence D'Oliveiro writes: >>> >>> On Sun, 13 Apr 2025 15:00:34 -0700, Keith Thompson wrote: >>>> >>>> The Cantor construction *assumes* the existence of such a list ... >>> >>> Clearly, then, there must not be any objections to the creation of such >>> a list, other than the Cantor construction itself. >> >> Why would you assume that? > > Because I don’t see any objections to Cantor making that assumption. What assumption? Cantor did not assume that there are no objections to the creation of such a list, other than the Cantor construction itself. Cantor started by assuming the existence of such a list, and showed that that assumption leads to a contradiction, thereby proving that no such list exists. There's no reason to think that there couldn't be other proofs of the nonexistence of such a list. Do you question the validity of reductio ad absurdum? I asked questions in my previous article; you snipped them. If you're going to do continue doing that, I won't waste more time discussing this with you. -- Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com void Void(void) { Void(); } /* The recursive call of the void */