Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Lawrence D'Oliveiro Newsgroups: comp.theory Subject: Re: Cantor Diagonal Proof Date: Fri, 11 Apr 2025 00:29:56 -0000 (UTC) Organization: A noiseless patient Spider Lines: 21 Message-ID: References: <7EKdnTIUz9UkpXL6nZ2dnZfqn_ednZ2d@brightview.co.uk> <875xjfd5rs.fsf@nosuchdomain.example.com> <87tt6zblzl.fsf@nosuchdomain.example.com> <0920ac6e196c1cebeff36d8b9431ee12a7b3d527@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Fri, 11 Apr 2025 02:29:56 +0200 (CEST) Injection-Info: dont-email.me; posting-host="ad3a35b5daa6ea169a187dfe6eb4c019"; logging-data="193788"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+K8d8kQ1EigPs6G8BS/Xr8" User-Agent: Pan/0.162 (Pokrosvk) Cancel-Lock: sha1:9wrQLSgLIrcAYaU8e1+J/IqDKbA= On Thu, 10 Apr 2025 10:37:49 +0300, Mikko wrote: > On 2025-04-10 00:50:10 +0000, Lawrence D'Oliveiro said: > >> On Mon, 7 Apr 2025 20:48:27 -0400, Richard Damon wrote: >> >>> The paper clearly talks about the process continuing indefinitely. >> >> Note the key point about any computation of a computable number is that >> the answer *converges* to the exact result in the limit. As you compute >> more and more digits, the discrepancy between your approximation and >> the correct answer can be made as close to zero as you like, just as >> long as you don’t ask for it to be zero. >> >> The Cantor construction does not converge. > > If it is a computable number it does converge. That’s a key point of my proof: if it converges, then the number is already in the list. The only way it can come up with a number not in the list is by never converging.