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: wij Newsgroups: comp.theory Subject: Re: Cantor Diagonal Proof Date: Sun, 06 Apr 2025 15:15:51 +0800 Organization: A noiseless patient Spider Lines: 42 Message-ID: <45bb7521c3bb68fe5fd47d10ee93a03de17f8d47.camel@gmail.com> References: <7EKdnTIUz9UkpXL6nZ2dnZfqn_ednZ2d@brightview.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Injection-Date: Sun, 06 Apr 2025 09:15:52 +0200 (CEST) Injection-Info: dont-email.me; posting-host="ed44edb85b9ccc9a724188d6920c2cc1"; logging-data="379582"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19IUn6QJvi6G/v37HgoPdBA" User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Cancel-Lock: sha1:id6FhfyH+zFahD6tzcHIazLFnrg= In-Reply-To: Bytes: 3205 On Sun, 2025-04-06 at 06:43 +0000, Lawrence D'Oliveiro wrote: > On Sun, 6 Apr 2025 07:27:43 +0100, Richard Heathfield wrote: >=20 > > On 06/04/2025 06:40, Lawrence D'Oliveiro wrote: > >=20 > > > On Sat, 5 Apr 2025 09:07:22 +0100, Richard Heathfield wrote: > > >=20 > > > > But to be computable, numbers must be computed in a finite number o= f > > > > steps. > > >=20 > > > =E2=80=9CComputable Number: A number which can be computed to any num= ber of > > > digits desired by a Turing machine.=E2=80=9D > > >=20 > > > > >=20 > > "The =E2=80=9Ccomputable=E2=80=9D numbers may be described briefly as t= he real numbers > > whose expressions as a decimal are calculable by finite means." - Alan > > Turing. > >=20 > > And therefore, to be computable, numbers must be computed in a finite > > number of steps. >=20 > I would say you are quoting Turing out of context. By your=20 > (mis)interpretation of his words, even something like 1/3 is an=20 > incomputable number, since its =E2=80=9Cexpressions as a decimal are not= =20 > calculable by finite means=E2=80=9D. Simply put, repeating decimals are irrational. https://sourceforge.net/projects/cscall/files/MisFiles/RealNumber2-en.txt/d= ownload All your doubt should be addressed in the file of the link. > Turing would not have been so dumb as to have his definition of=20 > computability depend on something as trivial as the choice of number base= ..