Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Richard Heathfield <rjh@cpax.org.uk>
Newsgroups: comp.theory
Subject: Re: Turing Machine computable functions apply finite string
 transformations to inputs VERIFIED FACT
Date: Tue, 29 Apr 2025 23:03:52 +0100
Organization: Fix this later
Lines: 42
Message-ID: <vuric8$2gjif$3@dont-email.me>
References: <vu6lnf$39fls$2@dont-email.me>
 <f0d3f2e87d9a4e0b0f445f60a33d529f41a4fcf7@i2pn2.org>
 <vuj55m$2lf64$10@dont-email.me> <vuj8h3$2uahf$3@dont-email.me>
 <vujfuu$35hcg$1@dont-email.me>
 <65dddfad4c862e6593392eaf27876759b1ed0e69@i2pn2.org>
 <vujlj0$3a526$1@dont-email.me> <vujln7$32om9$8@dont-email.me>
 <vujmmm$3a526$2@dont-email.me> <vujmrj$32om9$9@dont-email.me>
 <vujtcb$3gsgr$1@dont-email.me> <vuju44$3hnda$1@dont-email.me>
 <vuk47o$3qkbb$1@dont-email.me> <vuk6b6$3l184$1@dont-email.me>
 <vuls34$1bf1j$4@dont-email.me> <vun87k$2m24h$2@dont-email.me>
 <vunb06$2fjjl$5@dont-email.me> <vuo57j$3h5l9$2@dont-email.me>
 <vuoath$3ljma$1@dont-email.me> <vuohgi$3td7u$1@dont-email.me>
 <vuonh6$2g74$2@dont-email.me> <vupeor$qf60$1@dont-email.me>
 <vupu0r$18vrc$1@dont-email.me> <vuqj5u$1rljg$1@dont-email.me>
 <vuql8e$1svmd$1@dont-email.me> <vur7vd$2dvvs$1@dont-email.me>
 <vur9t9$2gjif$1@dont-email.me> <vurasr$2hkih$1@dont-email.me>
 <vurbgd$2gjif$2@dont-email.me> <vurgt8$2n355$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Wed, 30 Apr 2025 00:03:52 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="37e133e97ee7719e4a93228f44d9117b";
	logging-data="2641487"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+f3GClVJxOXqv59D4Rysw4qZ7KXFcmtUCHN8w3Z6qTlQ=="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:8P1FA7X3quHvk+AT5jpRuLgeOQA=
Content-Language: en-GB
In-Reply-To: <vurgt8$2n355$1@dont-email.me>
Bytes: 3116

On 29/04/2025 22:38, olcott wrote:

<snip>

> 
> int DD()
> {
>    int Halt_Status = HHH(DD);
>    if (Halt_Status)
>      HERE: goto HERE;
>    return Halt_Status;
> }
> 
> HHH is correct DD as non-halting BECAUSE THAT IS
> WHAT THE INPUT TO HHH(DD) SPECIFIES.

You're going round the same loop again.

Either your HHH() is a universal termination analyser or it 
isn't. If it isn't, it's irrelevant to the Halting Problem, and 
we can ignore it. If it is, however, then we know that it doesn't 
work for all inputs, even if (as you claim) it works for one.

<snip>

> DD <is> the Halting Problem counter-example input to HHH.
> 
>> for the same reason we can't devise a universally accurate 
>> termination analyser that executes the code to see what happens.
>>
> 
> There is no evidence of that.

Sure there is. Not just evidence, but an actual, rigorous, 
mathematical proof.

-- 
Richard Heathfield
Email: rjh at cpax dot org dot uk
"Usenet is a strange place" - dmr 29 July 1999
Sig line 4 vacant - apply within