Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: dbush Newsgroups: comp.theory Subject: Re: DDD simulated by HHH cannot possibly halt (Halting Problem) --- mindless robots Date: Mon, 14 Apr 2025 21:30:11 -0400 Organization: A noiseless patient Spider Lines: 26 Message-ID: References: <852f89c9196e0261b8156050fea4572fe886933f@i2pn2.org> <17c452bb03454b8defc9c6d21cc9f2b5d124447a@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 15 Apr 2025 03:30:11 +0200 (CEST) Injection-Info: dont-email.me; posting-host="7a693fffeb8cb3d93ca8829962a38503"; logging-data="2701947"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19T/x2Udgtdyb/vpoHh9hLw" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:5B47uEinO3/p+BfflbQpuNQSX9k= In-Reply-To: Content-Language: en-US Bytes: 3181 On 4/14/2025 9:23 PM, olcott wrote: > On 4/14/2025 7:33 AM, joes wrote: >> Am Mon, 14 Apr 2025 06:46:20 -0500 schrieb olcott: >>> Such an HHH works fine when the input DD is not attempting to do the >>> opposite of whatever this HHH reports. This is not a problem though. DD >>> merely changes its own behavior through the pathological self-reference >>> that it implements. >> DD doesn’t change anything. It is completeley determined by the return >> value of HHH. Either it halts or it doesn’t, and HHH returns the wrong >> result. >> >>> Then HHH simply reports on this changed behavior. HHH need not even know >>> that DD is calling itself. It only need to know that the behavior of DD >>> would prevent its own termination. >> If HHH reports on what DD *would* do *if* HHH returned the other value, >> that’s changing the input. (HHH doesn’t „know” anything at all.) >> > > Hypothetical freaking possibilities of alternatives is > not a very difficult thing. I don't understand why its so > hard for you. > Because your hypothetical possibilities change the input. Changing the input, even hypothetically, is not allowed.