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) Date: Sun, 13 Apr 2025 17:04:59 -0400 Organization: A noiseless patient Spider Lines: 68 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 13 Apr 2025 23:04:58 +0200 (CEST) Injection-Info: dont-email.me; posting-host="acf86990c0c55813e5914ba20d3f0f2e"; logging-data="3474503"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+Qg85/ealXrOOD7trDo9+7" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:2qJvll1SpUuuH/3VBE2/biWfNxg= Content-Language: en-US In-Reply-To: Bytes: 4258 On 4/13/2025 5:02 PM, olcott wrote: > On 4/13/2025 2:54 PM, dbush wrote: >> On 4/13/2025 3:52 PM, olcott wrote: >>> On 4/13/2025 4:18 AM, joes wrote: >>>> Am Wed, 09 Apr 2025 15:35:30 -0500 schrieb olcott: >>>>> On 4/9/2025 1:58 PM, Fred. Zwarts wrote: >>>>>> Op 09.apr.2025 om 19:29 schreef olcott: >>>>>>> On 4/8/2025 10:31 AM, Fred. Zwarts wrote: >>>>>>>> Op 08.apr.2025 om 17:13 schreef olcott: >>>>>>>>> On 4/8/2025 2:45 AM, Fred. Zwarts wrote: >>>>>>>>>> Op 08.apr.2025 om 06:33 schreef olcott: >>>> >>>>>>>>>>> *Simulating termination analyzer Principle* >>>>>>>>>>> It is always correct for any simulating termination analyzer to >>>>>>>>>>> stop simulating and reject any input that would otherwise >>>>>>>>>>> prevent >>>>>>>>>>> its own termination. >>>>>>>>>> >>>>>>>>>> In this case there is nothing to prevent, because the finite >>>>>>>>>> string >>>>>>>>>> specifies a program that halts. >>>>>>>>> >>>>>>>>> int DD() >>>>>>>>> { >>>>>>>>>     int Halt_Status = HHH(DD); >>>>>>>>>     if (Halt_Status) >>>>>>>>>       HERE: goto HERE; >>>>>>>>>     return Halt_Status; >>>>>>>>> } >>>>>>>>> HHH(DD) meets the above: *Simulating termination analyzer >>>>>>>>> Principle* >>>>>>>>> >>>>>>>> Everyone with a little bit of C knowledge understands that if HHH >>>>>>>> returns with a value 0, then DDD halts. >>>>>>> >>>>>>> DDD CORRECTLY SIMULATED BY HHH NOT ANY OTHER DAMN DDD IN THE >>>>>>> UNIVERSE >>>>>>> NITWIT. >>>>>>> >>>>>> If HHH would correctly simulate DD (and the functions called by DD) >>>>>> then the simulated HHH would return to DD and DD would halt. >>>>>> But HHH failed to complete the simulation of the halting program, >>>>> >>>>> HHH is only required to report on the behavior of its own correct >>>>> simulation (meaning the according to the semantics of the C >>>>> programming >>>>> language) and would be incorrect to report on any other behavior. >>> >>>> Such as what actually happens when you run it? >>>> >>> >>> Why do you insist on dishonestly ignoring the pathological >>> self-reference difference? >>> >> >> Why do you insist on dishonestly ignoring that the input to HHH halts >> when executed directly? > > Because this stupidly ignores the difference > of pathological self-reference. > But I want to know if any arbitrary algorithm X with input Y will halt when executed directly. If I had an H that could tell me that in *all* possible cases, I could show that all truths are provable. If you're not interested in such an H, then you have no interest in making all true statements provable.