Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Mikko Newsgroups: comp.theory Subject: Re: Anyone with sufficient knowledge of C knows that DD specifies non-terminating behavior to HHH Date: Sun, 23 Feb 2025 12:59:26 +0200 Organization: - Lines: 138 Message-ID: References: <3b8a5f4be53047b2a6c03f9678d0253e137d3c40@i2pn2.org> <5cd9bc55c484f10efd7818ecadf169a11fcc58e1@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 23 Feb 2025 11:59:26 +0100 (CET) Injection-Info: dont-email.me; posting-host="43abbc3ed4ab8776d31eef797b453f0f"; logging-data="508697"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/1F0Fq3oJjJm7I8uC1EfBE" User-Agent: Unison/2.2 Cancel-Lock: sha1:zbOHwMNtSRhJaouI8wBr0Nl9nUU= On 2025-02-22 16:11:31 +0000, olcott said: > On 2/22/2025 3:04 AM, Mikko wrote: >> On 2025-02-21 22:35:16 +0000, olcott said: >> >>> On 2/21/2025 2:18 AM, Mikko wrote: >>>> On 2025-02-20 21:31:44 +0000, olcott said: >>>> >>>>> On 2/20/2025 2:38 AM, Mikko wrote: >>>>>> On 2025-02-20 00:31:33 +0000, olcott said: >>>>>> >>>>>>> On 2/19/2025 3:01 AM, Mikko wrote: >>>>>>>> On 2025-02-18 11:26:25 +0000, olcott said: >>>>>>>> >>>>>>>>> On 2/18/2025 3:24 AM, Mikko wrote: >>>>>>>>>> On 2025-02-17 09:05:42 +0000, Fred. Zwarts said: >>>>>>>>>> >>>>>>>>>>> Op 16.feb.2025 om 23:51 schreef olcott: >>>>>>>>>>>> On 2/16/2025 4:30 PM, joes wrote: >>>>>>>>>>>>> Am Sun, 16 Feb 2025 15:58:14 -0600 schrieb olcott: >>>>>>>>>>>>>> On 2/16/2025 2:02 PM, joes wrote: >>>>>>>>>>>>>>> Am Sun, 16 Feb 2025 13:24:14 -0600 schrieb olcott: >>>>>>>>>>>>>>>> On 2/16/2025 10:35 AM, joes wrote: >>>>>>>>>>>>>>>>> Am Sun, 16 Feb 2025 06:51:12 -0600 schrieb olcott: >>>>>>>>>>>>>>>>>> On 2/15/2025 2:49 AM, Mikko wrote: >>>>>>>>>>>>>>>>>>> On 2025-02-14 12:40:04 +0000, olcott said: >>>>>>>>>>>>>>>>>>>> On 2/14/2025 2:58 AM, Mikko wrote: >>>>>>>>>>>>>>>>>>>>> On 2025-02-14 00:07:23 +0000, olcott said: >>>>>>>>>>>>>>>>>>>>>> On 2/13/2025 3:20 AM, Mikko wrote: >>>>>>>>>>>>>>>>>>>>>>> On 2025-02-13 04:21:34 +0000, olcott said: >>>>>>>>>>>>>>>>>>>>>>>> On 2/12/2025 4:04 AM, Mikko wrote: >>>>>>>>>>>>>>>>>>>>>>>>> On 2025-02-11 14:41:38 +0000, olcott said: >>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>> DD  correctly simulated by HHH cannot possibly terminate normally. >>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>> That claim has already shown to be false. Nothing above shows that >>>>>>>>>>>>>>>>>>> HHH does not return 0. If it does DD also returns 0. >>>>>>>>>>>>>>>>>> When we are referring to the above DD simulated by HHH and not >>>>>>>>>>>>>>>>>> trying to get away with changing the subject to some other DD >>>>>>>>>>>>>>>>>> somewhere else >>>>>>>>>>>>>>>>> such as one that calls a non-aborting version of HHH >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> then anyone with sufficient knowledge of C programming knows that no >>>>>>>>>>>>>>>>>> instance of DD shown above simulated by any corresponding instance >>>>>>>>>>>>>>>>>> of HHH can possibly terminate normally. >>>>>>>>>>>>>>>>> Well, then that corresponding (by what?) HHH isn’t a decider. >>>>>>>>>>>>>>>> I am focusing on the isomorphic notion of a termination analyzer. >>>>>>>>>>>>>>> (There are other deciders that are not termination analysers.) >>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> A simulating termination analyzer correctly rejects any input that >>>>>>>>>>>>>>>> must be aborted to prevent its own non-termination. >>>>>>>>>>>>>>> Yes, in particular itself is not such an input, because we *know* that >>>>>>>>>>>>>>> it halts, because it is a decider. You can’t have your cake and eat it >>>>>>>>>>>>>>> too. >>>>>>>>>>>>>> I am not even using the confusing term "halts". >>>>>>>>>>>>>> Instead I am using in its place "terminates normally". >>>>>>>>>>>>>> DD correctly simulated by HHH cannot possibly terminate normally. >>>>>>>>>>>>> What’s confusing about „halts”? I find it clearer as it does not imply >>>>>>>>>>>>> an ambiguous „abnormal termination”. How does HHH simulate DD >>>>>>>>>>>>> terminating abnormally, then? Why doesn’t it terminate abnormally >>>>>>>>>>>>> itself? >>>>>>>>>>>>> You can substitute the term: the input DD to HHH does not need to be >>>>>>>>>>>>> aborted, because the simulated decider terminates. >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> typedef void (*ptr)(); >>>>>>>>>>>> int HHH(ptr P); >>>>>>>>>>>> >>>>>>>>>>>> int DD() >>>>>>>>>>>> { >>>>>>>>>>>>   int Halt_Status = HHH(DD); >>>>>>>>>>>>   if (Halt_Status) >>>>>>>>>>>>     HERE: goto HERE; >>>>>>>>>>>>   return Halt_Status; >>>>>>>>>>>> } >>>>>>>>>>>> >>>>>>>>>>>> int main() >>>>>>>>>>>> { >>>>>>>>>>>>   HHH(DD); >>>>>>>>>>>> } >>>>>>>>>>>> >>>>>>>>>>>> Every simulated input that must be aborted to >>>>>>>>>>>> prevent the non-termination of HHH is stipulated >>>>>>>>>>>> to be correctly rejected by HHH as non-terminating. >>>>>>>>>>>> >>>>>>>>>>> A very strange and invalid stipulation. >>>>>>>>>> >>>>>>>>>> It merely means that the words do not have their ordinary meaning. >>>>>> >>>>>> Those two comments are not discussed below. >>>>>> >>>>>>>>> Unless HHH(DD) aborts its simulation of DD itself cannot possibly >>>>>>>>> terminate normally. >>>>>>>> >>>>>>>> That cannot be determined without examination of HHH, which is not in the >>>>>>>> scope of OP. >>>>>>> >>>>>>> I have given everyone here all of the complete source >>>>>>> code for a few years >>>>>> >>>>>> True but irrelevant. OP did not specify that HHH means that particular >>>>>> code. >>>>>> >>>>> >>>>> Every post that I have been talking about for two or >>>>> more years has referred to variations of that same code. >>>> >>>> OP had a pointer of that code but didn's state that that code is a part >>>> of the problem. OP did not spacify any range for variation. >>>> >>> >>> I have only been talking about variations of the same code >>> as HHH(DD) for two years. Do you understand that one sentence? >> >> I understnd the sentence except the word "variations". What is the >> range of "variations"? >> > > Good you are being completely reasonable. > There are at least two algorithms the current > one that was also the original one is easiest to > understand. This algorithm essentially spots the > equivalent of infinite recursion. The code provides > all of the details. > >> Anyway OP did not specify that HHH is restricted to those "variations". >> Another undefined word of OP is "cannot". About a person it may mean >> that one does not do what one wants to do but a program does not want. >> > > HHH is exactly as specified. Assuming otherwise is silly. The words "as specified" when nothing is specified are not a good use of the language. -- Mikko