Path: ...!3.eu.feeder.erje.net!feeder.erje.net!usenet.goja.nl.eu.org!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Mikko Newsgroups: comp.theory Subject: Re: DDD correctly emulated by HHH is Correctly rejected as non-halting V2 Date: Fri, 26 Jul 2024 11:45:43 +0300 Organization: - Lines: 86 Message-ID: References: <8a6e6d9ff49aabe2525ce5729a439c807de4768a@i2pn2.org> <34Ocnd4voeWlDAn7nZ2dnZfqnPudnZ2d@brightview.co.uk> <056325e336f81a50f4fb9e60f90934eaac823d22@i2pn2.org> <210383b2ee318f68a96d94aec314ee8b93f79b7f@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 26 Jul 2024 10:45:44 +0200 (CEST) Injection-Info: dont-email.me; posting-host="54a4d2f1e21ba9e7e6a19f10fa449717"; logging-data="2912319"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19siU0fU6kY19qJ0KAr/uYr" User-Agent: Unison/2.2 Cancel-Lock: sha1:wTyugODWsd6cZDj3HsGUjXXwVFY= Bytes: 5316 On 2024-07-24 13:33:55 +0000, olcott said: > On 7/24/2024 3:57 AM, Mikko wrote: >> On 2024-07-23 13:31:35 +0000, olcott said: >> >>> On 7/23/2024 1:32 AM, 0 wrote: >>>> On 2024-07-22 13:46:21 +0000, olcott said: >>>> >>>>> On 7/22/2024 2:57 AM, Mikko wrote: >>>>>> On 2024-07-21 13:34:40 +0000, olcott said: >>>>>> >>>>>>> On 7/21/2024 4:34 AM, Mikko wrote: >>>>>>>> On 2024-07-20 13:11:03 +0000, olcott said: >>>>>>>> >>>>>>>>> On 7/20/2024 3:21 AM, Mikko wrote: >>>>>>>>>> On 2024-07-19 14:08:24 +0000, olcott said: >>>>>>>>>> >>>>>>>>>>> When we use your incorrect reasoning we would conclude >>>>>>>>>>> that Infinite_Loop() is not an infinite loop because it >>>>>>>>>>> only repeats until aborted and is aborted. >>>>>>>>>> >>>>>>>>>> You and your HHH can reason or at least conclude correctly about >>>>>>>>>> Infinite_Loop but not about DDD. Possibly because it prefers to >>>>>>>>>> say "no", which is correct about Infinte_loop but not about DDD. >>>>>>>>>> >>>>>>>>> >>>>>>>>> *Because this is true I don't understand how you are not simply lying* >>>>>>>>> int main >>>>>>>>> { >>>>>>>>>    DDD(); >>>>>>>>> } >>>>>>>>> >>>>>>>>> Calls HHH(DDD) that must abort the emulation of its input >>>>>>>>> or {HHH, emulated DDD and executed DDD} never stop running. >>>>>>>> >>>>>>>> You are the lying one. >>>>>>>> >>>>>>>> If HHH(DDD) abrots its simulation and returns true it is correct as a >>>>>>>> halt decider for DDD really halts. >>>>>>>> >>>>>>> >>>>>>> (b) We know that a decider is not allowed to report on the behavior >>>>>>> computation that itself is contained within. >>>>>> >>>>>> No, we don't. There is no such prohibition. >>>>>> >>>>> >>>>> Turing machines never take actual Turing machines as inputs. >>>>> They only take finite strings as inputs and an actual executing >>>>> Turing machine is not itself a finite string. >>>> >>>> The definition of a Turing machine does not say that a Turing machine >>>> is not a finite string. It is an abstract mathematical object without >>>> a specification of its exact nature. It could be a set or a finite >>>> string. Its exact nature is not relevant to the theory of computation, >>>> which only cares about certain properties of Turing machines. >>>> >>>>> Therefore It is not allowed to report on its own behavior. >>>> >>>> Anyway, that does not follow. The theory of Turing machines does not >>>> prohibit anything. >>>> >>>>> Another different TM can take the TM description of this >>>>> machine and thus accurately report on its actual behavior. >>>> >>>> If a Turing machine can take a description of a TM as its input >>>> or as a part of its input it can also take its own description. >>>> Every Turing machine can be given its own description as input >>>> but a Turing machine may interprete it as something else. >>>> >>> In this case we have two x86utm machines that are identical >>> except that DDD calls HHH and DDD does not call HHH1. >> >> That DDD calls HHH and DDD does not call HHH1 is not a difference >> between two unnamed turing machines. >> > > The same thing happens at the Peter Linz Turing Machine level > I will provide that more difficult example if and only if you > prove that you understand this one. However, Peter Linz does not call taht same thing a difference. -- Mikko