Path: ...!feeds.phibee-telecom.net!2.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Liar detector: Fred, Richard, Joes and Alan --- Ben's agreement Date: Sat, 13 Jul 2024 06:57:59 -0500 Organization: A noiseless patient Spider Lines: 126 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 13 Jul 2024 13:57:59 +0200 (CEST) Injection-Info: dont-email.me; posting-host="52398669a80ff5113c36343403a598c9"; logging-data="3758667"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18r3zoGg8xLBV9ZliBP7nhO" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:S9WF7Zpr9xbgyEb0gIS80H0ATxc= Content-Language: en-US In-Reply-To: Bytes: 6234 On 7/13/2024 2:46 AM, Mikko wrote: > On 2024-07-12 13:07:59 +0000, olcott said: > >> On 7/12/2024 2:55 AM, Mikko wrote: >>> On 2024-07-11 14:16:34 +0000, olcott said: >>> >>>> On 7/11/2024 1:50 AM, Mikko wrote: >>>>> On 2024-07-10 13:37:30 +0000, olcott said: >>>>> >>>>>> On 7/10/2024 2:18 AM, Mikko wrote: >>>>>>> On 2024-07-09 14:14:16 +0000, olcott said: >>>>>>> >>>>>>>> On 7/9/2024 1:14 AM, Mikko wrote: >>>>>>>>> On 2024-07-08 17:36:58 +0000, olcott said: >>>>>>>>> >>>>>>>>>> On 7/8/2024 11:16 AM, Fred. Zwarts wrote: >>>>>>>>>>> Op 08.jul.2024 om 18:07 schreef olcott: >>>>>>>>>>>> >>>>>>>>>>>> Try to show how infinity is one cycle too soon. >>>>>>>>>>>> >>>>>>>>>>> You believe that two equals infinity. >>>>>>>>>> >>>>>>>>>> void Infinite_Loop() >>>>>>>>>> { >>>>>>>>>>    HERE: goto HERE; >>>>>>>>>> } >>>>>>>>>> >>>>>>>>>> void Infinite_Recursion() >>>>>>>>>> { >>>>>>>>>>    Infinite_Recursion(); >>>>>>>>>> } >>>>>>>>>> >>>>>>>>>> void DDD() >>>>>>>>>> { >>>>>>>>>>    HHH(DDD); >>>>>>>>>> } >>>>>>>>>> >>>>>>>>>> Two cycles is enough to correctly determine that none >>>>>>>>>> of the above functions correctly emulated by HHH can >>>>>>>>>> possibly halt. >>>>>>>>>> >>>>>>>>>> That you don't see this is ignorance or deception. >>>>>>>>> >>>>>>>>> There is an important detail that determines whether an infinite >>>>>>>>> execution can be inferred. That is best illustrated by the >>>>>>>>> following >>>>>>>>> examples: >>>>>>>>> >>>>>>>>> void Finite_Loop() >>>>>>>>> { >>>>>>>>>   int x = 10000; >>>>>>>>> HERE: >>>>>>>>>   if (x > 0) { >>>>>>>>>     x--; >>>>>>>>>     goto HERE; >>>>>>>>>   } >>>>>>>>> } >>>>>>>>> >>>>>>>>> void Finite_Recursion(int n) >>>>>>>>> { >>>>>>>>>   if (n > 0) { >>>>>>>>>     Finite_Recursion(n + 1); >>>>>>>>>   } >>>>>>>>> } >>>>>>>>> >>>>>>>>> void DDD() >>>>>>>>> { >>>>>>>>>   HHH(DDD); // HHH detects recursive simulation and then >>>>>>>>> simulates no more >>>>>>>>> } >>>>>>>>> >>>>>>>>> The important difference is that in my examples there is a >>>>>>>>> conditional >>>>>>>>> instruction that can (and does) prevent infinite exectuion. >>>>>>>>> >>>>>>>> >>>>>>>> When we ask: >>>>>>>> Does the call from DDD emulated by HHH to HHH(DDD) return? >>>>>>> >>>>>>> Why would anyone ask that? A question should make clear its topic. >>>>>>> Instead one could ask whether HHH can fully emulate DDD if that is >>>>>>> what one wants to know. Or one may think that HHH and DDD are so >>>>>>> unimteresting that there is no point to ask anyting about them. >>>>>> >>>>>> A correct emulator can correctly any correct x86 instructions. >>>>>> When it emulates non-halting code then itself does not halt. >>>>> >>>>> Not quite right but should be easy to fix. There should be a verb >>>>> before "any", >>>>> for example "execute". Of course there still is a probelm with the >>>>> meaning >>>>> "any correct x86 instructions". Intel may publish a new x86 >>>>> processor that has >>>>> instructios that the emulator cannot know but are nevertheless >>>>> correct x86 >>>>> instructions because Intel says so. In the second sentence "it" >>>>> should be used >>>>> istead of "itself". >>>>> >>>> >>>> Intel has already done this and they call this x64. >>>> A 1907 Model-T Ford cannot have upgrades and still >>>> be a 1907 model-T Ford. Likewise for the x86 language. >>> >>> A new version of a 1907 Model-T Ford is possible and can have the >>> same name >>> except that the "1907" must be replaced as it refers to the year. >>> That the >>> "Model-T" is also replaced is a free chioce of Ford. >>> >>> Likewise Intel is free to call a new processor whatever they want to >>> call it. >>> >> >> The x86 language is a fixed constant. > > Where has Intel promised so? > Backward compatibility requires it. https://en.wikipedia.org/wiki/X86_assembly_language#:~:text=x86%20assembly%20language%20is%20the,was%20launched%20in%20April%201972. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer