Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Incorrect requirements --- Computing the mapping from the input to HHH(DD) Date: Fri, 9 May 2025 22:24:43 -0500 Organization: A noiseless patient Spider Lines: 106 Message-ID: References: <87msbmeo3b.fsf@nosuchdomain.example.com> <87ecwyekg2.fsf@nosuchdomain.example.com> <87bjs2cyj6.fsf@nosuchdomain.example.com> <87r00xchn5.fsf@nosuchdomain.example.com> <23a27379d226b7b3b9f8c303a492f66edc9019ff.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sat, 10 May 2025 05:24:44 +0200 (CEST) Injection-Info: dont-email.me; posting-host="7be348abb5bc2ec0a70724586a3ca680"; logging-data="3476633"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18chZFOInHhZKSrTjMGtjqJ" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:WJwnTAVTPNyFi1I5wgDJ6uqln2c= X-Antivirus-Status: Clean In-Reply-To: <23a27379d226b7b3b9f8c303a492f66edc9019ff.camel@gmail.com> Content-Language: en-US X-Antivirus: Norton (VPS 250509-6, 5/9/2025), Outbound message On 5/9/2025 10:13 PM, wij wrote: > On Fri, 2025-05-09 at 19:40 -0700, Keith Thompson wrote: >> olcott writes: >>> On 5/9/2025 4:40 PM, Richard Heathfield wrote: >>>> On 09/05/2025 21:15, olcott wrote: >>>>> On 5/9/2025 3:07 PM, Richard Heathfield wrote: >>>>>> On 09/05/2025 20:46, olcott wrote: >>>>>>> We have not begun to get into any of those points. >>>>>>> We are only asking can DDD correctly simulated >>>>>>> by any HHH that can exist ever reach its own >>>>>>> "return" instruction. >>>>>> >>>>>> DDD can't be correctly simulated by itself (which is effectively >>>>>> what you're trying to do when you fire up the simulation from >>>>>> inside DDD). >>>>> >>>>> How the Hell did you twist my words to say that? >>>> I haven't touched your words. What I have done is to observe that >>>> DDD's /only/ action is to call a simulator. Since DDD isn't itself a >>>> simulator, there is nothing to simulate except a call to a >>>> simulator. >>>> It's recursion without a base case - a rookie error. >>>> HHH cannot successfully complete its task, because it never regains >>>> control after the first recursion. To return, it must abort the >>>> simulation, which means the simulation fails. >>>> >>>>> void DDD() >>>>> { >>>>>    HHH(DDD); >>>>>    return; >>>>> } >>>>> >>>>> When 1 or more statements of DDD are correctly >>>>> simulated by HHH then this correctly simulated >>>>> DDD cannot possibly reach its own “return statement”. >>>> On what grounds can you persuade an extraordinarily sceptical >>>> readership that HHH 'correctly simulated' DDD? >>> >>> Any competent C programmer can see that >>> the call from DDD to HHH(DDD) (its own simulator) >>> is equivalent to infinite recursion. >>> >>> On 5/8/2025 8:30 PM, Keith Thompson wrote: >>>> Assuming that HHH(DDD) "correctly simulates" DDD, and assuming it >>>> does nothing else, your code would be equivalent to this: >>>> >>>>      void DDD(void) { >>>>          DDD(); >>>>          return; >>>>      } >>>> >>>> Then the return statement (which is unnecessary anyway) will never be >>>> reached.  In practice, the program will likely crash due to a stack >>>> overflow, unless the compiler implements tail-call optimization, in >>>> which case the program might just run forever -- which also means the >>>> unnecessary return statement will never be reached. >> >> I had not intended to post again, but I feel the need to make >> a clarification. >> >> I acknowledged that the return statement would never be reached >> *given the assumption* that HHH correctly simulates DDD.  Given >> that assumption, a call to DDD() should be equivalent to a call >> to HHH(DDD). >> >> I did not address whether the assumption is valid.  I merely >> temporarily accepted it for the sake of discussion, just as I would >> accept that if I were ten feet tall I would bump my head against >> the ceiling in my house. >> >> The discussion I had with olcott did not reach the point of >> discussing *how* HHH could correctly simulate DDD, or whether it >> would even be logically possible for it to do so.  I also did not >> address any issues of partial simulation, where olcott claims that >> HHH can "accurately simulate" only a few x86 instructions rather >> than simulating its entire execution.  I did not participate in >> any discussion that would require knowledge of x86 machine or >> assembly code.  (I have no doubt that I could learn x86 machine >> and assembly code reasonably well if motivated to do so, but I am >> not so motivated.) >> >> What I acknowledged was barely more than "if HHH correctly simulates >> DDD, then HHH correctly simulates DDD".  (My understanding from >> posts by others, whom I presume to be sufficiently knowledgeable, >> is that HHH logically cannot accurately simulate DDD.)  I would >> prefer that olcott refrain from using my words to support any of >> his arguments beyond the scope of what he and I directly discussed. > > Don't know why you people stick on the 'simulation' stuff so long. > The HP simply asks for such an H (in function form. POOH does not > resemble TM): > H(D)=1 if D() halt. > H(D)=0 if D() not halt. My invention of a simulating termination analyzer shows exactly how to compute the mapping that the input that HHH(DD) specifies into a correct answer for the halting problem's otherwise impossible input. All rebuttals are based on failing to compute this mapping correctly. -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer