Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Simulation vs. Execution in the Halting Problem Date: Wed, 11 Jun 2025 17:33:52 -0500 Organization: A noiseless patient Spider Lines: 101 Message-ID: <102d082$28067$1@dont-email.me> References: <102c5nb$21qj7$2@dont-email.me> <602d915e3a80042ddac7f05fb389837ce3cefc12.camel@gmail.com> <102c7dj$226jq$1@dont-email.me> <0373fc8c6462341f655385edf6d4a0664a35981d.camel@gmail.com> <102ca1c$22pmt$1@dont-email.me> <85f876c4db96fb776dabc80c4208feed6aabc76d.camel@gmail.com> <102cdon$23jal$1@dont-email.me> <2e40a87aeb9e28ce23b5ebf3fcbf23dad6728a9b.camel@gmail.com> <102cg6f$246h5$1@dont-email.me> <822e204898d419545ca400a9088970f0b6a5107f.camel@gmail.com> <102ckje$25dg0$2@dont-email.me> <102cm0u$25dg0$3@dont-email.me> <610e2a54b66e8576b80bda3a0fe188d025b9798e.camel@gmail.com> <102cp0e$26clp$1@dont-email.me> <102crbv$26rt0$1@dont-email.me> <102ctbg$26rt0$2@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 12 Jun 2025 00:33:39 +0200 (CEST) Injection-Info: dont-email.me; posting-host="9f0ba097a1221e597ea76cc26b2e661a"; logging-data="2359495"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+3DF950fhpvEiIag9LQo2c" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:n0+G03Im6BO4p6UXJmIGlgozWC8= Content-Language: en-US X-Antivirus-Status: Clean X-Antivirus: Norton (VPS 250611-4, 6/11/2025), Outbound message In-Reply-To: On 6/11/2025 4:57 PM, wij wrote: > On Wed, 2025-06-11 at 16:44 -0500, olcott wrote: >> On 6/11/2025 4:23 PM, wij wrote: >>> On Wed, 2025-06-11 at 16:10 -0500, olcott wrote: >>>> On 6/11/2025 3:59 PM, wij wrote: >>>>> On Wed, 2025-06-11 at 15:30 -0500, olcott wrote: >>>>>> On 6/11/2025 2:45 PM, wij wrote: >>>>>>> On Wed, 2025-06-11 at 14:39 -0500, olcott wrote: >>>>>>>> On 6/11/2025 2:31 PM, wij wrote: >>>>>>>>> On Wed, 2025-06-11 at 14:14 -0500, olcott wrote: >>>>>>>>>> On 6/11/2025 1:25 PM, wij wrote: >>>>>>>>>>> On Wed, 2025-06-11 at 12:59 -0500, olcott wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>> Yes all other people (especially Dennis Bush) are saying >>>>>>>>>>>>>> that H(D) is required to report on the behavior of the >>>>>>>>>>>>>> direct execution of D() never noticing that this stupidly >>>>>>>>>>>>>> requires H(D) to report on the behavior of its caller. >>>>>>>>>>>>> >>>>>>>>>>>>> If the H above means the H that the HP refers to. The H is required to >>>>>>>>>>>>> report its argument's behavior (ie. by H(D)). But NOT required by simulation. >>>>>>>>>>>> >>>>>>>>>>>> It turns out that no one ever noticed that simulating halt >>>>>>>>>>>> deciders nullify the HP counter-example input in that this >>>>>>>>>>>> input cannot possibly reach its contradictory part. >>>>>>>>>>>> >>>>>>>>>>>>> The HP does not care what D does (simply to say). >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Everyone says that H(D) must re[port on the behavior of >>>>>>>>>>>> the direct execution of D(). >>>>>>>>>>> >>>>>>>>>>> That is what the HP asks. >>>>>>>>>>> >>>>>>>>>>>>> The HP only requires: H(D)==1 iff D() halts >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> int main() >>>>>>>>>>>> { >>>>>>>>>>>>         D(); // calls H(D) >>>>>>>>>>>> } >>>>>>>>>>>> >>>>>>>>>>>> Which requires H(D) to report on the behavior of its >>>>>>>>>>>> caller instead of reporting on the behavior that its >>>>>>>>>>>> input actually specifies. >>>>>>>>>>> >>>>>>>>>>> That is no problem. H does not care what D does inside (simply to say). >>>>>>>>>>> The HP simply asks for a H that "H(D)==1 iff D() halts". >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Which requires H to report on something that it cannot possibly see. >>>>>>>>> >>>>>>>>> On the contrary, what the HP proves is very useful. >>>>>>>>> >>>>>>>> >>>>>>>> I am not talking about the halting problem, I have always >>>>>>>> been talking about the conventional halting problem proof. >>>>>>>> THIS PROOF IS WRONG >>>>>>> >>>>>>> When talking about proof, we say it is valid or not. By doing so, we have >>>>>>> to unambiguously pose the problem and the derivation to the conclusion. >>>>>>> The HP proof just did that. >>>>>>> >>>>>> >>>>>> It may seem that way if you pay less than 100% >>>>>> complete attention. >>>>>> >>>>>> The HP proof depends on an *INPUT* that does >>>>>> the opposite of whatever value that H returns >>>>>> and no such *INPUT* can possibly exist. >>>>> >>>>> That is absolutely correct. No such *INPUT* (i.e. D) can possible exit is because >>>>> the H inside D does not exist at all. >>>>> So, if the H is assumed to exist, then D will exist to make H undecidable. >>>>> >>>> >>>> There is no *input* to any termination analyzer >>>> that can do the opposite of whatever value that >>>> this termination analyzer returns >>> >>> Your reinterpretation of of HP case is wrong. >>> Your D or H is not the case mention in the HP proof. >>> >> >> There cannot possibly exist any D mine or >> anyone else's that is encoded to do the opposite >> of whatever value that H returns. > > Why not? D and H are supposed to be TM (or C function). > If the D cannot do the opposite of whatever value that H returns, then > that D is not powerful enough to be a TM, not an interesting case. > Can you be your biological mother's biological father? It is for this same reason that the function's caller cannot simultaneously be its input. -- Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer