Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: dbush Newsgroups: comp.theory Subject: Re: Halting Problem: What Constitutes Pathological Input Date: Wed, 7 May 2025 07:46:33 -0400 Organization: A noiseless patient Spider Lines: 184 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Wed, 07 May 2025 13:46:33 +0200 (CEST) Injection-Info: dont-email.me; posting-host="3013d96e0ac4b7dd359f7afe652f4ce0"; logging-data="1059862"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+Zejg0kKMIfV2g2qq6R9O2" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:/hohUAiISCo7KOHKNvzY0zlglXU= In-Reply-To: Content-Language: en-US On 5/7/2025 12:55 AM, olcott wrote: > On 5/6/2025 9:48 PM, dbush wrote: >> On 5/6/2025 10:44 PM, olcott wrote: >>> On 5/6/2025 9:34 PM, Richard Damon wrote: >>>> On 5/6/25 9:47 PM, olcott wrote: >>>>> On 5/6/2025 5:43 PM, Richard Damon wrote: >>>>>> On 5/6/25 11:10 AM, olcott wrote: >>>>>>> On 5/6/2025 4:26 AM, Mikko wrote: >>>>>>>> On 2025-05-05 18:14:25 +0000, olcott said: >>>>>>>> >>>>>>>>> On 5/5/2025 11:16 AM, dbush wrote: >>>>>>>>>> On 5/5/2025 12:13 PM, Mr Flibble wrote: >>>>>>>>>>> On Mon, 05 May 2025 11:58:50 -0400, dbush wrote: >>>>>>>>>>> >>>>>>>>>>>> On 5/5/2025 11:51 AM, olcott wrote: >>>>>>>>>>>>> On 5/5/2025 10:17 AM, Mr Flibble wrote: >>>>>>>>>>>>>> What constitutes halting problem pathological input: >>>>>>>>>>>>>> >>>>>>>>>>>>>> Input that would cause infinite recursion when using a >>>>>>>>>>>>>> decider of the >>>>>>>>>>>>>> simulating kind. >>>>>>>>>>>>>> >>>>>>>>>>>>>> Such input forms a category error which results in the >>>>>>>>>>>>>> halting problem >>>>>>>>>>>>>> being ill-formed as currently defined. >>>>>>>>>>>>>> >>>>>>>>>>>>>> /Flibble >>>>>>>>>>>>> >>>>>>>>>>>>> I prefer to look at it as a counter-example that refutes >>>>>>>>>>>>> all of the >>>>>>>>>>>>> halting problem proofs. >>>>>>>>>>>> >>>>>>>>>>>> Which start with the assumption that the following mapping >>>>>>>>>>>> is computable >>>>>>>>>>>> and that (in this case) HHH computes it: >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Given any algorithm (i.e. a fixed immutable sequence of >>>>>>>>>>>> instructions) X >>>>>>>>>>>> described as with input Y: >>>>>>>>>>>> >>>>>>>>>>>> A solution to the halting problem is an algorithm H that >>>>>>>>>>>> computes the >>>>>>>>>>>> following mapping: >>>>>>>>>>>> >>>>>>>>>>>> (,Y) maps to 1 if and only if X(Y) halts when executed >>>>>>>>>>>> directly >>>>>>>>>>>> (,Y) maps to 0 if and only if X(Y) does not halt when >>>>>>>>>>>> executed >>>>>>>>>>>> directly >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>>> int DD() >>>>>>>>>>>>> { >>>>>>>>>>>>>     int Halt_Status = HHH(DD); >>>>>>>>>>>>>     if (Halt_Status) >>>>>>>>>>>>>       HERE: goto HERE; >>>>>>>>>>>>>     return Halt_Status; >>>>>>>>>>>>> } >>>>>>>>>>>>> >>>>>>>>>>>>> https://github.com/plolcott/x86utm >>>>>>>>>>>>> >>>>>>>>>>>>> The x86utm operating system includes fully operational HHH >>>>>>>>>>>>> and DD. >>>>>>>>>>>>> https://github.com/plolcott/x86utm/blob/master/Halt7.c >>>>>>>>>>>>> >>>>>>>>>>>>> When HHH computes the mapping from *its input* to the >>>>>>>>>>>>> behavior of DD >>>>>>>>>>>>> emulated by HHH this includes HHH emulating itself >>>>>>>>>>>>> emulating DD. This >>>>>>>>>>>>> matches the infinite recursion behavior pattern. >>>>>>>>>>>>> >>>>>>>>>>>>> Thus the Halting Problem's "impossible" input is correctly >>>>>>>>>>>>> determined >>>>>>>>>>>>> to be non-halting. >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Which is a contradiction.  Therefore the assumption that the >>>>>>>>>>>> above >>>>>>>>>>>> mapping is computable is proven false, as Linz and others >>>>>>>>>>>> have proved >>>>>>>>>>>> and as you have *explicitly* agreed is correct. >>>>>>>>>>> >>>>>>>>>>> The category (type) error manifests in all extant halting >>>>>>>>>>> problem proofs >>>>>>>>>>> including Linz.  It is impossible to prove something which is >>>>>>>>>>> ill- formed >>>>>>>>>>> in the first place. >>>>>>>>>>> >>>>>>>>>>> /Flibble >>>>>>>>>> >>>>>>>>>> All algorithms either halt or do not halt when executed >>>>>>>>>> directly. Therefore the problem is not ill formed. >>>>>>>>> >>>>>>>>> When BOTH Boolean RETURN VALUES are the wrong answer >>>>>>>>> THEN THE PROBLEM IS ILL-FORMED. Self-contradiction must >>>>>>>>> be screened out as semantically incorrect. >>>>>>>> >>>>>>>> Irrelevant. One of the boolean values (the one not returned) is the >>>>>>>> right one as can be determined e.g. with an UTM. >>>>>>>> >>>>>>>>>> You only get something that appears that way when a false >>>>>>>>>> assumption is made, namely that the halting function is >>>>>>>>>> computable. >>>>>>>>> >>>>>>>>> The mapping from the input HHH(DD) finite string of >>>>>>>>> machine code to DOES SPECIFY RECURSIVE EMULATION >>>>>>>>> THAT WOULD PREVENT DD FROM EVER HALTING. >>>>>>>> >>>>>>>> No, it does not. HHH returns 0 and DD halts. >>>>>>>> >>>>>>> >>>>>>> You can't show the detailed steps of the execution >>>>>>> trace of DD emulated by HHH (according to the rules >>>>>>> of the x86 language) where DD halts because you are wrong. >>>>>> >>>>>> Because a trace of DD correctly emulatd by HHH doesn't exist as >>>>>> HHH doesn't correctly emulate DD >>>>>> >>>>> >>>>> Show what the execution trace of DD emulated by HHH >>>>> according to the rules of the x86 language should be >>>>> >>>> >>>> Since HHH doesn't do that, >>> >>> and you cannot possibly point out what the correct >>> steps should be >> >> >> The steps that UTM / HHH1 takes that HHH does not, > > which are the steps of DD emulated by HHH > according to the rules of the x86 language False, as you yourself have admitted on the record that it does not: On 5/5/2025 8:24 AM, dbush wrote: > On 5/4/2025 11:03 PM, dbush wrote: >> On 5/4/2025 10:05 PM, olcott wrote: >>> On 5/4/2025 7:23 PM, Richard Damon wrote: >>>> But HHH doesn't correct emulated DD by those rules, as those rules >>>> do not allow HHH to stop its emulation, >>> >>> Sure they do you freaking moron... >> >> Then show where in the Intel instruction manual that the execution of >> any instruction other than a HLT is allowed to stop instead of >> executing the next instruction. >> >> Failure to do so in your next reply, or within one hour of your next >> post on this newsgroup, will be taken as you official on-the-record >> admission that there is no such allowance and that HHH does NOT >> correctly simulate DD. > > Let the record show that Peter Olcott made the following post in this > newsgroup after the above message: > > On 5/4/2025 11:04 PM, olcott wrote: > > D *WOULD NEVER STOP RUNNING UNLESS* > > indicates that professor Sipser was agreeing > > to hypotheticals AS *NOT CHANGING THE INPUT* > > > > You are taking > > *WOULD NEVER STOP RUNNING UNLESS* > > to mean *NEVER STOPS RUNNING* that is incorrect. > > And has made no attempt after over 9 hours to show where in the Intel > instruction manual that execution is allowed to stop after any ========== REMAINDER OF ARTICLE TRUNCATED ==========