Path: ...!news.nobody.at!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory,sci.logic Subject: Re: Can an abort decider be defined that cannot be fooled by any pathological input? Date: Mon, 25 Mar 2024 19:37:19 -0500 Organization: A noiseless patient Spider Lines: 152 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Tue, 26 Mar 2024 01:37:19 +0100 (CET) Injection-Info: dont-email.me; posting-host="b02d0a9d754c59878ed2d7beef0f0dc1"; logging-data="1477276"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19LNrDusKKM4h9BjnaMCrQn" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:a8LVXknDMyHtJl6JTec1r1V7I10= Content-Language: en-US In-Reply-To: Bytes: 6939 On 3/25/2024 7:22 PM, Richard Damon wrote: > On 3/25/24 8:11 PM, olcott wrote: >> On 3/25/2024 6:47 PM, Richard Damon wrote: >>> On 3/25/24 1:33 PM, olcott wrote: >>>> On 3/25/2024 11:16 AM, Fred. Zwarts wrote: >>>>> Op 25.mrt.2024 om 17:04 schreef olcott: >>>>>> On 3/25/2024 10:48 AM, Fred. Zwarts wrote: >>>>>>> Op 25.mrt.2024 om 16:17 schreef olcott: >>>>>>>> On 3/24/2024 3:51 AM, Fred. Zwarts wrote: >>>>>>>>> Op 24.mrt.2024 om 05:55 schreef olcott: >>>>>>>>>> Can an abort decider be defined that cannot be fooled by any >>>>>>>>>> pathological input? >>>>>>>>>> >>>>>>>>>> 01 int D(ptr x)  // ptr is pointer to int function >>>>>>>>>> 02 { >>>>>>>>>> 03   int Halt_Status = H(x, x); >>>>>>>>>> 04   if (Halt_Status) >>>>>>>>>> 05     HERE: goto HERE; >>>>>>>>>> 06   return Halt_Status; >>>>>>>>>> 07 } >>>>>>>>>> 08 >>>>>>>>>> 09 void main() >>>>>>>>>> 10 { >>>>>>>>>> 11   H(D,D); >>>>>>>>>> 12 } >>>>>>>>>> >>>>>>>>>> Of all of the elements of the set of H(D,D) where H simulates its >>>>>>>>>> input there are matched pairs of otherwise identical elements >>>>>>>>>> that >>>>>>>>>> only differ by whether they abort their simulation or not. >>>>>>>>>> >>>>>>>>>> The half of these that don't abort are incorrect because all >>>>>>>>>> deciders >>>>>>>>>> must halt. This makes the other half correct about the >>>>>>>>>> abort/no abort >>>>>>>>>> decision. >>>>>>>>> >>>>>>>>> No. The other, aborting, half is just wrong, because it aborts >>>>>>>>> when it is not needed. So, the half that aborts is wrong and it >>>>>>>>> may be argued that it is better to not abort something that >>>>>>>>> halts on its own and that >>>>>>>> >>>>>>>> At least two software engineers with masters degrees in computer >>>>>>>> science >>>>>>>> disagree. >>>>>>> >>>>>>> Two is not many, considering that with Google for any invalid >>>>>>> idea it is easy to find a several people with a master degree >>>>>>> supporting it. >>>>>>> >>>>>>>> Exactly what are you software engineering skills? >>>>>>> >>>>>>> I have been professionally programming since 1986 in several >>>>>>> languages. (Non professionally I started programming in 1975). >>>>>>> Since about 1990 I programmed in C and since about 2000 in C++. >>>>>>> >>>>>>> >>>>>>>> I have been a professional C++ software engineer since Y2K. >>>>>>> >>>>>>> I'm sorry to hear that olcott has been so smart, but now he does >>>>>>> not even sees what even a beginner sees. >>>>>> >>>>>> Can D correctly simulated by H terminate normally? >>>>>> 01 int D(ptr x)  // ptr is pointer to int function >>>>>> 02 { >>>>>> 03   int Halt_Status = H(x, x); >>>>>> 04   if (Halt_Status) >>>>>> 05     HERE: goto HERE; >>>>>> 06   return Halt_Status; >>>>>> 07 } >>>>>> 08 >>>>>> 09 void main() >>>>>> 10 { >>>>>> 11   H(D,D); >>>>>> 12 } >>>>>> >>>>>> *Execution Trace* >>>>>> Line 11: main() invokes H(D,D); >>>>>> >>>>>> *keeps repeating* (unless aborted) >>>>>> Line 03: simulated D(D) invokes simulated H(D,D) that simulates D(D) >>>>> >>>>> Even a beginner sees that, if the H that aborts is chosen, >>>>> simulated H(D,D) aborts and returns false (unless aborted). So >>>>> simulated D halts (unless aborted). >>>>> >>>> >>>> I am estimating that you must be fibbing about your programming skill. >>>> The D simulated by any implementation of H (that aborts or does not >>>> abort its simulation) shown above cannot possibly reach its own line 04 >>>> also shown above. >>>> >>> >>> But that isn't the question. >>> >> >> *That the abort decision question* > > But you agreed that a correct abort decider oly NEEDS to abort its > simulation if the correct simulation by a pure correct simulator of the > input given to H (which doesn't change, so for this case, still calls > that original H) will never reach a final state. > >> >>> The question is does that machine described by the input Halt when >>> run, or, alternatively, does its correct simulation (not just by H) >>> run forever (and thus needs to be aborted)? >>> >> >> Since you know that H(D,D) must abort its simulation to prevent its >> own infinite execution I don't understand why you would lie about it. > > But an H that doesn't abort and an H that does abort are looking at > different inputs "D", since you agree that the behavior of D changes > based on the H that it is using. > Not at all. Of the infinite set of every possible implementation of H where H(D,D) simulates its input everyone that chose to abort is necessarily correct. I don't understand why you persist in lying about this. >> >> I really want to get on to the next step and see if any input can >> fool an abort decider into making the wrong abort decision. > > But you need to get this step right first. > >> >> Perhaps you already know that you are not up to this challenge? > > No, it seems that YOU are not up to it, as you can't seem to understand > the error that you are making. > > You keep on lying to yourself about what your requirements are. > I am not the one that keeps using the strawman deception to change the subject away from H(D,D) an abort decider for the above D. >> >>> Correct simulation refering to a simulation of the EXACT input given >>> to H, that calls the H that you claim to be giving the correct answer >>> (and not the "correct simulator") >> > -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer