Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: olcott <polcott2@gmail.com>
Newsgroups: comp.theory,sci.logic
Subject: Re: Can an abort decider be defined that cannot be fooled by any
 pathological input?
Date: Tue, 26 Mar 2024 10:33:22 -0500
Organization: A noiseless patient Spider
Lines: 283
Message-ID: <utups3$1t1bi$1@dont-email.me>
References: <utoboa$5f03$1@dont-email.me> <utopik$89n1$1@dont-email.me>
 <uts4hn$15g1s$2@dont-email.me> <uts6bp$15q0v$1@dont-email.me>
 <uts79p$164d3$2@dont-email.me> <uts819$1682g$1@dont-email.me>
 <utschj$17h7c$1@dont-email.me> <utt2f8$32apl$1@i2pn2.org>
 <utt3qt$1cuoq$1@dont-email.me> <utt4h2$32apl$3@i2pn2.org>
 <utt5bv$1d2ks$2@dont-email.me> <utt5v2$32apk$11@i2pn2.org>
 <utt7e1$1dpmh$1@dont-email.me> <utt8fg$32apl$6@i2pn2.org>
 <utt8oq$1dv6f$2@dont-email.me> <uttank$32apk$12@i2pn2.org>
 <uttdbr$1evji$1@dont-email.me> <uttdpd$32apk$14@i2pn2.org>
 <uttfeo$1j1tv$1@dont-email.me> <utucdh$33t24$1@i2pn2.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Tue, 26 Mar 2024 16:33:24 +0100 (CET)
Injection-Info: dont-email.me; posting-host="b02d0a9d754c59878ed2d7beef0f0dc1";
	logging-data="2000242"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/v84AchdgXvXG0PSzKRiRo"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:vdTnpk9f0lYHcdhI0rVoE3hXLtg=
Content-Language: en-US
In-Reply-To: <utucdh$33t24$1@i2pn2.org>
Bytes: 13098

On 3/26/2024 6:43 AM, Richard Damon wrote:
> On 3/25/24 11:29 PM, olcott wrote:
>> On 3/25/2024 10:01 PM, Richard Damon wrote:
>>> On 3/25/24 10:53 PM, olcott wrote:
>>>> On 3/25/2024 9:08 PM, Richard Damon wrote:
>>>>> On 3/25/24 9:35 PM, olcott wrote:
>>>>>> On 3/25/2024 8:30 PM, Richard Damon wrote:
>>>>>>> On 3/25/24 9:12 PM, olcott wrote:
>>>>>>>> On 3/25/2024 7:47 PM, Richard Damon wrote:
>>>>>>>>> On 3/25/24 8:37 PM, olcott wrote:
>>>>>>>>>> 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 <is> 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.
>>>>>>>>>
>>>>>>>>> Neither am I.
========== REMAINDER OF ARTICLE TRUNCATED ==========