Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: "Fred. Zwarts" <F.Zwarts@HetNet.nl>
Newsgroups: comp.theory
Subject: Re: Incorrect requirements --- Computing the mapping from the input
 to HHH(DD)
Date: Sat, 10 May 2025 10:44:55 +0200
Organization: A noiseless patient Spider
Lines: 99
Message-ID: <vvn3m8$3dv8d$11@dont-email.me>
References: <vv97ft$3fg66$1@dont-email.me> <vvgt36$1auqp$2@dont-email.me>
 <vvgtbe$1b0li$1@dont-email.me> <vvguot$1auqp$3@dont-email.me>
 <vvh0t2$1b939$1@dont-email.me> <vvhap5$1hp80$1@dont-email.me>
 <vvhf20$1ihs9$1@dont-email.me> <vvhfnd$1hvei$3@dont-email.me>
 <vvil99$1ugd5$1@dont-email.me> <vvinvp$1vglb$1@dont-email.me>
 <vviv75$222r6$1@dont-email.me> <vvj1fp$22a62$1@dont-email.me>
 <vvj2j6$23gk7$1@dont-email.me> <as9TP.251456$lZjd.93653@fx05.ams4>
 <87msbmeo3b.fsf@nosuchdomain.example.com> <vvjc9b$27753$1@dont-email.me>
 <87ecwyekg2.fsf@nosuchdomain.example.com> <vvjg6a$28g5i$3@dont-email.me>
 <d577d485d0f5dfab26315f54f91eb84f25eecc40@i2pn2.org>
 <87bjs2cyj6.fsf@nosuchdomain.example.com> <vvm69v$34ivd$1@dont-email.me>
 <87msblcg60.fsf@nosuchdomain.example.com> <vvmggq$3a34p$6@dont-email.me>
 <d07ca13226ecc137711110fd5cee56f39c2173a8@i2pn2.org>
 <vvmkiq$3bds9$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 10 May 2025 10:44:59 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="6132ef5c9a5712f5fb4e052234097a74";
	logging-data="3603725"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX19E0AdEvAj+4LCbqs5Qp3kn"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:WnsH2Dr6WGlt2/6WnizZH4/7Kk8=
Content-Language: nl, en-GB
In-Reply-To: <vvmkiq$3bds9$1@dont-email.me>
Bytes: 6458

Op 10.mei.2025 om 06:27 schreef olcott:
> On 5/9/2025 10:29 PM, Richard Damon wrote:
>> On 5/9/25 11:17 PM, olcott wrote:
>>> On 5/9/2025 10:12 PM, Keith Thompson wrote:
>>>> Mike Terry <news.dead.person.stones@darjeeling.plus.com> writes:
>>>>> On 09/05/2025 03:23, Keith Thompson wrote:
>>>>>> Richard Damon <richard@damon-family.org> writes:
>>>>>>> On 5/8/25 7:53 PM, olcott wrote:
>>>>>> [...]
>>>>>>>> void DDD()
>>>>>>>> {
>>>>>>>>      HHH(DDD);
>>>>>>>>      return;
>>>>>>>> }
>>>>>>>> We don't need to look at any of my code for me
>>>>>>>> to totally prove my point. For example when
>>>>>>>> the above DDD is correctly simulated by HHH
>>>>>>>> this simulated DDD cannot possibly reach its own
>>>>>>>> "return" instruction.
>>>>>>>
>>>>>>> And thus not correctly simulatd.
>>>>>>>
>>>>>>> Sorry, there is no "OS Exemption" to correct simulaiton;.
>>>>>> Perhaps I've missed something.  I don't see anything in the above
>>>>>> that
>>>>>> implies that HHH does not correctly simulate DDD.  Richard, you've 
>>>>>> read
>>>>>> far more of olcott's posts than I have, so perhaps you can clarify.
>>>>>> If we assume that HHH correctly simulates DDD, then the above code
>>>>>> is
>>>>>> equivalent to:
>>>>>>       void DDD()
>>>>>>       {
>>>>>>         DDD();
>>>>>>         return;
>>>>>>       }
>>>>>> which is a trivial case of infinite recursion.  As far as I can
>>>>>> tell,
>>>>>> assuming that DDD() is actually called at some point, neither the
>>>>>> outer execution of DDD nor the nested (simulated) execution of DDD
>>>>>> can reach the return statement.  Infinite recursion might either
>>>>>> cause a stack overflow and a probable program crash, or an unending
>>>>>> loop if the compiler implements tail call optimization.
>>>>>> I see no contradiction, just an uninteresting case of infinite
>>>>>> recursion, something that's well understood by anyone with a
>>>>>> reasonable level of programming experience.  (And it has nothing to
>>>>>> do with the halting problem as far as I can tell, though of course
>>>>>> olcott has discussed the halting problem elsewhere.)
>>>>>> Richard, what am I missing?
>>>>>
>>>>> Depends on what you've picked up on.
>>>>>
>>>>> Do you get that HHH's simulation is a /partial/ simulation?  HHH is
>>>>> free to simulate a few x86 instructions of DDD, and then simply
>>>>> abandon the simulation and return.  Since such a simulation is
>>>>> obviously NOT equivalent to a direct call to DDD, and above you argue
>>>>> that it is, I'd say you've missed that.
>>>>
>>>> I have not read the vast majority of olcott's post here.  For most
>>>> of the recent discussion I had with him, there was no mention of
>>>> partial simulation.  olcott finally said something about simulating
>>>> just a few instructions, but at the same time he finally indicated
>>>> that understanding his arguments would require an understanding of
>>>> x86 machine and/or assembly language.  That's when I bailed out.
>>>>
>>>> A "correct simulation", as I understand the term, would require fully
>>>> simulate the execution of DDD.  If DDD never halts, its simulation 
>>>> never
>>>> halts.  olcott seems to think that he's found a way around this that's
>>>> relevant to the Halting Problem, but I withdrew before getting to that
>>>> point.
>>>>
>>>
>>> It only need be a correct simulation until HHH sees the
>>> repeating pattern that would cause itself to never terminate.
>>
>> Right, but that pattern needs to be based on the fact that HHH is a 
>> program that can abort its simulation, and in fact WILL.
>>
>>>
>>> The best selling author of theory of computation textbooks
>>> agreed that I could quote his agreement with my words.
>>>
>>> <MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>
>>>      If simulating halt decider H correctly simulates its
>>>      input D until H correctly determines that its simulated D
>>>      would never stop running unless aborted then
>>>
>>>      H can abort its simulation of D and correctly report that D
>>>      specifies a non-halting sequence of configurations.
>>> </MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>
>>>
>>>
>>
> 
> *simulated D would never stop running unless aborted*
> means determining what would happen if this H never aborted.
But since D is aborted, this is a vacuous statement.
That is what H should take into account.