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From: "Fred. Zwarts" <F.Zwarts@HetNet.nl>
Newsgroups: comp.theory
Subject: Re: Everyone here seems to consistently lie about this
Date: Sat, 3 Aug 2024 16:01:32 +0200
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Op 03.aug.2024 om 15:48 schreef olcott:
> On 8/3/2024 3:06 AM, Mikko wrote:
>> On 2024-08-02 02:09:38 +0000, olcott said:
>>
>>> *This algorithm is used by all the simulating termination analyzers*
>>> <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>
>>>
>>> DDD is correctly emulated by HHH according to the x86
>>> language semantics of DDD and HHH including when DDD
>>> emulates itself emulating DDD
>>>
>>> *UNTIL*
>>>
>>> HHH correctly determines that never aborting this
>>> emulation would cause DDD and HHH to endlessly repeat.
>>
>> The determination is not correct. DDD is a halting computation, as
>> correctely determined by HHH1 or simly calling it from main. It is
>> not possible to correctly determine that ha haling computation is
>> non-halting, as is self-evdent from the meaning of the words.
>>
> 
> [Who here is too stupid to know that DDD correctly simulated
>   by HHH cannot possibly reach its own return instruction?]
> 
> void DDD()
> {
>    HHH(DDD);
>    return;
> }
> 

When it cannot possibly reach its own return instruction, it is an 
incorrect simulation, no matter how often you repeat the word 'correct'.
It does not help to repeat the same error hundreds of times, without any 
evidence.
It is clear that HHH that aborts also halts, so when the simulation of 
such a halting function cannot reach its return, the simulation fails.
It halts too soon. One cycle before the simulated HHH would abort and 
halt. Skipping the last few instructions makes the simulation incorrect.
DDD is a misleading and unneeded complication. It is easy to eliminate DDD:

        int main() {
          return HHH(main);
        }

This has the same problem. This proves that the problem is not in DDD, 
but in HHH, which halts when it aborts the simulation, but it decides 
that the simulation of itself does not halt.
It shows that HHH cannot possibly simulate itself correctly.