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From: dbush <dbush.mobile@gmail.com>
Newsgroups: comp.theory
Subject: Re: DD simulated by HHH cannot possibly halt (Halting Problem)
Date: Mon, 14 Apr 2025 07:53:55 -0400
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On 4/14/2025 7:48 AM, olcott wrote:
> On 4/14/2025 3:28 AM, Mikko wrote:
>> On 2025-04-13 19:34:49 +0000, olcott said:
>>
>>> On 4/10/2025 6:27 PM, dbush wrote:
>>>> On 4/10/2025 7:26 PM, olcott wrote:
>>>>> On 4/10/2025 3:55 AM, Fred. Zwarts wrote:
>>>>>> Op 10.apr.2025 om 03:47 schreef olcott:
>>>>>>> On 4/9/2025 3:56 PM, dbush wrote:
>>>>>>>> On 4/9/2025 4:35 PM, olcott wrote:
>>>>>>>>> On 4/9/2025 1:58 PM, Fred. Zwarts wrote:
>>>>>>>>>> Op 09.apr.2025 om 19:29 schreef olcott:
>>>>>>>>>>>
>>>>>>>>>>> On 4/8/2025 10:31 AM, Fred. Zwarts wrote:
>>>>>>>>>>>> Op 08.apr.2025 om 17:13 schreef olcott:
>>>>>>>>>>>>> On 4/8/2025 2:45 AM, Fred. Zwarts wrote:
>>>>>>>>>>>>>> Op 08.apr.2025 om 06:33 schreef olcott:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> typedef void (*ptr)();
>>>>>>>>>>>>>>> int HHH(ptr P);
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> int DD()
>>>>>>>>>>>>>>> {
>>>>>>>>>>>>>>>    int Halt_Status = HHH(DD);
>>>>>>>>>>>>>>>    if (Halt_Status)
>>>>>>>>>>>>>>>      HERE: goto HERE;
>>>>>>>>>>>>>>>    return Halt_Status;
>>>>>>>>>>>>>>> }
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> int main()
>>>>>>>>>>>>>>> {
>>>>>>>>>>>>>>>    HHH(DD);
>>>>>>>>>>>>>>> }
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> *Simulating termination analyzer Principle*
>>>>>>>>>>>>>>> It is always correct for any simulating termination
>>>>>>>>>>>>>>> analyzer to stop simulating and reject any input that
>>>>>>>>>>>>>>> would otherwise prevent its own termination.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> In this case there is nothing to prevent, because the 
>>>>>>>>>>>>>> finite string specifies a program that halts.
>>>>>>>>>>>>>
>>>>>>>>>>>>> int DD()
>>>>>>>>>>>>> {
>>>>>>>>>>>>>    int Halt_Status = HHH(DD);
>>>>>>>>>>>>>    if (Halt_Status)
>>>>>>>>>>>>>      HERE: goto HERE;
>>>>>>>>>>>>>    return Halt_Status;
>>>>>>>>>>>>> }
>>>>>>>>>>>>>
>>>>>>>>>>>>> This stuff is simply over-your-head.
>>>>>>>>>>>>> HHH(DD) meets the above: *Simulating termination analyzer 
>>>>>>>>>>>>> Principle*
>>>>>>>>>>>>> Anyone with sufficient competence with the C programming 
>>>>>>>>>>>>> language
>>>>>>>>>>>>> will understand this.
>>>>>>>>>>>>>
>>>>>>>>>>>> Everyone with a little bit of C knowledge understands that 
>>>>>>>>>>>> if HHH returns with a value 0, then DDD halts.
>>>>>>>>>>>
>>>>>>>>>>> DDD CORRECTLY SIMULATED BY HHH
>>>>>>>>>>> NOT ANY OTHER DAMN DDD IN THE UNIVERSE NITWIT.
>>>>>>>>>>>
>>>>>>>>>> If HHH would correctly simulate DD (and the functions called 
>>>>>>>>>> by DD) then the simulated HHH would return to DD and DD would 
>>>>>>>>>> halt.
>>>>>>>>>
>>>>>>>>> Simply over your level of technical competence.
>>>>>>>>>
>>>>>>>>>> But HHH failed to complete the simulation of the halting program,
>>>>>>>>>
>>>>>>>>> HHH is only required to report on the behavior of its
>>>>>>>>> own correct simulation (meaning the according to the
>>>>>>>>> semantics of the C programming language) and would be
>>>>>>>>> incorrect to report on any other behavior.
>>>>>>>>
>>>>>>>> Which means HHH has conflicting requirements,
>>>>>>>
>>>>>>> No, it just means that the ones that you have
>>>>>>> been saying are f-cked up and no-one noticed this before.
>>>>>>>
>>>>>>>  > because to perform a
>>>>>>>  > correct simulation of its input it cannot halt itself, and 
>>>>>>> therefore
>>>>>>>  > can't report that.
>>>>>>> In other words you simply "don't believe in" the variant
>>>>>>> form of mathematical induction that HHH uses.
>>>>>>>
>>>>>>> A proof by induction consists of two cases. The first, the base 
>>>>>>> case, proves the statement for 𝑛=0 without assuming any knowledge 
>>>>>>> of other cases. The second case, the induction step, proves that 
>>>>>>> if the statement holds for any given case 𝑛=k, then it must also 
>>>>>>> hold for the next case 𝑛=k+1. These two steps establish that the 
>>>>>>> statement holds for every natural number 𝑛. The base case does 
>>>>>>> not necessarily begin with 𝑛=0, but often with 𝑛=1, and possibly 
>>>>>>> with any fixed natural number 𝑛=𝒩, establishing the truth of the 
>>>>>>> statement for all natural numbers 𝑛 ≥ 𝒩.   https:// 
>>>>>>> en.wikipedia.org/wiki/ Mathematical_induction
>>>>>>>
>>>>>> So the proof by induction shows that for any n HHH fails to 
>>>>>> complete the simulation. So, it has been proven that no HHH exists 
>>>>>> that is able to simulate correctly. It always aborts before it 
>>>>>> sees that the simulated HHH aborts as well.
>>>>>
>>>>> Yet again over-your-head.
>>>>> Unless the first HHH aborts
>>>>
>>>> Changing the input is not allowed.
>>>
>>> int DD()
>>> {
>>>    int Halt_Status = HHH(DD);
>>>    if (Halt_Status)
>>>      HERE: goto HERE;
>>>    return Halt_Status;
>>> }
>>>
>>> int main()
>>> {
>>>    HHH(DD);
>>> }
>>
>> That is changing the input. The subject line specifies DDD.
>>
> 
> Changing the subject line is allowed.
> 

Then maybe we should do as you do in such situations:

On 8/10/2024 2:11 PM, olcott wrote:
 > Changing the title indicates a reply that I can ignore.