Re: Defining a correct simulating halt decider

Op 12.sep.2024 om 13:08 schreef olcott:

On 9/12/2024 3:07 AM, Mikko wrote:

On 2024-09-11 22:35:07 +0000, olcott said:
>

On 9/11/2024 11:23 AM, Fred. Zwarts wrote:

Op 11.sep.2024 om 13:49 schreef olcott:

On 9/10/2024 6:50 AM, Fred. Zwarts wrote:

Op 09.sep.2024 om 20:19 schreef olcott:

On 9/8/2024 9:53 AM, Mikko wrote:

On 2024-09-07 13:57:00 +0000, olcott said:
>

On 9/7/2024 3:29 AM, Mikko wrote:

On 2024-09-07 05:12:19 +0000, joes said:
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Am Fri, 06 Sep 2024 06:42:48 -0500 schrieb olcott:

On 9/6/2024 6:19 AM, Mikko wrote:

On 2024-09-05 13:24:20 +0000, olcott said:

On 9/5/2024 2:34 AM, Mikko wrote:

On 2024-09-03 13:00:50 +0000, olcott said:

On 9/3/2024 5:25 AM, Mikko wrote:

On 2024-09-02 16:38:03 +0000, olcott said:
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A halt decider is a Turing machine that computes the mapping from
its finite string input to the behavior that this finite string
specifies.

>
A halt decider needn't compute the full behaviour, only whether
that behaviour is finite or infinite.
>

New slave_stack at:1038c4 Begin Local Halt Decider Simulation

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Local Halt Decider: Infinite Recursion Detected Simulation Stopped
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Hence  HHH(DDD)==0 is correct

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Nice to see that you don't disagree with what said.
Unvortunately I can't agree with what you say.
HHH terminates,
os DDD obviously terminates, too. No valid

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DDD emulated by HHH never reaches it final halt state.

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If that iis true it means that HHH called by DDD does not return and
therefore is not a ceicder.

The directly executed HHH is a decider.

What does simulating it change about that?

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If the simulation is incorrect it may change anything.
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PATHOLOGICAL RELATIONSHIPS CHANGE BEHAVIOR
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PATHOLOGICAL RELATIONSHIPS CHANGE BEHAVIOR
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>
However, a correct simultation faithfully imitates the original
behaviour.
>

>
_DDD()
[00002172] 55         push ebp      ; housekeeping
[00002173] 8bec       mov ebp,esp   ; housekeeping
[00002175] 6872210000 push 00002172 ; push DDD
[0000217a] e853f4ffff call 000015d2 ; call HHH(DDD)
[0000217f] 83c404     add esp,+04
[00002182] 5d         pop ebp
[00002183] c3         ret
Size in bytes:(0018) [00002183]
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A correct emulation obeys the x86 machine code even
if this machine code catches the machine on fire.
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It is impossible for an emulation of DDD by HHH to
reach machine address 00002183 AND YOU KNOW IT!!!
>

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It seems olcott also knows that HHH fails to reach the machine address 00002183, because it stop the simulation too soon.

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No the issue is the you insist on remaining too stupid
to understand unreachable code.
>
void Infinite_Recursion()
{
   Infinite_Recursion();
   OutString("Can't possibly get here!");

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Olcott keeps dreaming of infinite recursions, even when HHH aborts after two cycles. Two is not infinite.
>

>
Yet in this same way Infinite_Recursion() itself
it not infinite when HHH aborts it in two cycles.
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What makes Infinite_Recursion() non-halting even
when it stops being emulated is that it cannot
possibly reach past its own first instruction.

>
That
>
  int main(void) {
>
    Infinite_Recursion();
    return 0;
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  }
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never returns makes Infinite_Recursion non-halting.
>

     void DDD()
    {
      HHH(DDD);
      return;
    }
     int main(void) {
      HHH(DDD);
      return 0;
    }
 The fact that DDD emulated by HHH never returns
makes DDD() non-halting.
 

Only by twisting the meaning of the term non-halting. The simulation does not reach the end, because it stopped the simulation too soon. Therefore, it prevents the program to halt. The early abort does not prove anything about the halting behaviour of the program described by the finite string. It only shows the failure of HHH to reach the end.
That this program has halting behaviour is proven by the semantics of the x86 language, which allows only one behaviour for the program described by this finite string. The direct execution, the simulation by the unmodified world class simulator and even by HHH1 show what this behaviour is: a halting program.
But HHH fails to reach the end of the simulation, because of a bug in its algorithm to detect an infinite recursion pattern. Therefore it produces false negatives, as proved in:
        int main() {
          return HHH(main);
        }
where HHH halts but decides that it does not halt.