Sujet : Re: DDD specifies recursive emulation to HHH and halting to HHH1
De : F.Zwarts (at) *nospam* HetNet.nl (Fred. Zwarts)
Groupes : comp.theoryDate : 27. Mar 2025, 20:56:40
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vs4aho$101mm$2@dont-email.me>
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Op 27.mrt.2025 om 18:50 schreef olcott:
On 3/27/2025 2:18 AM, Fred. Zwarts wrote:
Op 27.mrt.2025 om 04:09 schreef olcott:
On 3/26/2025 8:22 PM, Richard Damon wrote:
>
_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]
>
Non-Halting is that the machine won't reach its final staste even if an unbounded number of steps are emulated. Since HHH doesn't do that, it isn't showing non-halting.
>
>
DDD emulated by any HHH will never reach its final state
in an unbounded number of steps.
>
DDD emulated by HHH1 reaches its final state in a finite
number of steps.
>
It is not very interesting to know whether a simulator reports that it is unable to reach the end of the simulation of a program that halts in direct execution.
That IS NOT what HHH is reporting.
HHH correctly rejects DDD because DDD correctly
emulated by HHH cannot possibly reach its own
final halt state.
Yes, that is the same in other words as rejecting because it could not correctly simulate the input up to its end. An end that exists as proven by direct execution and world-class simulators.
It is not very interesting to know whether a simulator reports that it is unable to reach the end of the simulation of a program that halts in direct execution (and therefore rejects the input).
It is interesting to know:
'Is there an algorithm that can determine for all possible inputs whether the input specifies a program that (according to the semantics of the machine language) halts when directly executed?'
This question seems undecidable for Olcott.
It is interesting to know:
'Is there an algorithm that can determine for all possible inputs whether the input specifies a program that (according to the semantics of the machine language) halts when directly executed?'
It is the halts while directly executed that is impossible
for all inputs. No TM can ever report on the behavior of
the direct execution of any other TM.
I assume that is a 'no' to the question. Correct?
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