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On 7/26/2024 3:50 AM, joes wrote:But you have been told that it is not enough to simulate only four instructions of a halting program. The simulation is aborted when the simulated HHH has only one cycle to go. This makes the simulation incomplete and incorrect, because it does not show the full behaviour of DDD/HHH.Am Thu, 25 Jul 2024 23:25:59 -0500 schrieb olcott:That does not matter. As long as we understand that Mike is correct about this:On 7/25/2024 10:35 PM, Mike Terry wrote:>On 26/07/2024 01:53, olcott wrote:On 7/25/2024 4:03 PM, Mike Terry wrote:On 25/07/2024 14:56, olcott wrote:On 7/24/2024 10:29 PM, Mike Terry wrote:On 23/07/2024 14:31, olcott wrote:On 7/23/2024 1:32 AM, 0 wrote:On 2024-07-22 13:46:21 +0000, olcott said:On 7/22/2024 2:57 AM, Mikko wrote:On 2024-07-21 13:34:40 +0000, olcott said:On 7/21/2024 4:34 AM, Mikko wrote:On 2024-07-20 13:11:03 +0000, olcott said:On 7/20/2024 3:21 AM, Mikko wrote:On 2024-07-19 14:08:24 +0000, olcott said:>(b) We know that a decider is not allowed to report on theNo, we don't. There is no such prohibition.
behavior computation that itself is contained within.>Therefore It is not allowed to report on its own behavior.Anyway, that does not follow. The theory of Turing machines does
not prohibit anything.I don't see how the outside use of a function can influence it.In this case we have two x86utm machines that are identical except
that DDD calls HHH and DDD does not call HHH1.
>Thanks, Mike, for the detailed analysis.OK great, we are making headway.It is empirically proven according to the semantics of the x86Perhaps your actual code does behave differently!
machine code of DDD that DDD correctly emulated by HHH has different
behavior than DDD correctly emulated by HHH1.
>How is the trace passed?The questions are:>
a) are HHH and HHH1 "identical copies", in the TM machine sense of
incorporating
the algorithm of one TM inside another TM? (As Linz
incorporates H inside H^, meaning that the behaviours of H
and embedded_H MUST be identical for any input.)
[You claim HHH and HHH1 /are/ proper copies, and yet give
different results for input (D), which is impossible.]
They are identical in the that have identical x86 machine code except
for the x86 quirk that function calls are to a relative rather than
absolute address. So when HHH calls the same function that HHH1 calls
the machine code is not the same. The only other case where the
machine code of HHH1 and HHH is not identical is the way for slave
instances of HHH to pass its execution trace up to the master.
>
Message-ID: <rLmcnQQ3-N_tvH_4nZ2dnZfqnPGdnZ2d@brightview.co.uk>
On 3/1/2024 12:41 PM, Mike Terry wrote:
>
> Obviously a simulator has access to the internal state
> (tape contents etc.) of the simulated machine. No problem there.
Then we know that HHH can see the the first four instructions of
DDD have no conditional code that could prevent them from endlessly
repeating.
This is the exact same pattern with Infinite_Recursion()
where there are no conditional branch instructions that
would prevent the first three instructions of
Infinite_Recursion() from endlessly repeating.
_Infinite_Recursion()
[0000215a] 55 push ebp
[0000215b] 8bec mov ebp,esp
[0000215d] e8f8ffffff call 0000215a ; recursive call
[00002162] 5d pop ebp
[00002163] c3 ret
Size in bytes:(0010) [00002163]
Begin Local Halt Decider Simulation Execution Trace Stored at:113934
Decide_Halting_HH:1
[0000215a][00113924][00113928] 55 push ebp
[0000215b][00113924][00113928] 8bec mov ebp,esp
[0000215d][00113920][00002162] e8f8ffffff call 0000215a
[0000215a][0011391c][00113924] 55 push ebp
[0000215b][0011391c][00113924] 8bec mov ebp,esp
[0000215d][00113918][00002162] e8f8ffffff call 0000215a
Local Halt Decider: Infinite Recursion Detected Simulation Stopped
The relative addressing is to be expected as a difference, and is fineThere never is any actual bug with the simulation.
provided the actual target is the same. [Which it seems to be...]
The whole thing with the slave instances might well be where the bug
lies! That would be slightly funny, as I pointed out that problem on
some completely unrelated post, and this could be a follow-on issue
where it has caused observable misbehavior in the code. (Needs a bit
more investigation...)
>I bet my nonexistent soul that there are bugs left in libx86. ApartThat is irrelevant. We can see by the execution trace of
from that, your use of the library may be buggy.
>
DDD emulated by HHH that this emulation does precisely
match the semantics of the first four x86 machine language
instructions of DDD.
We can also see that DDD emulated by HHH1 does precisely
match the semantics of the x86 machine language instructions
of DDD.
People have been saying that I am wrong about the for three
years never bothering to notice that I have always proved
that I am correct about this.
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