XPost: comp.theory
On 10/12/2022 6:49 PM, Keith Thompson wrote:
olcott <polcott2@gmail.com> writes:
On 10/12/2022 5:37 PM, Richard Damon wrote:
On 10/12/22 11:08 AM, olcott wrote:
Professor Michael Sipser of MIT said that this verbatim paragraph
looks correct:
<quoted email to professor Sipser>
Here is what I would like to say:
Professor Michael Sipser of MIT said that this verbatim paragraph
looks correct:
If H does correctly determine that its correct simulation
of D would never stop running unless aborted, would it be
correct for H to abort this simulation and report that D
specifies a non-halting sequence of configurations?
This validates the idea of a simulating halt decider referenced in
this paper.
Rebutting the Sipser Halting Problem Proof
https://www.researchgate.net/publication/364302709_Rebutting_the_Sipser_Halting_Problem_Proof
Professor Sipser has not had the time to carefully review this paper
presented to him.
</quoted email to professor Sipser>
<quoted reply from professor Sipser>
Looks ok. Thanks for checking.
</quoted reply from professor Sipser>
IF I drop by and ask him face to face, will he confirm this?
Yes.
Would Professor Sipser agree that you have refuted his halting problem
proof?
If I understand this correctly, it does not support the idea that a
general "simulating halt decider" can actually exist.
In the above, let D be a program that may or may not halt, and let H be
an observer who attempts to determine whether or not D halts.
Concretely, let D be this C program or equivalent:
int main(void) { while (1) { } }
and I'll be H. I can observe D. I can simulate it until I get bored,
which won't take long (one iteration, two iterations, three iterations, zzzzzzzzz). I can, while simulating it, conclude that it will never
halt, abort the simulation, and report that it never halts. It wouldn't
be difficult to automate the process in a way that works for this simple case.
My scope is to prove that the "impossible"
input to all the halting problem proofs <is>
decidable. Refuting the halting problem itself
has never been in scope.
int DD()
{
int Halt_Status = HHH(DD);
if (Halt_Status)
HERE: goto HERE;
return Halt_Status;
}
HHH(DD) does correctly determine that its input DD
would never stop running unless aborted.
--
Copyright 2024 Olcott
"Talent hits a target no one else can hit;
Genius hits a target no one else can see."
Arthur Schopenhauer
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