Re: Michael Sipser of MIT validates the notion of a simulating halt decider

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