Re: DD simulated by HHH cannot possibly halt (Halting Problem)

On 4/5/2025 11:59 AM, olcott wrote:

On 4/5/2025 2:42 AM, Richard Heathfield wrote:

On 05/04/2025 07:14, olcott wrote:

On 4/4/2025 10:49 PM, Richard Heathfield wrote:

On 05/04/2025 00:41, olcott wrote:

*Simulating termination analyzer Principle*
It is always correct for any simulating termination
analyzer to stop simulating and reject any input that
would otherwise prevent its own termination. The
only rebuttal to this is rejecting the notion that
deciders must always halt.

>

>
typedef void (*ptr)();
int HHH(ptr P);
>
int DD()
{
   int Halt_Status = HHH(DD);
   if (Halt_Status)
     HERE: goto HERE;
   return Halt_Status;
}
>
int main()
{
   HHH(DD);
}
>

In other words, you operate on the principle that deciders don't have to (and indeed can't) always make a correct decision on whether an input program halts.
>

>
The termination analyzer HHH would be correct
to determine that it must stop simulating DD to
prevent its own non-termination

>
Fine, but then it fails to do its job. What you are learning (albeit slowly) is that the termination analyser HHH can't analyse whether DD terminates. It is therefore not a general purpose termination analyser.
>

 Introduction to the Theory of Computation 3rd Edition
by Michael Sipser (Author) (best selling textbook)
 <MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>
     If simulating halt decider H correctly simulates its input D
     until H correctly determines that its simulated D would never
     stop running unless aborted then
      H can abort its simulation of D and correctly report that D
     specifies a non-halting sequence of configurations.
</MIT Professor Sipser agreed to ONLY these verbatim words 10/13/2022>

But not what you think he agreed to:
On Monday, March 6, 2023 at 2:41:27 PM UTC-5, Ben Bacarisse wrote:
 > Fritz Feldhase <franz.fri...@gmail.com> writes:
 >
 > > On Monday, March 6, 2023 at 3:56:52 AM UTC+1, olcott wrote:
 > >> On 3/5/2023 8:33 PM, Fritz Feldhase wrote:
 > >> > On Monday, March 6, 2023 at 3:30:38 AM UTC+1, olcott wrote:
 > >> > >
 > >> > > I needed Sipser for people [bla]
 > >> > >
 > >> > Does Sipser support your view/claim that you have refuted the halting theorem?
 > >> >
 > >> > Does he write/teach that the halting theorem is invalid?
 > >> >
 > >> > Tell us, oh genius!
 > >> >
 > >> Professor Sipser only agreed that [...]
 > >
 > > So the answer is no. Noted.
 > >
 > >> Because he has >250 students he did not have time to examine anything
 > >> else. [...]
 > >
 > > Oh, a CS professor does not have the time to check a refutation of the
 > > halting theorem. *lol*
 > I exchanged emails with him about this. He does not agree with anything
 > substantive that PO has written. I won't quote him, as I don't have
 > permission, but he was, let's say... forthright, in his reply to me.
 >
On 8/23/2024 5:07 PM, Ben Bacarisse wrote:
 > joes <noreply@example.org> writes:
 >
 >> Am Wed, 21 Aug 2024 20:55:52 -0500 schrieb olcott:
 >
 >>> Professor Sipser clearly agreed that an H that does a finite simulation
 >>> of D is to predict the behavior of an unlimited simulation of D.
 >>
 >> If the simulator *itself* would not abort. The H called by D is,
 >> by construction, the same and *does* abort.
 >
 > We don't really know what context Sipser was given.  I got in touch at
 > the time so do I know he had enough context to know that PO's ideas were
 > "wacky" and that had agreed to what he considered a "minor remark".
 >
 > Since PO considers his words finely crafted and key to his so-called
 > work I think it's clear that Sipser did not take the "minor remark" he
 > agreed to to mean what PO takes it to mean!  My own take if that he
 > (Sipser) read it as a general remark about how to determine some cases,
 > i.e. that D names an input that H can partially simulate to determine
 > it's halting or otherwise.  We all know or could construct some such
 > cases.
 >
 > I suspect he was tricked because PO used H and D as the names without
 > making it clear that D was constructed from H in the usual way (Sipser
 > uses H and D in at least one of his proofs).  Of course, he is clued in
 > enough know that, if D is indeed constructed from H like that, the
 > "minor remark" becomes true by being a hypothetical: if the moon is made
 > of cheese, the Martians can look forward to a fine fondue.  But,
 > personally, I think the professor is more straight talking than that,
 > and he simply took as a method that can work for some inputs.  That's
 > the only way is could be seen as a "minor remark" with being accused of
 > being disingenuous.
On 8/23/2024 9:10 PM, Mike Terry wrote:
 > So that PO will have no cause to quote me as supporting his case:  what
 > Sipser understood he was agreeing to was NOT what PO interprets it as
 > meaning.  Sipser would not agree that the conclusion applies in PO's
 > HHH(DDD) scenario, where DDD halts.