Re: Analysis of Flibble’s Latest: Detecting vs. Simulating Infinite Recursion ZFC

On 24/05/2025 22:40, Keith Thompson wrote:

Mike Terry <news.dead.person.stones@darjeeling.plus.com> writes:

On 24/05/2025 01:36, Keith Thompson wrote:

Ben Bacarisse <ben@bsb.me.uk> writes:

Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

Ben Bacarisse <ben@bsb.me.uk> writes:
[...]

And the big picture is that this can be done because false is the
correct halting decision for some halting computations.  He has said
this explicitly (as I have posted before) but he has also explained it
in words:
>
| When-so-ever a halt decider correctly determines that its input would
| never halt unless forced to halt by this halt decider this halt
| decider has made a correct not-halting determination.

>
Hmm.  I don't read that the way you do.  Did I miss something?
>
It assumes that the input is a non-halting computation ("its input
would never halt") and asserts that, in certain circumstances,
his mythical halt decider correctly determines that the input
is non-halting.
>
When his mythical halt decider correctly determines that its input
doesn't halt, it has made a correct non-halting determination.
It's just a tautology.

>
It would be a tautology but for the "unless..." part.  It does not make
the determination that it does not halt.  It determines that it would
not halt were it not for the fact that the decider (a simulation) in
fact halts it.

Right, so the computation itself is non-halting.

>
No no no, it halts!

 What halts?
 

                      (Assuming we're discussing the computation DD() with PO's code.)

 No, I'm not going to assume that.  *All* I'm talking about is olcott's
statement:
 

| When-so-ever a halt decider correctly determines that its input would
| never halt unless forced to halt by this halt decider this halt
| decider has made a correct not-halting determination.

 I'm not trying to make it consistent with anything else olcott has
written.  DD() is irrelevant to what I'm talking about.
 As I wrote before, let H be the "halt decider" and let I be its input
(which represents a computation).  I by itself does not halt.
I-simulated-by-H may halt if H forces it to halt.
 H might be a simulator, or it may just monitor the execution of I with
the ability to halt it.  H is not a pure simulator; it does not always
fully simulate the execution of I.
 H is given the task of determining whether I is a halting computation or
not (a task that is not possible in all cases, but is certainly possible
in some cases).

Fair enough.
Your interpretation of Olcott's statement is indeed a tautology.  That tautology is not very interesting, and most people would interpret the statement in the same as you (and me).
PO's interpretation of the statement is wrong, but that doesn't interest you - he said the words and the words are correct in some absolute sense even if PO does not understand that sense, and is thinking of something different.  PO made a true statement!
Interestingly, you're doing what PO does, sort of - he says the words mean what /he/ says they mean, and that meaning justifies one of his false claims.  He supports this claim by saying Sipser agreed with the words, even though it's clear Sipser's agreement was with a different interpretation of those words.
<PO speaking>
But hey, Sipser "agreed with those words"!  Sipser just didn't appreciate the consequence of their true meaning [aka PO's interpretation].  :)
</PO speaking>
[...]

 

So sure, you can say the statement is a tautology, but PO made that
statement and his interpretation of what it means is far from your
tautology.

 Sure, he does that.
 My overall point, I suppose, is that if people are going to argue with
olcott, if he happens to make a true statement it's not helpful to argue
that its false.

I'm all for that - I'd go further to say that I champion that point of view.  But if PO makes a statement which he intends to mean XXX and XXX is false, has he made a true statement just because your interpretation of the same statement is YYY, different from XXX, and YYY happens to be true?
In any case, I don't think anyone would disagree with your interpretation of the statement being a tautology...  Certainly not me.  (I think that's all that's to be said on this.)
Mike.