Sujet : Re: Final Statement on the Halting Problem
De : mikko.levanto (at) *nospam* iki.fi (Mikko)
Groupes : comp.theoryDate : 17. Jun 2025, 09:27:05
Autres entêtes
Organisation : -
Message-ID : <102r8sp$293fk$1@dont-email.me>
References : 1 2 3 4 5
User-Agent : Unison/2.2
On 2025-06-16 18:33:59 +0000, Mr Flibble said:
On Mon, 16 Jun 2025 13:11:23 +0300, Mikko wrote:
On 2025-06-15 19:21:09 +0000, Mr Flibble said:
On Sun, 15 Jun 2025 14:23:36 -0400, Richard Damon wrote:
On 6/15/25 9:55 AM, Mr Flibble wrote:
The halting problem as defined ignores recursive self reference
focusing on the paradox instead, I would argue the recursive self
reference leads to infinite regress in the definition of the problem
thus creating a category error making the problem definition itself
ill-formed.
/Flibble
But there is no recursive self-reference in the halting problem.
You only get that recursion when you assume that there exists a
program that can solve it, which is what shows that there is not
computation that can solve the halting problem.
You have just fallen for Peter Olcotts deceptive strawman definition
of the halting problem, because you don't really understand what you
are talking about.
Damon's response is defensive, dismissive, and slightly aggressive in
tone. But setting tone aside for a moment, let's analyze the *technical
content* of his reply point by point.
---
### 🔍 **Claim-by-Claim Analysis**
#### **1. "But there is no recursive self-reference in the halting
problem."**
This is partially true, depending on what one means by "the halting
problem."
Unless otherwise specified, one means the halting problem of Turing
machines.
* The *general formulation* of the halting problem does **not** involve
self-reference:
“Given a program $P$ and input $x$, determine whether $P(x)$
halts.”
The halting problem is to construct a Turing machine that can answer
every question of the above pattern.
That’s just a predicate over two arguments—no recursion or
self-reference is involved here *yet*.
* However, **self-reference is absolutely introduced** in the *proof of
undecidability*, specifically in Turing's diagonal argument using $H(P,
P)
$ and the construction of a paradoxical program $D$ such that $D(D)$
leads to contradiction.
There is no self-reference in Turing's construction of $D$. If $H$ is
any Turing machine it is possible to construct the corresponding $D$.
Then one can run $D(D)$ and see whether it halts or enters a loop that
can easily be seen as non-halting. Turing's $D$ does not do anything
else. If is also possible to run $H(D, D)$ and then compare its answer
to the observed behaviour of $D(D)$. There is nothing paradoxcal there,
the answer is simply wrong.
BULLSHIT
That term is not applicable to my words, as they clearly are meaningful,
relevant, and true.
-- Mikko