Peter Olcott says...
Quick Summary:
Alan Turing conclusively proved is that it is impossible to construct a halt
analyzer that always returns a correct result back to the program being
analyzed.
Since returning the result back to the program being analyzed is not the only
way to construct a halt analyzer, his proof did not show that constructing a
halt analyzer that works correctly for all input is impossible.
Turing *defined* what he meant by a "solution to the halting problem"
and by that definition, there *is* no solution. You are proposing a
*different* definition. Turing's proof does not *directly* apply to
your new definition. You haven't refuted Turing, you've changed the
subject.
Now, if you want to introduce a broader notion of what it means to
"solve the halting problem", you are free to do so. If you could somehow
show that it is solvable in this broader sense, you *wouldn't* have
refuted Turing, because Turing was talking about a *different* sense
of "solvable". So even if you were right, your arguments wouldn't
constitute a refutation of Turing.
As to the question of whether the halting problem is solvable in a
broader sense, that's where Church's thesis comes in. Church conjectured
(he didn't prove, because there is no way to rigorously prove a claim
that involves the intuitive meanings of words) that any problem that
is computable in a broader sense of "computable" is computable by
Turing machines (or in the lambda calculus, or in Godel's theory of
partial recursive functions, etc.)
So, if you managed to solve the halting problem in a way that could
*not* be translated into Turing's notion of solvable, then you would
be disproving Church's thesis, not Turing's proof of the unsolvability
of the halting problem.
Of course, you haven't given anything whatsoever that shows any
hope of solving the halting problem. What you've been concentrating
on is trying to defeat the *proof* that a program doesn't solve
the halting problem. That is a completely nonsensical approach.
It's as if I claim that there are no pink elephants. You note that to
demonstrate that an elephant is not pink, I must turn on the
light. So your approach to producing a pink elephant is to build a dark
building with no lights, and to confiscate any candles or
flashlights that anyone takes into the building. That way, nobody
can prove that you don't have a pink elephant.
The way to prove that a program is not a solution to the halting
problem is to run it on some tough cases, in some special circumstances.
If you somehow arrange things so that your program refuses to answer
in a circumstance in which its answer could be used against it, then
you have defeated the proof that it is not a solution to the halting
problem. But that doesn't mean that you have solved the halting problem,
any more than having an elephant in a dark room is a proof that you
have a pink elephant.
You're using the tricks of a professional psychic --- if someone attempts
to actually *test* whether the psychic has psychic abilities, the psychic
claims that "Oh, my abilities don't work in the presence of cynics and
doubters". If that's the psychic's claim, then there is, indeed, no
way to prove that the psychic is a fraud. But you would strongly suspect
it.
Peter, you are a fraud of the exact same kind.