Re: Can D simulated by H terminate normally?

On 4/30/2024 11:46 AM, Alan Mackenzie wrote:

olcott <polcott333@gmail.com> wrote:

On 4/30/2024 10:44 AM, Alan Mackenzie wrote:

olcott <polcott333@gmail.com> wrote:

On 4/30/2024 3:46 AM, Fred. Zwarts wrote:

Op 29.apr.2024 om 21:04 schreef olcott:

 

[ .... ]

 

The ONLY way that we can determine if any computation is correct is
when it meets its specification. When a TM is specified to calculate
the sum of a pair of decimal integers and it derives any decimal
integer other than 5 from inputs 2,3 then it is incorrect.

 

Changing the subject. The question is not whether it is correct, but
whether it halts. Incorrect programs exist and even those program may
halt.

 

I had to address this:

 

On 4/29/2024 11:17 AM, Alan Mackenzie wrote:

There is no notion of "correct" in a turing machine.  It is either
running, or has reached a final state.  In the TM equivalent of "core
dump", a final state has most definitely been reached.

 

I would indeed be charmed if you would address it, but you have evaded
it, as you have evaded most of the points I made yesterday.

 

Note that I said there is no correctness _IN_ a turing machine.  This is
independent of whether or not that turing machine is useful for some
external purpose.

 

Note also that you wilfully distorted my meaning by trimming.  The full
context was:

 

Core dump abnormal termination does not count as the program
correctly finished its processing.

 

There is no notion of "correct" in a turing machine.  It is either
running, or has reached a final state.  In the TM equivalent of "core
dump", a final state has most definitely been reached.

 

Your use of the word "correctly" in "correctly finished its processing"
is wrong.  A turing machine is either running or it's finished its
processing.  From the point of view of the tm, there is no "correct" or
"incorrect" associated with the latter condition; it's simply reached a
final state.

 

You are thus mistaken in believing "abnormal" termination isn't a final
state.

 Again, we have no reply from you to this important point.  You've failed
to address any of the points I made, presumably because you can't.
 

When we add the brand new idea of {simulating termination analyzer}
....

 It is most unlikely to be "brand new", and even if it were, it would most
likely be useless and inconsequential.  But since you fail to define it,
we can only judge it by the reputation of its creator.
 

.... to the existing idea of TM's then we must be careful how we define
halting otherwise every infinite loop will be construed as halting.

 Complete Balderdash.  Define your "simulating termination analyzer", or
stop wasting people's time by talking about it.
 

int H(ptr x, ptr y); // ptr is pointer to int function
01 int D(ptr x)
02 {
03   int Halt_Status = H(x, x);
04   if (Halt_Status)
05     HERE: goto HERE;
06   return Halt_Status;
07 }
08
09 void main()
10 {
11   H(D,D);
12 }
(a) It is a verified fact that D(D) simulated by H cannot
possibly reach past line 03 of D(D) simulated by H whether H
aborts its simulation or not.
Before we can get into the computer science of a simulating
termination analyzer we must first have mutual agreement on
the software engineering of it.
ONLY when we mutually agree on the (a) point can we proceed to
the next point. If we don't do it this way then everyone simply
leaps to the conclusion that I must be wrong without ever fully
understanding what I am saying.
--
Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius
hits a target no one else can see." Arthur Schopenhauer