On 1/19/24 8:54 AM, olcott wrote:
> *This is the correct definition of a decider*
> Deciders always must compute the mapping from an input finite string to
> their own accept or reject state on the basis of a syntactic or semantic
> property of this finite string.
>
> *Definition of the HP based on the above definition of a decider*
> In computability theory, the halting problem is the problem of
> determining, whether an input finite string pair of program/input
> specifies a computation that would reach a final state and terminate
> normally.
>
> *Definition of halt decider based on the above definitions*
> (a) If simulating termination analyzer H correctly determines that D
> correctly simulated by H cannot possibly reach its own simulated final
> state and terminate normally then
>
Nope.
Where did you get the transition from
a input finite string pair of program/input specifies a computation that
would reach a final state and terminate normally
to
H correctly determines that D correctly simulated *by H* cannot possiby
reach its own simulated final state.
Note, the definition of a UTM say you can replace the actual running of
the machine representation with that of a UTM simulation (because it
will behave the same) but that operation also says such a simulation can
not abort, as the machine given as an input didn't stop running there.
THus adding the "by H" to your definition, you are REQUIRING that H can
not abort its simulation, and thus your statement (b) is meaningless, as
something that can not abort can not have conditions when it can abort.
You could say, if H correctly determines that (perhaps by its own
partial correct simulation) that an ACTUAL correct simulation of the
input by an actual UTM would not halt, you would be correct.
You H doesn't meet this requrement.
> (b) H can abort its simulation of D and correctly report that D
> specifies a non-halting sequence of configurations.
>
But only if H ACTUALLY DOES a correct simulation (which means never
aborts), and that simulation must be of the ACTUAL D, which in this case
used the H that aborts and returns the non-halting answer (not the OTHER
machine lyingly also called H which does a correct simulation).
So, you requirment boils down to a correct halting decider must not
abort its simulation, but also must abort its simulation.
Your H is just another name for the Barber that shaves everyone that
doesn't shave themselves, or the set of all sets that don't contain
themselves.
It just can not exist.
Your "proof" is based on the error or replacing the PROGRAM D, for a
tenplate that changes when the decider changes. Such a template is not a
program, so is a category error to give to a Halt Decider.
Yes, YOUR definition of D (which isn't of a program) make the Halting
Question about it invalid, because it isn't actually a program, which is
what the domain of the Halting Question is.