> From: space...@gmail.com
>
> On Wed, Sep 16, 2015 at 4:18 PM, Dave G4UGM <dave.g4...@gmail.com> wrote:
> > It is notable that in order to solve all problems, a computer must permit
> > self modifying code.
>
> From a theory of computation view, I don't believe that's true. Any
> computable function can be computed by a fixed program.
>
> For a particular computable function, there may be a more efficient
> implementation using self-modifying code.
>
> On the other hand, computing a particular computable function may
> require an arbitrariy amount of recursion, so it may take an
> arbitrarily amount of writable memory. The recusion may, of course,
> be implemented as some equivalent that doesn't require the computer to
> have explicit subroutine calls or stack, but the memory may still be
> required.
That may be true for computing but I'm not sure if it is practical
for real time control of complex systems.
Dwight
