Invisible wrote:
> I implicitly assumed that any machine that can't process it's own 
> program isn't worthy of the title "computer", that's all. ;-) But yes, I 
> see what you're saying.

So, your brain is weaker than a Turing machine? Cool.

It's the simplicity of the machines that make them amenable to 
universality, not the complexity. Remember that the Von Neumann 
architecture was a breakthrough.

> As for being able to perform infinite instructions in finite time... 
> surely that just makes it even *harder* to predict what the machine will 
> od, no?

Not if it can process its own input. Think about how the halting problem 
works, and why... If the machine has unbounded state, it might run 
forever without ever getting into the same state twice. But if you can 
run the computer forever without it actually taking forever, then you 
can say definitively "no, that machine never stops."

And a machine that can run an infinite number of instructions in finite 
time *always* stops. ;-)

-- 
Darren New / San Diego, CA, USA (PST)

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