In <6htajh$rq2 at ux.cs.niu.edu>, rickert at cs.niu.edu (Neil Rickert) writes:
[snip]
>You seem to have entirely missed a point I made. Namely, there might
>be a completely different way of describing the internal operations
>of a computer, such that under this different internal description the
>computer is executing a completely different algorithm. If it is
>the abstract computation that matters, then I am suggesting that the
>abstract computation being performed is not determined by what happens
>in the machine, in the sense that there are completely different
>ways of assigning algorithmic descriptions to what happens physically.
Let's focus on this point very closely.
Consider a very simple computer. It's called an "OR gate". It has
two external inputs, and one external output.
The function it computes is "logical OR". If either of the inputs is
active, the output is active. If both inputs are inactive, the output
is inactive.
I say that the function it computes is determined by whatever is inside
the black box of the computer, and will remain the same no matter how
you choose to describe it. The function will remain the same even if
can find no use for it, or if you think it is computing NOT(NOT A AND
NOT B). It does what it does, regardless.
If you agree, then I'll add more inputs, and complicate the function a
little. I'll claim that nothing has changed, that the function being
computed is still dependent on what is inside the box, not on your
description. I'll claim that this holds regardless of how complex we
make that internally-computed function.
What do you say?
Bill