Earlier quoted context omitted.
Whatever free will is, this can't be the definition of it. Consider two computers, build for one and only one purpose: to compute the first 10 digits of pi. They do this without any external input. But one computer is made of vacuum tubes, one made of transistors, both of which computed the first 10 digits of pi. They both took the same action (computing the first 10 digits of pi) and it was independent of how they w…
They're both computing pi due to how they are constructed. If they were built to compute e and computed pi instead they would have free will. You're misreading my description.
You first have to show that it is impossible to construct something in a way that it has free will. To show that, however, I think you'd need a definition of "free will" which is not "doing something it wasn't constructed to do" on pain of either circularity or contradiction.