  Steve Gull, in unpublished work available on his Cambridge University
homepage, has outlined a proof of Bell's theorem using Fourier theory. Gull's
philosophy is that Bell's theorem (or perhaps a key lemma in its proof) can be
seen as a no-go theorem for a project in distributed computing with classical,
not quantum, computers. We present his argument, correcting misprints and
filling gaps. In his argument, there were two completely separated computers in
the network. We need three in order to fill all the gaps in his proof: a third
computer supplies a stream of random numbers to the two computers representing
the two measurement stations in Bell's work. One could also imagine that
computer replaced by a cloned, virtual computer, generating the same
pseudo-random numbers within each of Alice and Bob's computers. Either way, we
need an assumption of the presence of shared i.i.d. randomness in the form of a
synchronised sequence of realisations of i.i.d. hidden variables underlying the
otherwise deterministic physics of the sequence of trials. Gull's proof then
just needs a third step: rewriting an expectation as the expectation of a
conditional expectation given the hidden variables.
