systems, as a discrete version of the original continuous EPR-entangled systems. In
1964, John Bell [5] pointed out that for such spin-entangled systems, classical
hidden-variable theories would make different predictions from QM on measur e-
ments of correlated quantities. The theorem he published, later known as Bell’s
theorem, quantified just how strongly quantum particles were correlated than would
be classically allowed. This effectively opened up the possibility of experimentally
testing quantum mechanical predictions against those of classical hidden variable
theory. By now a number of experiments have been performed, and the results are
almost universally accepted to be fully in favor of QM [6–10]. However, from a
strictly logical point of ...