bell formalized the idea of a hidden variable by introducing the parameter formula_20 to locally characterize measurement results on each system: "it is a matter of indifference ... whether λ denotes a single variable or a set ... and whether the variables are discrete or continuous". however, it is equivalent (and more intuitive) to think of formula_20 as a local "strategy" or "message" that occurs with some probability formula_22 when alice and bob reboot their experimental setup. epr's criteria of local separability then stipulates that each local strategy defines the distributions of independent outcomes if alice conducts experiment x and bob conducts experiment formula_23: