 We make the assumption, which remains tacit in most expositions, that we have an appropriate choice of subsets of \(\Lambda\) to be regarded as the measurable subsets, forming a measurable space to which probabilistic considerations may be applied. It is assumed that the mode of generation of the pairs establishes a probability distribution \(\rho\) that is independent of the adventures of each of the two systems after they separate. This does not preclude temporal evolution of the properties of the two systems after separation. What is assumed is that the state \(\lambda\) prescribes probabilities for subsequent events (including any temporal evolution), and thereby probabilities for outcomes of experiments to be performed on the systems.