In the case \(f=1\) the consistency condition \eqref{eqn16} is automatically satisfied because the projectors at \(t_1\) are orthogonal to each other, and the probabilities \(\inp{\Phi^\alpha}\) are those given by the usual Born rule. For \(f=2\) or more the consistency conditions are not trivial, and when they are satisfied \eqref{eqn17} provides a generalization of the Born rule.[1] Insight into the meaning of the consistency conditions is best obtained by working through examples;  see the   Further Reading supplement. Griffiths (2002a).--> Families for which the consistency conditions are satisfied are called consistent families, and it is only for this restricted class that the laws of quantum dynamics for a closed system can be used to assign a meaningful set of probabilities.