 If we assume that players’ beliefs are always consistent with this equality, then we may define a sequential equilibrium. A SE has two parts: (1) a strategy profile § for each player, as before, and (2) a system of beliefs μ for each player. μ assigns to each information set h a probability distribution over the nodes in h, with the interpretation that these are the beliefs of player i(h) about where in his information set he is, given that information set h has been reached. Then a sequential equilibrium is a profile of strategies § and a system of beliefs μ consistent with Bayes’s rule such that starting from every information set h in the tree player i(h) plays optimally from then on, given that what he believes to have transpired previously is given by μ(h) and what will transpire at subsequent moves is given by §.