  When mixed states are composed of s memory patterns, s types of mixed states,
which can become equilibrium states of the model, can be generated. We
previously reported that storage capacities for most mixed states composed of
uncorrelated memory patterns do not diverge at the sparse limit of the firing
rate, f -> 0. On the contrary to the uncorrelated case, we show that the
storage capacities for all mixed states composed of correlated memory patterns
diverge as 1/|f log f| even when the correlation of memory patterns is
infinitestimal small. We also show that, when the firing rate is fixed, as the
correlation coefficient increases, the storage capacities of the mixed states
composed of all correlated memory patterns increase, while those of the mixed
states composed of only some of the correlated memory patterns decrease.
