  Using the continuous-time random walk (CTRW) approach, we study the
phenomenon of relaxation of two-state systems whose elements evolve according
to a dichotomous process. Two characteristics of relaxation, the probability
density function of the waiting times difference and the relaxation law, are of
our particular interest. For systems characterized by Erlang distributions of
waiting times, we consider different regimes of relaxation and show that, under
certain conditions, the relaxation process can be non-monotonic. By studying
the asymptotic behavior of the relaxation process, we demonstrate that heavy
and superheavy tails of waiting time distributions correspond to slow and
superslow relaxation, respectively.
