  In an earlier paper we introduced a notion of Markov automaton, together with
parallel operations which permit the compositional description of Markov
processes. We illustrated by showing how to describe a system of n dining
philosophers, and we observed that Perron-Frobenius theory yields a proof that
the probability of reaching deadlock tends to one as the number of steps goes
to infinity. In this paper we add sequential operations to the algebra (and the
necessary structure to support them). The extra operations permit the
description of hierarchical systems, and ones with evolving geometry.
