In this paper, the formalism of Relational Transition Systems (RTSes)
is used to model data-intensive reactive systems, and four RTS models
of reactive systems based on temporal logic programming, production sy
stems, recurrence equations, and Petri nets are presented. The paper a
lso describes different methods of comparison of the expressive powers
of various RTSes in terms of the trajectories they can generate and c
arries out this comparison for the four RTS formalisms. It is shown th
at these formalisms have the same expressive power in the deterministi
c case. The paper also compares expressive powers of non-deterministic
production systems and non-deterministic temporal logic programming s
ystems. It is shown that, although the two formalisms are incomparable
in the general case, their restricted versions are isomorphic to each
other.