We extend a conventional action system with a primitive action
consisting of a differential equation and an evolution invariant.
The semantics is given by a predicate transformer. The weakest
liberal precondition is chosen, because it is not always desirable
that steps corresponding to differential actions shall terminate.
It is shown that the proposed differential action has a semantics
which corresponds to a discrete approximation when the discrete
step size goes to zero. The extension gives action systems the
power to model real-time clocks and continuous evolutions within
|Number of pages||20|
|Publication status||Published - 1997|