Towards a Modal Logic of Durative Actions

This paper proposes an extension of modal action logics, which typically make the assumption that an action is atomic, to include durative actions. These logics have been developed to support the formal specification of information systems: we argue, with particular reference to object oriented systems, that assuming atomicity is too restrictive to express many kinds of temporal constraint. In consequence, we propose that actions be regarded as durative, and encode this by assuming that an action occurs over a sequence of atomic transitions, or interval, rather than a single transition. With this as a pre-requisite, the paper continues to redefine and extend operators of atomic action logics to fit the durative case.