Correct OO systems in computational logic

Object Oriented Design Frameworks (OOD frameworks) are groups of interacting objects. We have formalised them in computational logic as open systems of interacting objects. Our formalisation is based on steadfast logic programs in the context of open specification frameworks. However, we have considered only the static aspects, namely the specification of constraints and the correctness of queries (programs that do not update the current state). In this paper we extend this static model, by introducing actions that update the current state.