Abstract
We combine the modal logic S5 with the description logic (DL) ALCQI. In this way, we obtain a multi-dimensional DL, S5ALCQI, whose purpose is reasoning about change. S5ALCQI is capable of expressing that concepts and roles change over time, but cannot discriminate between changes in the past and in the future. Our main technical result is that S5ALCQI concept satisfiability with respect to terminologies of general concepts inclusions (GCIs) is decidable and 2-ExpTime-hard. We also provide a scenario based on temporal conceptual models with timestamping constraints in which the logic can be used.