While classical Description Logics (DLs) concentrate on the representation of static conceptual knowledge, recently there is a growing interest in DLs that, additionally, allow to capture the temporal aspects of conceptual knowledge. Such temporal DLs are based either on time points or on time intervals as the temporal primitive. Whereas point-based temporal DLs are well-investigated, this is not the case for interval-based temporal DLs: all known logics either suffer from rather limited expressive power or have undecidable reasoning problems. In particular, there exists no decidable interval-based temporal DL that provides for general TBoxes—one of the most important expressive means in modern description logics. In this paper, for the first time we define an interval-temporal DL that is equipped with general TBoxes and for which reasoning is decidable (and, more precisely, ExpTime-complete).
Tree automata , Complexity , Temporal reasoning , Description logic