“…A main objection to the use of duration calculus, which is geared to state-based description of systems, is that it does not match most languages related to programming real-time reactive systems, which are geared to event-based description, nicely. In this connection, it is interesting to see that it is not entirely clear how the definitions of the semantics of SL and PL presented in [32] relate to the earlier definitions, presented in [31] and [16,25], which they replace. A main purpose of this paper is to make it generally easier to establish semantic links between duration calculus and formalisms aimed at programming.…”