A Decidable Clock Language for Synchronous Specifications

AbstractPresence and absence of signals inside a reaction are inherent to the synchronous paradigm. Clocks are sets of instants (indicating for example when a signal is present) mainly used to describe the control part of data-flow specifications. The language C we define here expresses relations between clocks. Such relations can describe the combinational part of specifications, as well as particular instantaneous safety properties. We give a decision procedure for C and apply it to the model-checking of Signal programs abstracted from their state handling part. Thanks to the use of clocks, absence is not explicitly encoded by a special value