Clock Di erence
نویسندگان
چکیده
In this paper, we present Clock Diierence Diagrams, a new BDD-like data-structure for eeective representation and manipulation of certain non-convex subsets of the Euclidean space, notably those encountered in veriication of timed automata. It is shown that all set-theoretic operations including inclusion checking may be carried out eeciently on Clock Diierence Diagrams. Other central operations needed for analysing timed automata (e.g. future-and reset-operations), are readily deened using an eeectively obtained, relative normal form. A version of the real-time veriication tool Uppaal using Clock Diier-ence Diagrams as the main data-structure has been implemented. Experimental results demonstrate signiicant space-savings: between 46% and 99% for a number of industrial examples.
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