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Logics & Preorders from logic to preorder – and back Kim Guldstrand Larsen Paul Pettersson Mogens Nielsen BRICS@Aalborg BRICS@Aarhus. Timed Logics. Real-time temporal logic (RTTL, Ostroff and Wonham 85) Metric Temporal Logic (Koymans, 1990)
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Logics & Preordersfrom logic to preorder – and backKim Guldstrand Larsen Paul Pettersson Mogens Nielsen BRICS@AalborgBRICS@Aarhus
Timed Logics ..... • Real-time temporal logic (RTTL, Ostroff and Wonham 85) • Metric Temporal Logic (Koymans, 1990) • Explicit Clock Temporal Logic (Harel, Lichtenstein, Pnueli, 1990) • Timed Propositional Logic (Alur, Henzinger, 1991) • Timed Computational Tree Logic (Alur, Dill, 1989) • Timed Modal Mu-Calculus(Larsen, Laroussinie, Weise, 1995) • Duration Calculus (Chaochen, Hoare, Ravn, 1991)
Timed Modal Logic Kozen’83 Atomic Prop Action Modalities Boolean Connectives Recursion Variables
Timed Modal Logic Larsen, Holmer, Wang’91 Larsen, Laroussine, Weise, 1995 Larsen, Pettersson, Wang, 1995 Delay Modalities Atomic Prop Action Modalities Boolean Connectives Formula Clock Constr Recursion Variables Formula Clock Reset
Semantics formula state of timed automata timed asgn for formula clocks Semantics
Derived Operators f holds between l and u Invariantly Timed Modal Mu-calculus is at least as expressive as TCTL Weak UNTIL Bounded UNTIL
Symbolic Semantics formula location region over C and K Region-based Semantics THEOREM
Fundamental Results Decidable EXPTIME-complete (Aceto,Laroussinie’99) Given f and automaton A does A satisfy f ? Given f does there exist an automaton A satisfying f ? UNDECIDABLE (strong conjecture) Given f and given clock-set C and max constant M. Does there exist an automaton A over C and M satisfying f ? Decidable
Timed Bimulation Wang’91, Cerans’92
Timed Bisimulation Wang’91
Towards Timed Bisimulation Algorithm Cerans’92 independent “product-construction”
Towards Timed Bisimulation Algorithm Definition Theorem
Timed Bisimulation Algorithm = Checking for TB-ness using Regions y 2 1 1 x AX,R0 AY,R3 AX,R1 a1 a2 AX,R2
Characteristic Propertyfor finite state automata Larsen, Ingolfsdottir, Sifakis, 1987 Ingolfsdottir, Steffen, 1994 a1 m1 n mk ak
Characteristic Propertyfor finite state automata Larsen, Ingolfsdottir, Sifakis, 1987 Ingolfsdottir, Steffen, 1994 a1 m1 n mk ak
Characteristic Propertyfor timed automata Larsen, Laroussinie, Weise, 1995 r1 a1 m1 g1 n Inv(n) gk mk ak rk IDEA_ Automata clocks become formula clocks
Characteristic Propertyfor timed automata Larsen, Laroussinie, Weise, 1995 r1 a1 m1 g1 n Inv(n) gk mk ak rk IDEA_ Automata clocks become formula clocks
Timed Safety LogicBack to Zones Larsen, Pettersson, Wang, 1995 Delay Modalities Atomic Prop Action Modalities Boolean Connectives Formula Clock Constr Recursion Variables Formula Clock Reset
Zone Semantics formula MC wrt Safety Logic is PSPACEcomplete location zone over C and K
Characteristic Property/Simulationfor deterministic timed automata Aceto, Burgueno,Bouyer, Larsen, 1998 r1 a m1 g1 n Inv(n) gk mk a rk gi and gj = Ø determinism