Summary: A Really Temporal Logic \Lambday
Rajeev Alur Thomas A. Henzinger
AT&T Bell Laboratories Computer Science Department
600 Mountain Avenue Cornell University
Murray Hill, NJ 07974 Ithaca, NY 14853
Abstract. We introduce a temporal logic for the specification of real­time systems.
Our logic, TPTL, employs a novel quantifier construct for referencing time: the freeze
quantifier binds a variable to the time of the local temporal context. TPTL is both a
natural language for specification and a suitable formalism for verification. We present
a tableau­based decision procedure and a model checking algorithm for TPTL. Several
generalizations of TPTL are shown to be highly undecidable.
1 Introduction
Linear temporal logic is a widely accepted language for specifying properties of reactive systems
and their behavior over time [Pnu77, OL82, MP92]. The tableau­based satisfiability algorithm
for its propositional version, PTL, forms the basis for the automatic verification and synthesis of
finite­state systems [LP84, MW84].
PTL is interpreted over models that abstract away from the actual times at which events
occur, retaining only temporal ordering information about the states of a system. The analysis
of systems with hard real­time requirements, such as bounded response time, calls, however, for
the development of formalisms with explicit time. Several attempts have been made to introduce

Source: Alur, Rajeev - Department of Computer and Information Science, University of Pennsylvania
Henzinger, Thomas A. - Faculté Informatique et Communications, Ecole Polytechnique Fédérale de Lausanne

Collections: Computer Technologies and Information Sciences