5,259 research outputs found
Refinement Calculus of Reactive Systems
Refinement calculus is a powerful and expressive tool for reasoning about
sequential programs in a compositional manner. In this paper we present an
extension of refinement calculus for reactive systems. Refinement calculus is
based on monotonic predicate transformers, which transform sets of post-states
into sets of pre-states. To model reactive systems, we introduce monotonic
property transformers, which transform sets of output traces into sets of input
traces. We show how to model in this semantics refinement, sequential
composition, demonic choice, and other semantic operations on reactive systems.
We use primarily higher order logic to express our results, but we also show
how property transformers can be defined using other formalisms more amenable
to automation, such as linear temporal logic (suitable for specifications) and
symbolic transition systems (suitable for implementations). Finally, we show
how this framework generalizes previous work on relational interfaces so as to
be able to express systems with infinite behaviors and liveness properties
Control design for hybrid systems with TuLiP: The Temporal Logic Planning toolbox
This tutorial describes TuLiP, the Temporal Logic Planning toolbox, a collection of tools for designing controllers for hybrid systems from specifications in temporal logic. The tools support a workflow that starts from a description of desired behavior, and of the system to be controlled. The system can have discrete state, or be a hybrid dynamical system with a mixed discrete and continuous state space. The desired behavior can be represented with temporal logic and discrete transition systems. The system description can include uncontrollable variables that take discrete or continuous values, and represent disturbances and other environmental factors that affect the dynamics, as well as communication signals that affect controller decisions
Towards the Correctness of Software Behavior in UML: A Model Checking Approach Based on Slicing
Embedded systems are systems which have ongoing interactions with their environments, accepting requests and producing responses. Such systems are increasingly used in applications where failure is unacceptable: traffic control systems, avionics, automobiles, etc. Correct and highly dependable construction of such systems is particularly important and challenging. A very promising and increasingly attractive method for achieving this goal is using the approach of formal verification. A formal verification method consists of three major components: a model for describing the behavior of the system, a specification language to embody correctness requirements, and an analysis method to verify the behavior against the correctness requirements. This Ph.D. addresses the correctness of the behavioral design of embedded systems, using model checking as the verification technology. More precisely, we present an UML-based verification method that checks whether the conditions on the evolution of the embedded system are met by the model. Unfortunately, model checking is limited to medium size systems because of its high space requirements. To overcome this problem, this Ph.D. suggests the integration of the slicing (reduction) technique
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