Extended Computation Tree Logic

We introduce a generic extension of the popular branching-time logic CTL which refines the temporal until and release operators with formal languages. For instance, a language may determine the moments along a path that an until property may be fulfilled. We consider several classes of languages leading to logics with different expressive power and complexity, whose importance is motivated by their use in model checking, synthesis, abstract interpretation, etc. We show that even with context-free languages on the until operator the logic still allows for polynomial time model-checking despite the significant increase in expressive power. This makes the logic a promising candidate for applications in verification. In addition, we analyse the complexity of satisfiability and compare the expressive power of these logics to CTL* and extensions of PDL

Quantified Mu-calculus for Control Synthesis

We consider an extension of the mu-calculus as a general framework to describe and synthesize controllers. This extension is obtained by quantifying atomic propositions, we call the resulting logic quantified mu-calculus. We study its main theoretical properties and show its adequacy to control applications. The proposed framework is expressive : it offers a uniform way to describe as varied parameters as the kind of systems (closed or open), the control objective, the type of interaction between the controller and the system, the optimality criteria (fairness, maximally permissive), etc. To our knowledge, none of the former approaches can capture such a wide range of concept

Synthesizing Enforcement Monitors wrt. the Safety-Progress Classification of Properties

Abstract. Runtime enforcement is a powerful technique to ensure that a program will respect a given security policy. We extend previous works on this topic in several directions. Firstly, we propose a generic notion of enforcement monitors based on a memory device and finite sets of control states and enforcement operations. Moreover, we specify their enforcement abilities w.r.t. the general safety-progress classification of properties. It allows a fine-grain characterization of the space of enforceable properties. Finally, we propose a systematic technique to produce an enforcement monitor from the Streett automaton recognizing a given safety, guarantee, obligation or response security property.