4 research outputs found
Monotonic Abstraction Techniques: from Parametric to Software Model Checking
Monotonic abstraction is a technique introduced in model checking
parameterized distributed systems in order to cope with transitions containing
global conditions within guards. The technique has been re-interpreted in a
declarative setting in previous papers of ours and applied to the verification
of fault tolerant systems under the so-called "stopping failures" model. The
declarative reinterpretation consists in logical techniques (quantifier
relativizations and, especially, quantifier instantiations) making sense in a
broader context. In fact, we recently showed that such techniques can
over-approximate array accelerations, so that they can be employed as a
meaningful (and practically effective) component of CEGAR loops in software
model checking too.Comment: In Proceedings MOD* 2014, arXiv:1411.345
IST Austria Thesis
Motivated by the analysis of highly dynamic message-passing systems, i.e. unbounded thread creation, mobility, etc. we present a framework for the analysis of depth-bounded systems. Depth-bounded systems are one of the most expressive known fragment of the π-calculus for which interesting verification problems are still decidable. Even though they are infinite state systems depth-bounded systems are well-structured, thus can be analyzed algorithmically. We give an interpretation of depth-bounded systems as graph-rewriting systems. This gives more flexibility and ease of use to apply depth-bounded systems to other type of systems like shared memory concurrency.
First, we develop an adequate domain of limits for depth-bounded systems, a prerequisite for the effective representation of downward-closed sets. Downward-closed sets are needed by forward saturation-based algorithms to represent potentially infinite sets of states. Then, we present an abstract interpretation framework to compute the covering set of well-structured transition systems. Because, in general, the covering set is not computable, our abstraction over-approximates the actual covering set. Our abstraction captures the essence of acceleration based-algorithms while giving up enough precision to ensure convergence. We have implemented the analysis in the PICASSO tool and show that it is accurate in practice. Finally, we build some further analyses like termination using the covering set as starting point
Monotonic Abstraction in Parameterized Verification
AbstractWe present a tutorial on verification of safety properties for parameterized systems. Such a system consists of an arbitrary number of processes which are organized in a linear array. The aim is to prove correctness of the system regardless of the number of processes inside the system. We give an overview of the method of monotonic abstraction, which provides an over-approximation of the transition system induced by a parameterized system. The over-approximation gives a transition system which is monotonic with respect to a well quasi-ordering on the set of configurations. This makes it possible to use existing methods for verification of well quasi-ordered programs