We propose a new approach for automatic verification of programs with dynamic heap manipulation. The method is based on symbolic (backward) reachability analysis using upward-closed sets of heaps w.r.t. an appropriate preorder on graphs. These sets are represented by a finite set of minimal graph patterns corresponding to a set of bad configurations. We define an abstract semantics for the prog...

We present a simulation preorder for reactive systems modeled by fair Kripke structures whose transition relation is divided into two parts, internal and external. The first one models the internal behaviour of the system, while the second one is used to model the interaction with an environment. We show that our simulation preorder preserves a substantial subset of ∀CTL∗. Then, we present an a...

Consider the following curious puzzle: call an n-tuple X = (X1, . . . , Xn) of sets smaller than another ntuple Y if it has fewer unordered sections. We show that equivalence classes for this preorder are very easy to describe and characterize the preorder in terms of the simpler pointwise inclusion and the existence of a special increasing boolean operator f : B → B. We also show that contrary...

A testing scenario in the sense of De Nicola and Hennessy is developed to measure the worst-case eeciency of asynchronous systems using dense time, and it is shown that one can equivalently use discrete time. The resulting testing-preorder is characterized with some kind of refusal traces. Furthermore, the testing-preorder is reened to a precongruence for standard operators known from process a...

We consider decidability questions for simulation preorder (and equivalence) for processes generated by one-counter machines. We sketch a proof of decidability in the case when testing for zero is not possible, and demonstrate the undecidability in the general case.

TACS is an extension of CCS where upper time bounds for delays can be specified. Lüttgen and Vogler defined three variants of bismulation-type faster-than relations and showed that they all three lead to the same preorder, demonstrating the robustness of their approach. In the present paper, the operational semantics of TACS is extended; it is shown that two of the variants still give the same ...

Recently, Abdulla and Čerāns (1998) outlined an extensive and involved proof of the decidability of simulation preorder for one-counter nets. In this note, we present a short, complete proof based on simple colourings of the plane.1 1This paper was written during a visit by the first author to Uppsala University supported by a grant from the STINT Fellowship Programme. He is also partially supp...

We consider the problem of simulation preorder/equivalence between in nitestate processes and nite-state ones. We prove that simulation preorder (in both directions) and simulation equivalence are intractable between all major classes of in nite-state systems and nite-state ones. This result is obtained by showing that the problem whether a BPA (or BPP) process simulates a nite-state one is PSP...

Variants of the must testing approach have been successfully applied in Service Oriented Computing for analysing the compliance between (contracts exposed by) clients and servers or, more generally, between two peers. It has however been argued that multiparty scenarios call for more permissive notions of compliance because partners usually do not have full coordination capabilities. We propose...

We consider the problem of simulation preorder/equivalence between infinite-state processes and finite-state ones. We prove that simulation preorder (in both directions) and simulation equivalence are intractable between all major classes of infinite-state systems and finite-state ones. This result is obtained by showing that the problem whether a BPA (or BPP) process simulates a finitestate on...