or not infinitely many terms of a linear recurrence sequence vanish is given in terms of the Residue Theorem of complex variable theory, A decidable case, based on transcenedental number Theory is also discussed. The last section details an approach to the problem based on polynomial ideal theory.

to such claims, which clearly formed the conventional wisdom about case-study research. I decided therefore to find out where the claims come from and whether they are correct. This chapter contains what I discovered.

We introduce and investigate the notion of weak morphisms of trace monoids with the aim of dealing with the problem of deciding the existence of codings between trace monoids. We prove that this problem is not recursively enumerable, which answers the question raised by Ochmanski in 1988

boundary between decidability and undecidability for the reachability problem of hybrid automata. On the positive side, we give an (optimal) PSPACE reachability algorithm for the case of initialized rectangular automata, where all analog variables follow independent trajectories within piecewise

with the network, plans, decides and acts on this information. Cognitive networks are different from other “intelligent ” communication technologies because these actions are taken with respect to the end-to-end goals of a data flow. In addition to the cognitive aspects of the network, a specification language

RON is an application-layer overlay on top of the existing Internet routing substrate. The RON nodes monitor the functioning and quality of the Internet paths among themselves, and use this information to decide whether to route packets directly over the Internet or by way of other RON nodes

been extended and modified. This executable semantics has been in operation in driving the simulation, dynamic tests, and code generation tDols of STATEMATE since 1987, and a technical report describing it has been available from i-Logix, Inc. since 1989. We have now decided to revise and publish

communication events being unobservable is relaxed, i.e., communication events could be either observable or unobservable. Then, we discuss about the decidable case where communication events are all observable and develop a new efficient algorithm to test it. Finally, we also provide an important property

Semi-unification is a common generalization of unification and matching. The semiunification problem is to decide solvability of finite sets of equations s = t and inequations ˜s ≤i ˜t between first-order terms, with different inequality relations ≤i, i ∈ I. A solution consists of a substitution T0

atoms are complex expressions. We present the following results on query containment. For the case where q does not contain regular expressions, we provide a method for deciding query containment, and analyze its computational complexity. We do the same for the case where neither S nor q, q ′ contain