Learn More
Well-structured transition systems (WSTS's) are a general class of innnite state systems for which decidability results rely on the existence of a well-quasi-ordering between states that is compatible with the transitions. In this article, we provide an extensive treatment of the WSTS idea and show several new results. Our improved deenitions allow many(More)
In this thesis, we introduce a general method for computing the set of reachable states of an in nite-state system. The basic idea, inspired by well-known statespace exploration methods for nite-state systems, is to propagate reachability from the initial state of the system in order to determine exactly which are the reachable states. Of course, the(More)
We study Petri nets with Reset arcs (also Transfer and Doubling arcs) in combination with other extensions of the basic Petri net model. While Reachability is undecidable in all these extensions (indeed they are Turing-powerful), we exhibit unexpected frontiers for the decid-ability of Termination, Coverability, Boundedness and place-Boundedness. In(More)
This paper gives a simple and direct algorithm for computing the always regular set of reachable states of a pushdown system. It then exploits this algorithm for obtaining model checking algorithms for linear-time temporal logic as well as for the logic CTL . For the latter, a new technical tool is introduced: pushdown automata with transitions conditioned(More)