Forward analysis for WSTS, part II: Complete WSTS

Abstract

We describe a simple, conceptual forward analysis procedure for ∞-complete WSTS . This computes the clover of a state s 0, i.e., a finite description of the closure of the cover of s 0. When is the completion of a WSTS , the clover in is a finite description of the cover in . We show that this applies exactly when is an ω 2 -WSTS, a new robust class of WSTS. We show that our procedure terminates in more cases than the generalized Karp-Miller procedure on extensions of Petri nets. We characterize the WSTS where our procedure terminates as those that are clover-flattable. Finally, we apply this to well-structured counter systems. © 2009 Springer Berlin Heidelberg.