More than 30 years after their inception, the decidability proofs for reach ability in vector
addition systems (VAS) still retain much of their mystery. These proofs rely crucially on a …

Tree structures are used extensively in domains such as computational biology, pattern
recognition, XML databases, computer networks, and so on. In this paper, we present …

Using arch-jum** functions and properties of the arch factorization of words, we propose a
new algorithm for computing the subword circular universality index of words. We also …

A recent breakthrough by Künnemann, Mazowiecki, Schütze, Sinclair-Banks, and Węgrzycki
(ICALP 2023) bounds the running time for the coverability problem in d-dimensional vector …

We consider the problems of language inclusion and language equivalence for Vector
Addition Systems with States (VASSes) with the acceptance condition defined by the set of …

In the language-theoretic approach to refinement verification, we check that the language of
traces of an implementation all belong to the language of a specification. We consider the …

The piecewise testable separability problem asks, given two input languages, whether there
exists a piecewise testable language that contains the first input language and is disjoint …

The well-quasi-ordering (ie, a well-founded quasi-ordering such that all antichains are finite)
that defines well-structured transition systems (WSTS) is shown not to be the weakest …

We show that the coverability problem in ν-Petri nets is complete for'double Ackermann'time,
thus closing an open complexity gap between an Ackermann lower bound and a hyper …

Well-structured transition systems form a large class of infinite-state systems, for which safety
verification is decidable thanks to a generic backward coverability algorithm. However, for …