We introduce a hierarchy of fast-growing complexity classes and show its suitability for
completeness statements of many nonelementary problems. This hierarchy allows the …

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 …

Well-quasi-orderings (wqos)(Kruskal, 1972) are a fundamental tool in logic and computer
science. ey provide termination arguments in a large number of decidability (or finiteness …

We consider the model of history-deterministic one-counter nets (OCNs). History-
determinism is a property of transition systems that allows for a limited kind of non …

A k-Counter Net (k-CN) is a finite-state automaton equipped with k integer counters that are
not allowed to become negative, but do not have explicit zero tests. This language …

One Counter Nets (OCNs) are finite-state automata equipped with a counter that cannot
become negative, but cannot be explicitly tested for zero. Their close connection to various …

Equivalence of deterministic pushdown automata is a famous problem in theoretical
computer science whose decidability has been shown by Sénizergues. Our first result shows …

We study languages of unambiguous VASS, that is, Vector Addition Systems with States,
whose transitions read letters from a finite alphabet, and whose acceptance condition is …

We study decidability of verification problems for timed automata extended with unbounded
discrete data structures. More detailed, we extend timed automata with a pushdown stack. In …

In the early two-thousands, Recursive Petri nets have been introduced in order to model
distributed planning of multi-agent systems for which counters and recursivity were …