We consider a general class of decision problems concerning formal languages, called
“(one-dimensional) unboundedness predicates”, for automata that feature reversal-bounded …

In a jumping finite automaton, the input head can jump to an arbitrary position within the
remaining input after reading and consuming a symbol. We characterize the corresponding …

We study the reachability problem for affine Z-VASS, which are integer vector addition
systems with states in which transitions perform affine transformations on the counters. This …

Several variants of Parikh automata on infinite words were recently introduced by Guha et
al.[FSTTCS, 2022]. We show that one of these variants coincides with blind counter machine …

A class of languages C is perfect if it is closed under Boolean operations and the emptiness
problem is decidable. Perfect language classes are the basis for the automata-theoretic …

The class of languages captured by Constrained Automata (CA) that are unambiguous is
shown to possess more closure properties than the provably weaker class captured by …

Bounding the number of reversals in a counter machine is one of the most prominent
restrictions to achieve decidability of the reachability problem. Given this success, we …

Restrictions of reversal-bounded multicounter machines are studied; in particular, those that
cannot subtract from any counter until it has reached the end of the input. It is proven that this …

Well-structured transition systems (WSTS) are an abstract family of systems that
encompasses a vast landscape of infinite-state systems. By requiring a well-quasi-ordering …

Jumping automata are finite automata that read their input in a non-consecutive manner,
disregarding the order of the letters in the word. We introduce and study jumping automata …