Models of a generalized nondeterminism are defined by limitations on nondeterministic behavior of a computing device. A regular realizability problem is a problem of verifying existence of a special sort word in a regular language. These notions are closely connected. In this paper we consider regular realizability problems for languages consisting of all prefixes of an infinite word. These pro...

We consider modal transition systems with infinite state space generated by finite sets of rules. In particular, we extend process rewrite systems to the modal setting and investigate decidability of the modal refinement relation between systems from various subclasses. Since already simulation is undecidable for most of the cases, we focus on the case where either the refined or the refining p...

State explosion is a fundamental problem in the analysis and synthesis of discrete event systems. Continuous Petri nets can be seen as a relaxation of discrete models. The expected gains are twofold: improvements in comlexity and in decidability. This paper concentrates on the study of decidability issues. In the case of autonomous nets it is proved that properties like reachability, liveness o...

We prove the decidability for a class of languages which extend BST and NP-completeness subclass them. The extended with unordered cartesian product, ordered product powerset fall in this last subclass.

As a step towards resolving question of Ru\v{s}kuc on the decidability joint embedding for hereditary classes permutations, which may be viewed as structures in language 2 linear orders, we show corresponding problem is undecidable 3 orders.