We investigate several aspects of the multiple entry DFA’s. We consider their DFA conversion. Further, we show that they appear as minimal NFA’s for certain classes of languages. Finally, we deal with their decompositions into disjoint unions of automata with fewer states.

Unary self-verifying symmetric difference automata have a known tight bound of [Formula: see text] for their state complexity. We now consider the non-unary case and show that, every text], there is regular language accepted by nondeterministic automaton with states, such that its equivalent minimal deterministic finite has states. Furthermore, given any SV-XNFA it possible, up to isomorphism, ...

The concept of Deterministic Finite Cover Automata (DFCA) was introduced at WIA ’98, as a more compact representation than Deterministic Finite Automata (DFA) for finite languages. In some cases representing a finite language, Nondeterministic Finite Automata (NFA) may significantly reduce the number of states used. The combined power of the succinctness of the representation of finite language...

A Probabilistic I/O Automaton (PIOA) is a countable-state automaton model that allows nondeterministic and probabilistic choices in state transitions. A task-PIOA adds a task structure on the locally controlled actions of a PIOA as a means for restricting the nondeterminism in the model. The task-PIOA framework defines exact implementation relations based on inclusion of sets of trace distribut...

In the theory of automata the question about difference between the size of deterministic and nondeterministic automata which recognize the same language is of great importance. However, this problem has been studied mainly in case when input alphabet consists of at least 2 letters. In this paper some special kind of languages in one letter alphabet will be discussed and the estimate of the num...

We approach the problem of computing aD3-synchronizing word of minimum length for a given nondeterministic automaton via its encoding as an instance of SAT and invoking a SAT solver. We also present some experimental results.

We investigate the nondeterministic state complexity of basic operations for suffix-free regular languages. The nondeterministic state complexity of an operation is the number of states that are necessary and sufficient in the worst-case for a minimal nondeterministic finite-state automaton that accepts the language obtained from the operation. We consider basic operations (catenation, union, i...

A regular expression is called unambiguous if every tape in the event can be generated from the expression in one way only. The flow-graph technique for constructing an expression is shown to preserve ambiguities of the graph, and thus, if the graph is that of a deterministic automaton, the expression is unambiguous. A procedure for generating a nondeterministic automaton which preserves the am...

Discrete-event knowledge (DEK) consists in a variety of automaton-based data structures which are generated by knowledge-based and engineering systems, including intelligent diagnosis systems. Model-based methods for discrete-event systems (DESs) typically supported large automata that allow the efficient generation candidate diagnoses when DES is being operated. However, DEK may involve determ...

We show that language inclusion for languages of infinite words defined by nondeterministic automata can be tested in polynomial time if the automata are unambiguous and have simple acceptance conditions, namely safety or reachability conditions. An automaton with safety condition accepts an infinite word if there is a run that never visits a forbidden state, and an automaton with reachability ...