Much is known about the differences in expressiveness and succinctness between nondeterministic and deterministic automata on infinite words. Much less is known about the relative succinctness of the different classes of nondeterministic automata. For example, while the best translation from a nondeterministic Büchi automaton to a nondeterministic co-Büchi automaton is exponential, and involves...

Abs t r ac t . Approximate string matching is a sequential problem and therefore it is possible to solve it using finite automata. A nondeterministic finite automaton is constructed for string matching with k mismatches. It is shown, how "dynamic programming" and "shift-and" based algorithms simulate this nondeterministic finite automaton. The corresponding deterministic finite automaton have O...

It is known that a nondeterministic input-driven pushdown automaton (IDPDA) (a.k.a. visibly pushdown automaton; a.k.a. nested word automaton) of size n can be transformed to an equvalent deterministic automaton of size 2 2) (B. von Braunmühl, R. Verbeek, “Input-driven languages are recognized in log n space”, FCT 1983), and that this size is necessary in the worst case (R. Alur, P. Madhusudan, ...

The complementation problem for nondeterministic word automata has numerous applications in formal verification. In order to check that the language of an automaton A1 is contained in the language of a second automaton A2, one checks that the intersection of A1 with an automaton that complements A2 is empty. Many problems in verification and design are reduced to language containment. In model ...

Li and Pedrycz [Y. M. Li, W. Pedrycz, Fuzzy finite automata and fuzzy regular expressions with membership values in lattice ordered monoids, Fuzzy Sets and Systems 156 (2005) 68–92] have proved fundamental results that provide different equivalentways to represent fuzzy languageswithmembership values in a lattice-orderedmonoid, and generalize the well-known results of the classical theory of fo...

We introduce a new kind of tree automaton, a dependency tree automaton, that is suitable for deciding properties of classes of terms with binding. Two kinds of such automaton are defined, nondeterministic and alternating. We show that the nondeterministic automata have a decidable nonemptiness problem and leave as an open question whether this is true for the alternating version. The families o...

We introduce a new kind of tree automaton, a dependency tree automaton, that is suitable for deciding properties of classes of terms with binding. Two kinds of such automaton are defined, nondeterministic and alternating. We show that the nondeterministic automata have a decidable nonemptiness problem and leave as an open question whether this is true for the alternating version. The families o...

We introduce and study three notions of typeness for automata on infinite words. For an acceptance-condition class γ (that is, γ is weak, Büchi, co-Büchi, Rabin, or Streett), deterministic γ-typeness asks for the existence of an equivalent γ-automaton on the same deterministic structure, nondeterministic γ-typeness asks for the existence of an equivalent γ-automaton on the same structure, and γ...

A sweeping automaton is a two-way deterministic finite automaton which makes turns only at the endmarkers. We say that a sweeping automaton is degenerate if the automaton has no left-moving transitions. We show that for each positive integer n, there is a nondeterministic finite automaton An over a two-letter alphabet such that An has n states, whereas the smallest equivalent nondegenerate swee...

We investigate the conversion of nondeterministic finite automata and context-free grammars into Parikh equivalent deterministic finite automata, from a descriptional complexity point of view. We prove that for each nondeterministic automaton with n states there exists a Parikh equivalent deterministic automaton with e √ n·lnn) states. Furthermore, this cost is tight. In contrast, if all the st...