ω-automaton

About: ω-automaton is a research topic. Over the lifetime, 2299 publications have been published within this topic receiving 68468 citations. The topic is also known as: stream automaton & ω-automata.

Regular Expressions with Numerical Constraints and Automata with Counters

Abstract: Regular expressions with numerical constraints are an extension of regular expressions, allowing to bound numerically the number of times that a subexpression should be matched. Expressions in this extension describe the same languages as the usual regular expressions, but are exponentially more succinct. We define a class of finite automata with counters and a deterministic subclass of these. Deterministic finite automata with counters can recognize words in linear time. Furthermore, we describe a subclass of the regular expressions with numerical constraints, a polynomial-time test for this subclass, and a polynomial-time construction of deterministic finite automata with counters from expressions in the subclass.

Forest automata for verification of heap manipulation

Abstract: We consider verification of programs manipulating dynamic linked data structures such as various forms of singly and doubly-linked lists or trees. We consider important properties for this kind of systems like no null-pointer dereferences, absence of garbage, shape properties, etc. We develop a verification method based on a novel use of tree automata to represent heap configurations. A heap is split into several "separated" parts such that each of them can be represented by a tree automaton. The automata can refer to each other allowing the different parts of the heaps to mutually refer to their boundaries. Moreover, we allow for a hierarchical representation of heaps by allowing alphabets of the tree automata to contain other, nested tree automata. Program instructions can be easily encoded as operations on our representation structure. This allows verification of programs based on symbolic state-space exploration together with refinable abstraction within the so-called abstract regular tree model checking. A motivation for the approach is to combine advantages of automata-based approaches (higher generality and flexibility of the abstraction) with some advantages of separation-logic-based approaches (efficiency). We have implemented our approach and tested it successfully on multiple non-trivial case studies.

Algebraic Structures in Automata and Database Theory

Abstract: Part 1 Pure automata: main notions universal automata moors automata constructions decomposition of finite pure automata free pure automata generalizations. Part 2 Linear automata: main properties constructions decompositions of linear automata and biautomata automorphisms of linear automata. Part 3 Varieties of automata: identities of pure automata varieties of pure automata identities of linear automata and biautomata varieties of biautomata quasivarieties of automata. Part 4 Automaton's model of databases: *-automata polyadic and cylindric algebras universal *-automaton databases dynamical databases.

Once More on the Edge-Minimization of Nondeterministic Finite Automata and the Connected Problems

Abstract: We consider in this paper the problem of edge-minimization for nondeterministic finite automata and some connected questions. We shall formulate a new algorithm solving this problem; this algorithm is a simplification of two ones published before. The connected problems include at first algorithms of combining states. We formulate some new sufficient conditions for the possibility of such combining.

Triangle cellular automata

Abstract: This paper introduces a special class of cellular automata, called triangle cellular automata, which accept as input strings of length a power of two. In particular, we study the special case in which state information can only move upward through a complete binary tree of finite-state automata. It is shown that this class of cellular automata can accept various string languages in O(log n) time, where n is the length of the input string defining the initial states of the leaf vertices in the tree. Extensions to two dimensions, defining a pyramid cellular automaton, are also given.