It has been shown recently that deterministic semiautomata can be represented by canonical words and equivalences; that work was motivated by the trace-assertion method for specifying software modules. Here, we generalize these ideas to a class of nondeterministic semiautomata. A semiautomaton is settable if, for every state q, there exists a word wq such that q, and no other state, can be reac...

We present our uni ed view to pattern matching problems and their solutions. We classify pattern matching problems by using six criteria and therefore we can locate them into six-dimensional space. We also show basic model of nondeterministic nite automaton that can be used for constructing models for all pattern matching problems.

This paper describes the design and implementation of lightgrep, a multipattern regular expression search tool that efficiently searches massive data streams. lightgrep addresses several shortcomings of existing digital forensic tools by taking advantage of recent developments in automata theory. The tool directly simulates a nondeterministic finite automaton, and incorporates a number of pract...

This paper provides a solution to the mandatory transformation example specified in MOLA – a graphical model transformation language developed at the University of Latvia. The solution is validated by executing it via the MOLA execution environment on several examples. In addition, a solution to one of the optional examples – determinization of a nondeterministic automaton is provided.

Counter automata are more powerful versions of finitestate automata where addition and subtraction operations are permitted on a set of n integer registers, called counters. We show that the word problem of Zn is accepted by a nondeterministic m-counter automaton if and only if m ≥ n.

We present our uni ed view to pattern matching problems and their solutions. We classify pattern matching problems by using six criteria and therefore we can locate them into six-dimensional space. We also show basic model of nondeterministic nite automaton that can be used for constructing models for all pattern matching problems.

We provide a new construction of a nondeterministic finite automaton (NFA) accepting the pushdown store language of a given pushdown automaton (PDA). The resulting NFA has a number of states which is quadratic in the number of states and linear in the number of pushdown symbols of the given PDA. Moreover, we prove the size optimality of our construction. Beside improving some results in the lit...

We show that the neighbourhood of a regular language L with respect to an additive quasi-distance can be recognized by an additive weighted finite automaton (WFA). The size of the WFA is the same as the size of an NFA (nondeterministic finite automaton) for L and the construction gives an upper bound for the state complexity of a neighbourhood of a regular language with respect to a quasi-dista...

Given two strings, a pattern P of length m and a text T of length n over some alphabet Σ of size σ, we consider the exact string matching problem, i.e. we want to report all occurrences of P in T . The well-known Backward-Nondeterministic-DAWG-Matching (BNDM) algorithm is one of the most efficient algorithm for short to moderate length patterns. In this paper – as a prelude – we take the underl...

A Linear Logic automaton is a hybrid of a finite automaton and a non-deterministic Petri net. LL automata commands are represented by propositional Horn Linear Logic formulas. Computations performed by LL automata directly correspond to cut-free derivations in Linear Logic. A programming language of LL automata is developed in which typical sequential, nondeterministic and parallel programming ...