Rewrite rule grammars with multitape automata

Quantum Finite Multitape Automata

Quantum finite automata were introduced by C. Moore, J. P. Crutchfield [MC 97], and by A. Kondacs and J. Watrous [KW 97]. This notion is not a generalization of the deterministic finite automata. Moreover, in [KW 97] it was proved that not all regular languages can be recognized by quantum finite automata. A. Ambainis and R. Freivalds [AF 98] proved that for some languages quantum finite automa...

Size Reduction of Multitape Automata

The Equivalence Problem of Multitape Finite Automata

Using a result of B.H. Neumann we extend Eilenberg’s Equality Theorem to a general result which implies that the multiplicity equivalence problem of two (nondeterministic) multitape finite automata is decidable. As a corollary we solve a long standing open problem in automata theory, namely, the equivalence problem for multitape deterministic finite automata. The main theorem states that there ...

The equivalence problem of multidimensional multitape automata

This article considers the equivalence problem of multitape automata with multidimensional tapes, where the motion of the heads is monotone in all directions (no backward motion). It is shown that this problem can be reduced to the equivalence problem of ordinary multitape automata. Some applications of the result are adduced. © 2008 Elsevier Inc. All rights reserved.

Derived-Term Automata of Multitape Rational Expressions

We consider (weighted) rational expressions to denote series over Cartesian products of monoids. We define an operator | to build multitape expressions such as (a | x+ b | y)∗. We introduce expansions, which generalize the concept of derivative of a rational expression, but relieved from the need of a free monoid. We propose an algorithm based on expansions to build multitape automata from mult...