Deterministic Input-Reversal and Input-Revolving Finite Automata

Extended finite automata are finite state machines with the additional ability to manipulate the remaining part of the input. We investigate three types of deterministic extended automata, namely left-revolving, right-revolving, and input reversal finite automata. Concerning their computational capacity it is shown that nondeterminism is better than determinism, that is, for all three types of automata there is a language accepted by the nondeterministic versions but not accepted by any deterministic automaton of the same type. Concerning the closure properties most of the language families studied are not closed under standard operations. In particular, we show that the family of languages accepted by deterministic right-revolving finite automata is an anti-AFL which is not closed tinder reversal and intersection.