Stateless multicounter 5'→3' Watson-Crick automata: the deterministic case

摘要

We consider stateless counter machines which mix the features of one-head counter machines and special two-head Watson-Crick automata (WK-automata). These biologically motivated machines have heads that read the input starting from the two extremes. The reading process is finished when the heads meet. The machine is realtime or non-realtime depending on whether the heads are required to advance at each move. A counter machine is k-reversal if each counter makes at most k alternations between increasing mode and decreasing mode on any computation, and reversal bounded if it is k-reversal for some k. In this paper we concentrate on the properties of deterministic stateless realtime WK-automata with counters that are reversal bounded. We give examples and establish hierarchies with respect to counters and reversals.