Regularity and Related Problems for Deterministic Pushdown Automata

Abstract

It iS shown that to decide whether the language accepted by an arbitrary deterministic pushdown automaton is LL (k), or whether it m accepted by some one-counter or finite-turn pushdown machine, must be at least as difficult as to decide whether it is regular. The regularity problem itself is analyzed in detail, and Stearns’ decimon procedure for this as improved by one level of exponentiatlon Upper bounds, close to known lower bounds, are obtained for the succinctness with which a pushdown automaton, and various restrictions of it, can express equivalent fimte-state machines. © 1975, ACM. All rights reserved.