A NOTE ON REAL-TIME ONE-WAY ALTERNATING MULTICOUNTER MACHINES

This paper investigates several properties of one-way alternating multicounter machines which operate in real time, and shows that (1) for each k greater-than-or-equal-to 1, one-way alternating k-counter machines (1 acm(k)'s) which operate in real time are less powerful than 1acm(k + 1)'s which operate in real time, (2) for each k greater-than-or-equal-to 2, 1acm(k)'s which operate in real time are less powerful than 1acm(k)'s which operate in linear time, and (3) for each k greater-than-or-equal-to 1, the class of sets accepted by 1acm(k)'s which operate in real time is not closed under concatenation with regular sets, Kleene closure, reversal and length-preserving homomorphism.