Abstract. In [1] the notion of the general product of nondeterministic automata was introduced, and the isomorphically and homomorphically complete systems were studied. It was proved that there are finite complete systems for both representations and also a characterization was given for the isomorphic case. In this work we deal with the isomorphic representation of nondeterministic automata with respect to the cube-product introduced for deterministic automata in [2]. We characterize isomorphically complete systems for this product, from which it will follow that the general product and the cube-product are equivalent with respect to the isomorphic completeness.

AMS Subject Classification (1991): 68Q

Received May 4, 1994 and in revised form September 14, 1994. (Registered under 5635/2009.)