The Decidability of the Equivalence Problem for DOL-Systems

FRISK Department of Computer Science, University of Waterloo, Waterloo, Ontario, Canada N2L 3GI The language and sequence equivalence problem for DOL-systems is shown to be decidable. In an algebraic formulation the sequence equivalence problem for DOL-systems can be stated as follows: Given homomorphisms h, and h, on a free monoid z1* and a word D from Z*, is %rn(r,) = &“(o) for all n > O?