Abstract
We study the equivalence problem for languages defined by various types of transducers acting on D0L languages. We show that, given ϵ-free sequential transducers S 1, …, S k , T 1, …, T k and D0L languages L 1, L 2, whether or not |S 1|(L 1)∪···∪|S k |(L 1)=|T 1|(L 2)∪···∪|T k |(L 2) is decidable.