On composition and lookahead delegation of e-services modeled by automata

We study the decidability of composability and existence of k-delegators for various classes of machines M. Our results generalize earlier ones (and resolve some open questions) concerning composability of deterministic finite automata as e-services to finite automata that are augmented with unbounded storage (e.g., counters and pushdown stacks) and finite automata with discrete clocks (i.e., discrete timed automata). The results have applications to automated composition of e-services.