We investigate the complexity of the containment problem "Does L(A) SUBSET OF OR EQUAL TO L(B) hold?" for register automata and timed automata, where B is assumed to be unambiguous and A is arbitrary. We prove that the problem is decidable in the case of register automata over (N,=), in the case of register automata over (Q,<) when B has a single register, and in the case of timed automata when B has a single clock.We give a 2-EXPSPACE algorithm in the first case, whose complexity is a single exponential in the case that B has a bounded number of registers.
In the other cases, we give an EXPSPACE algorithm.