Consider a new type of deterministic machine, having one read-only input tape and two stacks.The tape is read-only, it cannot be written, but the head can move left, right, or do nothing. Each stack operates, independently of the other, as in a deterministic pushdown automaton:

M= (K, , 1, 2, z1, z2, , s)

where K is a finite set of states, is a finite input alphabet, 1 and 2 are two finite stack alphabets (1 for the first stack, 2 for the second stack), z1 1 and z2 2 are the initial symbols for the two stacks, s K is the initial state. h is a special halting state not in K, just like in a Turing machine.

(b). These machines can accept the same languages as a class of automata you already know: deterministic pushdown automata, pushdown automata, or Turing machines? Prove your answer formally.