Define a PDA-2 to be a PDA (push down automation) with two stacks (instead of one). Assume that the stacks can be manipulated independently and that the machine accepts if and only if it is in an accepting state and both stacks are empty when it runs out of input. De- scribe the operation of a PDA-2 that accepts Aⁿ BⁿCⁿ = { aⁿbⁿcⁿ: n c>= 0}.