1. Demonstrate that the language L = {0^n1^n2^n : n N} is not context-free. (x^n means x to the power of n)

2. A 2-stack PDA is a PDA endowed with two stacks. At each step in a computation, a 2-stack PDA can push and/or pop in both stacks. The initial state of the stacks is empty, and the 2-stack PDA accepts with empty stacks. Prove that language L in Problem 1, can be recognized with a 2-stack PDA.