Let A={1, 2, 3, 4}. The function f: P(A) - P(A) is defined as: for every X E P(A), f (X) = (X n {1,2]) U {4). For example, f ({1, 3]) = {1, 4). Note: P(A) is the powerset of A (a set with all A's subsets) Find the range of f