Problem: Implement function pairLists/2 that takes two lists of numbers, L1 and L2, as the parameters, and returns a list of tuples composed of the corresponding elements of L1 and L2. For example, pairLists([1,2,3],[a,b,c]) shall return [(1,a),(2,b),(3,c)]. The function shall not make any assumptions about the relative lengths of L1 and L2.