18. (28 points) (ab), L (w: w ab'). List the indistinguishability equivalence ci for L. For each class: classes .Give examples of strings in the class, and a verbal description of the class. State whether or not strings in the class are in L. +2 for wz to be in L, and if so, which properties z must have. List the class transitions for each element in . , and wz is a string in the class concatenated with z. State whether it is possible