4. It is not true that for any sets A and B we have A\\ (A \\ B) = B. (a) Explain why the above statement is false by explicitly writing down two sets, A and B for which the equality fails. (b) Is either of the statements A\\ (A \\ B) C B or B C A \\ (A \\ B) true for all sets A and B? (c) What simple set (in terms of A, B, their intersections, unions and so on) should replace B on the right side of the equality? Prove your assertion