n general, A − B and B − A do not denote the same set. (See Figure 2.26.) But your friends Evan and Yasmin wander by and tell you the following. Let E denote the set of CS homework questions that Evan...

n general, A − B and B − A do not denote the same set. (See Figure 2.26.) But your friends Evan and Yasmin wander by and tell you the following. Let E denote the set of CS homework questions that Evan has not yet solved. Let Y denote the set of CS homework questions that Yasmin has not yet solved. Evan and Yasmin claim that E − Y = Y − E. Is this possible? If so, under what circumstances? If not, why not? Justify your answer.