Conceptually, sets are simpler than sequences. The reason we took sequences first, though, is that we can implement sets in different ways to make operations more efficient, and some of these implementations are more complicated than the linked list data structure we made in the previous chapter.
There are many operations we might want for a set, for example, computing the union or intersection of two sets, but we will stick to the minimal interface we would expect a set to have. We want to be able to add elements to a ...
