Implemented sets in Scheme
Converts lists into sets (no duplicate elements). Functions defined: empty?, set, in?, add, discard, union, intersection, difference (the difference of 2 sets, written A-B, is the set of all elements of A that aren’t elements of B), symmetric-difference (elements in either but not both), subset?, superset?, disjoint?, and sameset?. There are several pre-provided tests towards the end of the file that involve converting lists to sets, and then trying all functions on those sets.