For all problems below, you only need to make sure that the predicates correctly find the first solution, as in the examples provided. You do NOT need to worry about what happens when asking for more solutions (with ";").

1. (56 pts) Consider an implementation of sets with Prolong lists. A set is an unordered collection of elements, without duplicates.

b. (14 pts) Write the rules for a predicate subset (A, S), which succeeds if the set A is a subset of the set S. The following query shows an example of using this predicate:

?- subset ([2, 5], [1, 5, 3, 2])

True