Prolog question!

Define a predicate isDuped so that isDuped(Y) succeeds if and only if Y is a list of the form of the lists Y in Exercise 10. That is, the predicate should succeed if and only if the first and second elements are equal, and the third and fourth elements are equal, and so on to the end of the list. It should fail for all odd-length lists.

Exercise 10: Define a dupList predicate so that dupList(X,Y) says that X is a list and Y is the same list, but with each element of X repeated twice in a row. For example, if X is [1, 3, 2], Y should be [1, 1, 3, 3, 2, 2]. If X is [], Y should be []. Check that your predicate works in both directitons - that is check that it works on queries like dupList(X, [1, 1, 3, 3, 2,2] as well as on queries like dupList ([1, 3,2], Y).