PROLOG: Write a prolog predicate that counts occurrences of 'x', 'y', or 'z' in a list. For example, count([x,[y,[a,2],[a,3]],[a,4]], 2) should return true. I only want to count occurrences of x,y,z not a. the base case is that any [a,int] list will have a count of 0. So any sublist with 'a' does not count. another example of what will return true is: count([x,[a,1],[a,5]], 1) The predicate must have the form count(X,Y) where X is the list structure passed and Y is the count.