Question 1.1 (Occurrences of an element) (a) Specify the number of occurrences of element x in list xs. (b) What does your specification give when xs=[] ? (c) Find an efficient algorithm that meets your specification. Question 1.2 (Specifying frequency) In the list [0,1,1,0,1,1,0] the value 1 occurs twice, which is minimal amongst frequency of elements in the list. Suppose xs:L(Z) is a list of integers. (a) Specify that xs has a duplicate element (i.e. an element occurring at least twice). The value of the duplicate does not matter. (b) Specify the frequency of a least-frequent value occurring in xs.1