MCS-287 Homework 2 (Spring 2026)

First draft due on Monday, 2/9/2026, by the start of class
Second draft (provided first draft recieves a grade of 60% and up) due on Monday, 3/9/2026, by the start of class

• Do exercise 6.2 on page 102. In each case, the given set is the type's set of values.
• Do exercise 6.4 on page 102.
• Exercise 7.x1: Given this definition:

  fun mystery(a, b::bs) =
     if a = b then
        mystery(a, bs)
     else
        b::mystery(a, bs)
    | mystery(a, []) = [];
  

  What is the type of mystery? What is the value of mystery(3,[3,2,1,2,3])? What happens if you try mystery(3.0,[3.0,2.0])? Why?
• Do exercise 8.1 on page 130. Show your result by labeling each of the nine plus signs with a three letter abbreviation of its type, for example irr for int*real->real.
• Do exercise 8.5 on page 131.
• Exercise 9.x1: Show how foldr and map can be used in ML to start with the list [4,5,6] and produce the list [8,8,10,10,12,12], in which each value has been "doubled" in two senses of the word: multiplied by two and repeated twice.