


-- Exercises
-- 1. Give another possible calculation
 -- for the result of double ( double 2).
-- 2. Show that sum [ x ] = x for any number x .
-- 3. Define a function product that produces the product of a list of numbers,
-- and show using your definition that product [2, 3, 4] = 24.
-- 4. How should the definition of the function qsort be modified so that it
-- produces a reverse sorted version of a list?
-- 5. What would be the effect of replacing ≤ by < in the definition of qsort ?
-- Hint: consider the example qsort [2, 2, 3, 1, 1].


