<ol>
  <li>
    Write a function <code>print_int_list : int list -> unit</code>
    that takes a list of integers as input, and prints all the
    elements of the list, each on its own line.
  </li>
  <li>
    Write a function <code>print_every_other : int -> int list ->
    unit</code> that takes a value k and a list of integers as input,
    and prints the elements of the list that are in positions multiple
    of k, each on its own line. Note: the first element of a list is
    at the position 0, not 1.
  </li>
  <li>
    Write a function <code>print_list : ('a -> unit) -> 'a list ->
    unit</code> that takes a printer of values of some
    type <code>'a</code> and a list of such values as input, and
    prints all the elements of the list, each on its own line.
  </li>
</ol>
