 
   ## Example
 
-     tuple = { :foo, :bar, 3 }
-     elem(tuple, 1) #=> :bar
+      tuple = { :foo, :bar, 3 }
+      elem(tuple, 1) #=> :bar
 
   """
   defmacro elem(tuple, index) when is_integer(index) do


  ## Examples

      > list_to_integer('3FF', 16) #=> 1023
  """
  @spec list_to_integer(string, non_neg_integer), do: integer
  def list_to_integer(char_list, base) do


  ## Examples

      !1        #=> false
      ![1,2,3]  #=> false
      !false    #=> true
      !nil      #=> true

  """
  defmacro !arg
