anchor.diff:           (cons i (range (1+ i) k)))))
            
   ;;; p23
  +
   (defun rnd-select (list k)
     "Extract a given number of randomly selected elements from a list.
   The selected items shall be returned in a list.
  
positive.code:                         (1- k))))))
                          
  ;;; p24
  (defun lotto-select (n m)
    "Lotto: Draw N different random numbers from the set 1..M.
  The selected numbers shall be returned in a list.
  
negative.code: ;;;; Further index operations
  
  ;;; p22
  
  (defun range (i k)
    "Create a list containing all integers within a given range.
  If first argument is smaller than second, produce a list in decreasing order.
  