anchor.diff:                n)) ;p23
   
   ;;; p25
  +
   (defun rnd-permu (list)
     "Generate a random permutation of the elements of a list.
   Example:
  
positive.code:   (rnd-select list (length list))) ;p23
    
  ;;; p26
  (defun combination (k list)
    "Generate the combinations of K distinct objects chosen from the N elements of a list
  In how many ways can a committee of 3 be chosen from a group of 12 people? We all know that there are C(12,3) = 220 possibilities (C(N,K) denotes the well-known binomial coefficients). For pure mathematicians, this result may be great. But we want to really generate all the possibilities in a list.
  
negative.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.
  