anchor.diff:    (loop for s-count upto (* (length fitness-alist) (/ percentage 100)) collect
           (tournament-selection fitness-alist program-count)))
   
  -(defun crossover-population (fitness-alist &optional (percentage 10) (program-count 7))
  +(defun crossover-population (fitness-alist &optional (percentage 90) (program-count 7))
     (loop for s-count upto (* (length fitness-alist) (/ percentage 100)) collect
           (let ((mother (tournament-selection fitness-alist program-count))
                 (father (tournament-selection fitness-alist program-count)))
  
positive.code:     nil))
  
  (defun evaluate-population (population repeat-var args fargs)
    (mapcar #'(lambda (tree) (cons tree (evaluate-tree tree repeat-var args fargs))) population))
  
  (defun generation-fitness (population args fargs fitness-function &optional (repeat-var 50))
    (pairlis population
             (mapcar #'(lambda (result) (fitness-function result))
                     (evaluate-population population repeat-var args fargs))))
  
  (defun get-min-max (alist predicate key)
  
negative.code:   (let ((branches (cdr tree)))
      (if (is-tree branches)
        (let* ((pick-number (random (length branches)))
               (acc (append acc (list (+ 1 pick-number))))
               (pick (nth pick-number branches)))
          (if (fair-coin 75)
            (pick-random-subtree pick replacement acc)
            (if replacement acc pick)))
        (if replacement acc tree))))
  
  (defun recursive-nth (tree nth-list)
    (let ((target (nth (car nth-list) tree)))
  