anchor.diff:  
     (is
      (n-times-average
  -    20
  +    5
       (trivial-garbage:gc :full t)
       (let* ((letter-forest
                (make-forest letter-n-class letter-datamatrix letter-target
  
positive.code:              "https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary/a9a.t"
               "-O" (format-pathname file.t))))))
  
  (defun approximately-equal (x y &optional (delta 0.2d0))
    (flet ((andf (x y) (and x y))
           (close? (x y) (< (abs (- x y)) delta)))
      (etypecase x
  
negative.code: 
  (is
   (n-times-average
    5
    (trivial-garbage:gc :full t)
    (let ((a9a-forest
            (make-forest 2 a9a-datamatrix a9a-target
  