anchor.diff:    
     (is
      (n-times-average
  -    20
  +    5
       (trivial-garbage:gc :full t)
       (let* ((a9a-forest
                (make-forest 2 a9a-datamatrix a9a-target
  
positive.code: 
  (is
   (n-times-average
    20
    (trivial-garbage:gc :full t)
    (let ((a9a-forest
            (make-forest 2 a9a-datamatrix a9a-target
  
negative.code: 
    (is
     (n-times-average
      5
      (trivial-garbage:gc :full t)
      (let* ((letter-forest
               (make-forest letter-n-class letter-datamatrix letter-target
  