anchor.diff:      result))
   
   (defun union-length (x y)
  -  "Returns length of union of two strings. This function is supposed to be
  -inlined."
  +  "Returns length of union of two strings X and Y. This function is supposed
  +to be inlined."
     (let ((temp (make-hash-table))
           (result 0))
       (declare (type array-index result)
  
positive.code:           (length y))))
  
  (defun jaccard (x y)
    "Calculates Jaccard similarity coefficient for two strings. Returned value
  is in range from 0 (no similarity) to 1 (exact match)."
    (declare (type (simple-array character) x y)
             (optimize (safety 0) (speed 3) (space 3)))
    (let ((x (string-to-set x))
  
negative.code:       (rotatef v0 v1))))
  
  (defun damerau-levenshtein (x y)
    "Calculate Damerau-Levenshtein distance between two given strings X and
  Y."
    (declare (type (simple-array character) x y)
             (inline length)
             (optimize (safety 0) (speed 3) (space 3)))
  