anchor.diff:      "expl"  "dislocated"
       "advcl" "advmod"
       "discourse"
  -    "aux" "cop"
  -    "mark" "nmod"
  -    "appos"
  +    "aux"  "cop"
  +    "mark" "nmod" "appos"
       "nummod"
       "acl"
       "amod"
  
positive.code: 				     list-sent2)
  			     :key #'length
  			     :initial-value 0)))
      (- (1 (/ (float wrong-words)
  	     total-words)))))
  
  
  (defun recall (list-sent1 list-sent2 deprel &key (head-error nil) (label-error t) (simple-deprel nil))
  
negative.code:   "Attachment score by sentence (macro-average).
  
     The attachment score is the percentage of words that have correct
     arcs to their heads. The unlabeled attachment score (UAS) considers
     only who is the head of the token, while the labeled attachment
     score (LAS) considers both the head and the arc label (dependency
     label / syntactic class).
  
     References:
       - Dependency Parsing - Kubler, Mcdonald and Nivre (pp.79-80)"
    (let ((ns (mapcar #'(lambda (x y)
  			(- 1.0
  			   (/ (length (sentence-diff x y :fields fields
  						     :punct punct
  						     :simple-dep simple-dep))
  			      (sentence-size y))))
  		    list-sent1 list-sent2)))
      (/ (apply #'+ ns) (float (length ns)))))
  
  
  (defun attachment-score-by-word (list-sent1 list-sent2 &key (fields *token-fields*)
  							 (punct t) (simple-dep nil))
    "Attachment score by word (micro-average). See also the
    `attachment-score-by-sentence`.
  
     References:
       - Dependency Parsing - Kubler, Mcdonald and Nivre (pp.79-80)"
  