anchor.diff:  						      (vector (t 6 11) (t 51 56))))
   		      (make-instance 'segment-term-vector
   				     :field "field2"
  -				     :terms (vector "word3" "word4")
  +				     :terms (vector "word3" "woord4")
   				     :term-frequencies (vector 1 5)
   				     :positions (vector (vector 8)
   							(vector 2 9 11 34 56))
  
positive.code: 		     (list
  		      (make-instance 'segment-term-vector
  				     :field "field1"
  				     :terms (vector "word1" "word2")
  				     :term-frequencies (vector 3 2)
  				     :positions (vector (vector 1 5 8)
  							(vector 2 9))
  
negative.code: 		     (list
  		      (make-instance 'segment-term-vector
  				     :field "field1"
  				     :terms (vector "word1" "woord2")
  				     :term-frequencies (vector 3 2)
  				     :positions (vector (vector 1 5 8)
  							(vector 2 9))
  