anchor.diff:  
   (defun reset-mse (nn)
     "Reset the current MSE"
  -  (fann-internal:fann-reset-mse (%pointer nn)))+  (fann-internal:fann-reset-mse (%pointer nn)))
  
positive.code:    (length :initarg :length)))
  
  (defmethod print-object ((object train-data) stream)
    (with-slots (num-inputs num-outputs) object
      (print-unreadable-object (object stream :type t :identity t)
        (format stream "data")))
    object)
  
  ;;;; Construction
  
negative.code: 		 ((vectorp data) (coerce data 'list))
  		 ((numberp data) (list data))
  		 (t (error "Each input must be a number or a sequence of numbers")))))
        (format stream "~d ~d ~d~%" N 
  	      (length (convert-data (elt inputs 0)))	      
  	      (length (convert-data (elt outputs 0))))
        (map nil
  	   #'(lambda (in out)
  	       (format stream "~{~5$~^ ~}~%~{~5$~^ ~}~%" 
  		       (convert-data in) 
  		       (convert-data out)))
  	   inputs
  