anchor.diff:  			      (x p0))
   			  (<= (x p0)
   			      (x maximum)))
  -		 (setf (status result) "Intersection")
  +		 (setf (status result) :INTERSECTION)
   		 (appendPoint result p0)))
   
   	      (t
   	       (when (and (ge p0 minimum)
   			  (le p0 maximum))
  -		 (setf (status result) "Intersection")
  +		 (setf (status result) :INTERSECTION)
   		 (appendPoint result p0))))))
       result))
   
   (defun bezier3-line-intersection (p1 p2 p3 p4 a1 a2)
     (let* ((i (make-instance 'Intersection))
   	 (j (intersect-bezier3-line i p1 p2 p3 p4 a1 a2)))
  -    (when(string/= (status j) "No intersection")
  +    (when (not (eql (status j) :NO-INTERSECTION))
         (points j))))
  
positive.code: 
  (defclass Intersection ()
    ((status :accessor status :initarg :status
  	   :initform "")
     (points :accessor points :initarg :points
  	   :initform (make-array 4
  				 :element-type 'Point2D
  
negative.code: 			      (y p0))
  			  (<= (y p0)
  			      (y maximum)))
  		 (setf (status result) :INTERSECTION)
  		 (appendPoint result p0)))
  
  	      ((= (y a1) (y a2))
  