anchor.diff:  	     (e2 (cdr second)))
   
   	  (setf (bmg:goodness e1)
  -	      (/ 1 (+ (/ 1 (max (bmg:goodness e1)) (/ 1 (bmg:goodness e2))))))
  +		(combine-parallel-edge-weights
  +		 (mapcar #'bmg:goodness (list e1 e2))))
  +
   	  (bmg:remove-edge e2)
   	  (incf removed))))
       removed))
  
positive.code: 
  (defun remove-parallel-edges (graph)
    (let
        ((removed 0))
      (loop do
  	 (let
  	     ((removed-this-round (remove-parallel-edges-helper graph)))
  	   (incf removed removed-this-round)
  
  	   (when (= 0 removed-this-round)
  	     (progn
  	       (format *error-output* "Removed ~A parallel edges~%" removed)
  	       (return-from remove-parallel-edges removed)))))))
  
  
  (defun randomized-bfs (start-node goal-node
  
negative.code: 	   (remove-serial-node graph (first candidates))))))
  
  
  (defun combine-parallel-edge-weights (weights)
    (- 1 (apply #'* (mapcar #'(lambda (weight) (- 1 weight)) weights))))
  
  
  (defun remove-parallel-edges-helper (graph)
    (let*
        ((removed 0)
  