(defun conflict-resolution (conflict-resolution-function instantiations)
	"apply a conflict resolution strategy function to the set of instantiations
	   generated by get-all-instantiationst and the LHS functions it calls"
  (funcall conflict-resolution-function instantiations))
   
; a candidate for depth first
(defun CR-first (instantiation-list)
  (first instantiation-list))

(defun get-time-tags (instantiation)
  "returns list of time tags for an instantiation"
  (let ((binding-list (rest instantiation)))
    (remove-if #'null
               (mapcar (lambda (b)
                         (if (not (instance-binding-p (binding-val b))) nil
                             (TT-val (binding-val b))))			
                       binding-list))))


(defun insert-sorted-tags (conflict-set)
    "inserts list of time tags into instantiations of conflict set
after this function, and instantion will look like the following:
(rule-name <sorted list of time tags> <binding list>)"    
     (mapcar (lambda (instantiation)
            (append (list (first instantiation))
                    (list (sort (get-time-tags instantiation) #'>))
                    (rest instantiation)))
          conflict-set))