(let ((entry (find tree old-new-alist :key #'second)))
(if entry (third entry) tree)))
((null (gethash tree *sharp-equal-circle-table*))
(setf (gethash tree *sharp-equal-circle-table*) t)
(let ((entry (find tree old-new-alist :key #'second)))
(if entry (third entry) tree)))
((null (gethash tree *sharp-equal-circle-table*))
(setf (gethash tree *sharp-equal-circle-table*) t)