(defun temperature-conversion(lst)
  (cond
  ((member 'F lst) (F-to-C))
  ((member 'C lst) (C-to-F))
  (t (print "You didn't enter a valid unit for conversion"))
  )
)
(defun F-to-C()
;;(print "hello")
 (print (temperature-conversion(lst)))
)
(defun C-to-F()
(print "goodbye"))
;;(print (temperature-conversion '(900 f)))
(setf data1 '(900 f))