define member? (lambda (item ls)
   (cond
      ((null? ls) #f)
      (else (or (eq? item (car ls))
      		(member? item (cdr ls)))))))  

(define fview (lambda (item ls)
   (cond
     ((eq? item (car ls)) (cadr ls))
     ((eq? item (cdr ls)) (car ls)))))
                  
  
(define 0degree(lambda (item ls)
  (cond
    ((null? ls) '())
    ((member? item (car ls)) (cons (fview item (car ls)) (list (0degree item (cdr ls))))))))