;;; library required
(define l '(a (1 2 (3 4) 5) b))
(memv 'a l)
(memv '(1 2 (3 4) 5) l)
(member '(1 2 (3 4) 5) l)
(define k '((a 1) (b 2) ((((a))) 3)))
(assq 'a k)
(assq '(((a))) k)
(assoc '(((a))) k)