1 ;; MISC ESSENTIAL PROCEDURES
10 (cons (proc (car l)) (map proc (cdr l))))))
16 (cons (car l1) (join-lists (cdr l1) l2)))))
18 ; Append an arbitrary number of lists together
23 (if (null? (cdr lists))
25 (join-lists (car lists) (apply append (cdr lists)))))))