List Access Functions
There are easy rules for the access functions using the parenthesized representation of lists:
first returns the first thing in a list. A thing is:
(first '(a b c)) -> a (first '((a b) c)) -> (a b)
rest returns the rest of a list after the first thing. Simply move the left parenthesis to the right past the first thing.
(rest '(a b c)) -> (b c) (rest '((a b) c)) -> (c) (rest (rest '((a b) c))) -> () = null