define nil ()
define (pair (?x) (?y)) ((?x ?y))
define (first (?x ?y)) (?x)
define (second (?x ?y)) (?y)

define (quote ?x) (quote ?x)
define (if ?c ?t else ?f) (if/else ?c quote ?t quote ?f)
define (if/else (true) quote (?t) quote (?f)) (?t)
define (if/else (false) quote (?t) quote (?f)) (?f)

define (hello) (bye)

pair (pair (foo) (nil)) (baz)