(> 4 3)
(> 3 4)
(< 3 4)
(< 4 3)
(= 4 4)
(= 3 4)
(< km mile)
(< mile km)
(< (* 2 km) mile)
(< (* 3 (/ mile hour)) (/ meter second))

(if (> 4 3) 5 6)
(if (> 3 4) 5 6)
(if (< (* 3 (/ mile hour)) (/ meter second)) (* 15 ounce) pound)
(if (> (* 3 (/ mile hour)) (/ meter second)) (* 15 ounce) pound)

(/ (if (> 4 3) 5 6) 5)
(* (if (> 3 4) 5 6) 5)
(/ (if (< (* 3 (/ mile hour)) (/ meter second)) (* 15 ounce) pound) kg)
(/ (if (> (* 3 (/ mile hour)) (/ meter second)) (* 15 ounce) pound) kg)
(if (> 4 3) (if (< 5 6) 7 8) (if (< 6 5)9 10))
(if (< 4 3) (if (< 5 6) 7 8) (if (< 6 5)9 10))
(* 4 (if (> 4 3) (if (< 5 6) 7 8) (if (< 6 5)9 10)))
(/ (if (< 4 3) (if (< 5 6) 7 8) (if (< 6 5)9 10)) 5)

(let () 5)
(let () (* 3 4))
(let () (/ 60 5))

(let (($x 5)) $x)
(let (($x 5)) (* $x meter))
(let (($x 5)) (* $x $x))
(let (($x 5) ($y 6) ($z 35)) (/ (* $y $z) $x))

(let (($x (* 2 3))) $x)
(let (($x (* 2 3))) (* $x meter))
(let (($x (* 2 3))) (* $x $x))
(let (($x (* 2 3)) ($y (* 4 5)) ($z (* 6 7))) (/ (* $y $z) $x))

(let* () 5)
(let* () (* 3 4))
(let* () (/ 60 5))

(let* (($x 5)) $x)
(let* (($x 5)) (* $x meter))
(let* (($x 5)) (* $x $x))
(let* (($x 5) ($y 6) ($z 35)) (/ (* $y $z) $x))

(let* (($x (* 2 3))) $x)
(let* (($x (* 2 3))) (* $x meter))
(let* (($x (* 2 3))) (* $x $x))
(let* (($x (* 2 3)) ($y (* 4 5)) ($z (* 6 7))) (/ (* $y $z) $x))
(let* (($x 5) ($y $x)) (* $y $x))
(let* (($x 5) ($y (* 6 $x))) (* $y $x))

(let (($f (lambda ($x) $x))) ($f 5))
(let (($f (lambda ($x) $x))) ($f (* 5 meter)))
(let (($f (lambda ($x) (* meter $x)))) ($f 5))
(let (($f (lambda ($x) (* meter $x)))) ($f (* 6 7)))
(let (($f (lambda ($x) (* $x $x)))) ($f 5))
(let (($f (lambda ($x $y) (* $x $y)))) ($f 6 7))
(let (($f (lambda ($x $y) (* $x $y))) ($g (lambda ($z) (* $z $z)))) ($f 6 ($g 3)))

(let* (($f (lambda ($x $y) (* $x $y))) ($g (lambda ($z) ($f $z $z)))) ($g 3))
(let* (($f (lambda ($x $y) (* $x $y))) ($g (lambda ($z) ($f $z $z)))) ($f ($g 3) ($g 4)))
(let* (($f (lambda ($x $y) (* $x $y))) ($f (lambda ($z) ($f $z $z)))) ($f 3))

(define $a 6)
(* 7 $a)
(let (($a 99)) (* 7 $a))
(* 7 $a)
(let (($b 99)) (* $a $b))
(let (($h (lambda ($x) (* 7 $x)))) ($h $a))
(let (($h (lambda ($x) (* $a $x)))) ($h 7))
(let (($a 99) ($h (lambda ($x) (* $a $x)))) ($h 7))

(define $cube (lambda ($x) (* $x $x $x)))
($cube 2)
(* ($cube 2) ($cube 3))
($cube ($cube 2))
($cube (let (($cube (lambda ($x) (* $x $x)))) ($cube 2)))

(define $double (lambda ($f) (lambda ($x) ($f ($f $x)))))
(define $g ($double $cube))
($g 3)

(define $h (lambda ($x) (if (< $x 1) $x (* $x ($h (/ $x 2))))))
($h 2)
(* 8 ($h 3))

(define $d ($double $h))
($d 8)