((% x. x + 2) 1)
((% x. x + 2) y)
((% f. (f 3)) (% x. x + 2))
(((% x. (% y. x + y)) y) 3)
((% x. (% y. x + y)) y)
(define k 3)
(define double (% x. x + x))
(double k)

(define I (% x. x))
(I x)
(I y)

(define K (% x. (% y. x)))
((K x) y)
((K x) x)
((K 3) y)

(define S (% x. (%y. (%z. ((x z) (y z))))))

(define I1 ((S K) K))
(I1 x)
(I1 y)

