let
	id    = λx.x
	zero  = λf x. x
	one   = λf x. f x
	two   = λf x. f (f x)
	three = λf x. f (f (f x))
	four  = λf x. f (f (f (f x)))
	five  = λf x. f (f (f (f (f x))))
	six   = λf x. f (f (f (f (f (f x)))))
	seven = λf x. f (f (f (f (f (f (f x))))))
	eight = λf x. f (f (f (f (f (f (f (f x)))))))
	nine  = λf x. f (f (f (f (f (f (f (f (f x))))))))
	ten   = λf x. f (f (f (f (f (f (f (f (f (f x)))))))))
in (λx.x two two id id) four