λx. (λy. (λz. (? x) (? z)) (? y))

let
	f(z1,z2,z3) x -> g(h(z1 x, z2), z3)
	g(z1,z2) y -> z1(z2 y)
	h(z1,z2) z -> z1(z2 z)
in f(n1,n2,n3)


λx. (λy. (λz. (n1 x) (n2 z)) (n3 y))