func p<T, U>(g: T -> U, h: (UInt, U, T) -> U) -> ((UInt, T) -> U) {

    var fx: ((UInt, T) -> U)!
    func f(y: UInt, x: T) -> U {
        if y == 0 {
            return g(x)
        }
        else {
            return h(y-1, fx(y-1, x), x)
        }
    }
    fx = f

    return f
}