open gcdt2[Int]

fun plusFn [n: Int]: Int one->one Int {
	{lhs, rhs: Int | rhs = lhs + n}
}

fun plusOp [n: Int]: Commutative {
	{c: Commutative |
		c.fn = {lhs: Int, rhs: (Int one->one Int) | rhs = plusFn[lhs]}
	}
}