namespace Particle {
    newtype Particle = (x : Int, y : Int, z : Int);

    function addParticles(a : Particle, b : Particle) : Particle {
        let (x1, y1, z1) = a!;
        let (x2, y2, z2) = b!;
        return Particle(x1 + x2, y1 + y2, z1 + z2);
    }
}
