type Vec2 = (float, float)

fn add(a: Vec2, b: Vec2) -> Vec2 {
    (a[0] + b[0], a[1] + b[1])
}

fn sub(a: Vec2, b: Vec2) -> Vec2 {
    (a[0] - b[0], a[1] - b[1])
}

fn dot(a: Vec2, b: Vec2) -> float {
    a[0]*b[0] + a[1]*b[1]
}

u := (0.0, 1.0)
v := (2.0, 3.0)

println(add(u, v))
println(sub(u, v))
println(dot(u, v))