(+ (v4 x y) y) | (+ (v9 x y) y)
(+ (+ (v4 x y) y) x) | (+ (+ (v9 x y) y) x)
(v3 x y) | (v8 x y)
(v2 x y) | (v7 x y)
(v4 x y) | (v9 x y)
