(v6 x y) | (v13 x y)
(+ (+ x y) (v6 x y)) | (+ (+ x y) (v13 x y))
(v5 x y) | (v12 x y)
(+ (v5 x y) (+ x y)) | (+ (v12 x y) (+ x y))
(v4 x y) | (v11 x y)
(+ (v4 x y) (+ x y)) | (+ (v11 x y) (+ x y))
(v3 x y) | (v10 x y)
(+ (v3 x y) (+ x y)) | (+ (v10 x y) (+ x y))
(v2 x y) | (v9 x y)
(+ (v2 x y) (+ x y)) | (+ (v9 x y) (+ x y))
