“…Finally, a1−a3 2 is one on a = (1, 1, −1) and vanishes on a = (1, 1, 1) and on a = (1, −1, 1). One can thus see that when I 0 , I 2 and I 3 describe facets of F MN then there are 3M N linearly independent vertices of F 3MN , satisfying equation (15). Moreover, for a = (1, 1, 1), a = (1, −1, 1) and a = (1, 1, −1), the admissible vertices a ⊗ b ⊗ c satisfy I( a, b, c) ≤ 1.…”