The classical Littlewood-Richardson coefficients C(lambda,mu,nu) carry a natural $S_3$ symmetry via permutation of the indices. Our "carton rule" for computing these numbers transparently and uniformly explains these six symmetries; previously formulated Littlewood-Richardson rules manifest at most three of the six.

经典的Littlewood-Richardson系数C(lambda，Mu，Nu)带有一个 通过指数排列实现的自然$S_3$对称性。我们的“纸箱规则” 透明而统一地计算这些数字解释了这六个 对称性；先前制定的Littlewood-Richardson规则至多可见 六个中的三个。