One forms the set of all Young diagrams that can be obtained from the diagram of shape by removing just one box (which must be at the end both of its row and of its column); the restricted representation then decomposes as a direct sum of the irreducible representations of corresponding to those diagrams, each occurring exactly once in the sum.
One forms the set of all Young diagrams that can be obtained from the diagram of shape by removing just one box (which must be at the end both of its row and of its column); the restricted representation then decomposes as a direct sum of the irreducible representations of corresponding to those diagrams, each occurring exactly once in the sum.