The (m, n) representation is, however, unitary when restricted to the rotation subgroup SO(3), but these representations are not irreducible as representations of SO(3). A Clebsch–Gordan decomposition can be applied showing that an (m, n) representation have SO(3) -invariant subspaces of highest weight (spin) m + n, m + n − 1,..., | m − n |, where each possible highest weight (spin) occurs exactly once. A weight subspace of highest weight (spin) j is (2 j + 1) -dimensional. So for example, the (⁠ 1 / 2 ⁠, ⁠ 1 / 2 ⁠) representation has spin 1 and spin 0 subspaces of dimension 3 and 1 respectively.