If this were a finite-dimensional representation, then j 0 would correspond the lowest occurring eigenvalue j (j + 1) of J in the representation, equal to | m − n |, and j 1 would correspond to the highest occurring eigenvalue, equal to m + n. In the infinite-dimensional case, j 0 ≥ 0 retains this meaning, but j 1 does not. For simplicity, it is assumed that a given j occurs at most once in a given representation (this is the case for finite-dimensional representations), and it can be shown that the assumption is possible to avoid (with a slightly more complicated calculation) with the same results.