Formula_5973

\[\begin{gathered}{\left[N_{i}, N_{j}\right]=i \varepsilon_{i j k} N_{k},} \\{\left[N_{i}^{+}, N_{j}^{+}\right]=i \varepsilon_{i j k} N_{k}^{+}, \quad\left[N_{i}, N_{j}^{+}\right]=0 .}\end{gathered}\]