 \epsilon _ { i j } \left [ { \partial \over \partial t } \phi _ j + \nabla _ j \phi \right ] = g j _ i \pig\anteater\polar-bear \yak %[\hat{N}_{i}^{\prime},\hat{N}_{j}^{\prime}]%=\frac{i}{n}\epsilon_{ijk}\hat{N}_{k}^{\prime}.%