I would like to simplify $\boldsymbol{\nabla}\cdot\boldsymbol{\sigma}_{brag}$, given by:
taken from this paper. For a magnetic field, $\vec{B}$, of the form $$\vec{B}=(0,b(x,z),B_0),$$ and velocity, $$\vec{u}=(0,u(x,z),0).$$ It seems like too much effort to do this manually, especially since I have almost no knowledge of tensor calculus. Does anyone know how I could get a computer to do this? I have maple but not Mathematica.