Math — Divergence & Curl

\nabla\cdot\mathbf{F} = \frac{\partial F_x}{\partial x} + \frac{\partial F_y}{\partial y} + \frac{\partial F_z}{\partial z}

\nabla\times\mathbf{F}

\nabla\cdot(\nabla\times\mathbf{F}) = 0

\nabla\times(\nabla f) = \mathbf{0}