deletions | additions       diff --git a/Summary.tex b/Summary.tex  index 3915a96..fbd18b3 100644  --- a/Summary.tex  +++ b/Summary.tex 
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\partial_x\partial_z & \partial_y\partial_z & \partial_z^2  \end{bmatrix} = \partial_i\partial_j \\ \\  \nabla(\nabla(\nabla \cdot))=\partial_i\partial_j\partial_k \\ ????\\  \\ \nabla^2=  \begin{bmatrix}