deletions | additions       diff --git a/kinematics.tex b/kinematics.tex  index 8fbefd8..3e3eca4 100644  --- a/kinematics.tex  +++ b/kinematics.tex 
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\begin{equation}  \begin{split}  \mid \mathbf{p} \mid^2 &=p^2 +  E^2 + p^2  \\ &= m^2 \end{split}  \end{equation}