deletions | additions       diff --git a/header.tex b/header.tex  index 8a820c8..5cf301e 100644  --- a/header.tex  +++ b/header.tex 
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\newcommand {\vecdot}[2]{\vec{#1} \cdot \vec{#2}}  \newcommand {\hatDvec}[2]{\hat{#1} \cdot \vec{#2}}  \newcommand {\vecXvec}[2]{\vec{#1} \times \vec{#2}}  \newcommand {\hatXvec}[2]{\hat{#1} \times \vec{#2}} @string{pr = {Phys. Rev.}} %{Physical Review}   @string{prd = {Phys. Rev. D}} %{Physical Review D}