deletions | additions       diff --git a/header.tex b/header.tex  index afefe2f..21cd37b 100644  --- a/header.tex  +++ b/header.tex 
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\newcommand{\adgrad}{\nabla_{\mathrm{\!ad}}}  \newcommand{\mugrad}{\nabla_{\!\mu}}  \newcommand{\P}{\mathrm{P}}  \newcommand{\p}{\mathrm{P}}  \newcommand{\T}{T}  \newcommand{\cp}{c_{\mathrm{P}}}  \newcommand{\hp}{H_{\mathrm{P}}}