deletions | additions       diff --git a/header.tex b/header.tex  index 1c87a45..07771c8 100644  --- a/header.tex  +++ b/header.tex 
...
\newcommand{\adgrad}{\nabla_{\mathrm{\!ad}}}  \newcommand{\mugrad}{\nabla_{\!\mu}}  \newcommand{\P}{\mathrm{P}}  \newcommand{\T}{\mathrm{T}}  \newcommand{\cp}{c_{\mathrm{P}}}  \newcommand{\hp}{H_{\mathrm{P}}}  % macros for naming codes, plus shortcuts for some common ones