deletions | additions       diff --git a/header.tex b/header.tex  index 171fa24..b22e9e8 100644  --- a/header.tex  +++ b/header.tex 
...
%% citecolor=blue, filecolor=blue, menucolor=blue, urlcolor=blue}  %%  \def\k{{\bf k}} %%  \def\ket#1{\vert #1 \rangle} %%  \def\bra#1{\langle #1 \vert} %%  \def\me#1#2#3{\bra{#1} #2 \ket{#3}} %%  \def\olap#1#2{\bra{#1} #2 \rangle} %%  \def\avg#1{\langle #1 \rangle} %%  \DeclareMathOperator{\sgn}{sgn}