\(
\usepackage{euler} % must be loaded before fontspec for the whole doc (below); this must be kept for pngmath, however
\usepackage{hyperref}
\usepackage{amsmath}
\usepackage{amsbsy}
%\usepackage{mathabx}
\usepackage{underscore}
\usepackage[all]{xy}
% Metadata of the pdf output
\hypersetup{pdftitle={Yade Documentation}}
\hypersetup{pdfauthor={Smilauer, V., et al.}}
\hypersetup{pdfkeywords={Discrete element method, granular materials, contact law, hydromechanical coupling}}
% symbols
\renewcommand{\mat}{\boldsymbol}
\renewcommand{\vec}{\boldsymbol}
\renewcommand{\tens}{\boldsymbol}
%normalized and locfram here
\def\normalized#1{\widehat{#1}}
\def\locframe#1{\widetilde{#1}}
% timestep
\def\Dt{\Delta t}
\def\Dtcr{\Dt_{\rm cr}}
% algorithm complexity
\def\bigO#1{{\mathcal{O}(#1)}}
% variants for greek symbols
\let\epsilon\varepsilon
\let\theta\vartheta
\let\phi\varphi
% shorthands
\let\sig\sigma
\let\eps\epsilon
% variables at different points of time
\def\prev#1{#1^-}
\def\pprev#1{#1^\ominus}
\def\curr#1{#1^{\circ}}
\def\nnext#1{#1^\oplus}
\def\next#1{#1^+}
% shorthands for geometry
\def\currn{\curr{\vec{n}}}
\def\currC{\curr{\vec{C}}}
\def\uT{\vec{u}_T}
\def\curruT{\curr{\vec{u}}_T}
\def\prevuT{\prev{\vec{u}}_T}
\def\currn{\curr{\vec{n}}}
\def\prevn{\prev{\vec{n}}}
% motion
\def\pprevvel{\pprev{\dot{\vec{u}}}}
\def\nnextvel{\nnext{\dot{\vec{u}}}}
\def\curraccel{\curr{\ddot{\vec{u}}}}
\def\prevpos{\prev{\vec{u}}}
\def\currpos{\curr{\vec{u}}}
\def\nextpos{\next{\vec{u}}}
\def\curraaccel{\curr{\dot{\vec{\omega}}}}
\def\pprevangvel{\pprev{\vec{\omega}}}
\def\nnextangvel{\nnext{\vec{\omega}}}
\def\loccurr#1{\curr{\locframe{#1}}}
\def\numCPU{n_{\rm cpu}}
\DeclareMathOperator{\Align}{Align}
\DeclareMathOperator{\sign}{sgn}
% sorting algorithms
\def\isleq#1{\currelem{#1}\ar@/^/[ll]^{\leq}}
\def\isnleq#1{\currelem{#1}\ar@/^/[ll]^{\not\leq}}
\def\currelem#1{\fbox{$#1$}}
\def\sortSep{||}
\def\sortInv{\hbox{\phantom{||}}}
\def\sortlines#1{\xymatrix@=3pt{#1}}
\def\crossBound{||\mkern-18mu<}
\)
