$$
\newcommand{\C}{{\mathbb{{C}}}}
\newcommand{\R}{{\mathbb{{R}}}}
\newcommand{\Q}{{\mathbb{{Q}}}}
\newcommand{\Z}{{\mathbb{{Z}}}}
\newcommand{\N}{{\mathbb{{N}}}}
\newcommand{\uu}[1]{{\boldsymbol{{#1}}}}
\newcommand{\uuuu}[1]{{\symbb{{#1}}}}
\newcommand{\uv}[1]{{\underline{{#1}}}}
\newcommand{\ve}[1]{{\uv{{e}}_{{#1}}}}
\newcommand{\x}{{\uv{{x}}}}
\newcommand{\n}{{\uv{{n}}}}
\newcommand{\eps}{{\uu{{\varepsilon}}}}
\newcommand{\E}{{\uu{{E}}}}
\newcommand{\sig}{{\uu{{\sigma}}}}
\newcommand{\Sig}{{\uu{{\Sigma}}}}
\newcommand{\cod}{{\uv{{\symscr{b}}}}}
\newcommand{\trans}[1]{{{}^{t}{#1}}}
\newcommand{\sotimes}{{\stackrel{s}{\otimes}}}
\newcommand{\sboxtimes}{\stackrel{s}{\boxtimes}}
\newcommand{\norm}[1]{{\lVert{{#1}}\rVert}}
\newcommand{\ud}{{\,\mathrm{d}}}
\DeclareMathOperator{\arcosh}{arcosh}
\DeclareMathOperator{\divz}{div}
\DeclareMathOperator{\divu}{\uv{div}}
\DeclareMathOperator{\hess}{hess}
\DeclareMathOperator{\gradu}{\uv{grad}}
\DeclareMathOperator{\graduu}{\uu{grad}}
\DeclareMathOperator{\Mat}{Mat}
\DeclareMathOperator{\tr}{tr}
\DeclareMathOperator{\ISO}{ISO}
\newcommand{\jump}[1]{[\hspace*{-.15em}[\hspace*{.1em}{#1}%
\hspace*{.1em}]\hspace*{-.15em}]}
$$
\(\,\)