.. only:: html

    :math:`\newcommand{\p}[1]{\frac{\partial }{\partial #1}}`
    :math:`\newcommand{\pp}[2]{\frac{\partial #1}{\partial #2}}`
    :math:`\newcommand{\dd}[2]{\frac{d #1}{d #2}}`
    :math:`\newcommand{\h}{\frac{1}{2}}`