$$ \require{mathtools} \DeclarePairedDelimiter\ceil{\lceil}{\rceil} \DeclarePairedDelimiter\floor{\lfloor}{\rfloor} \newcommand{\dv}[1]{\frac{\mathrm{d}}{\mathrm{d} #1}} \newcommand{\dvv}[2]{\frac{\mathrm{d} #1}{\mathrm{d} #2}} $$