The following MWE worked in December 2015 based on the archived PDF. But, it does not work today. Any idea?
\documentclass{article}
\usepackage{mathtools}
\DeclarePairedDelimiter{\eceil}{\left\lceil}{\right\rceil}
\begin{document}
$\eceil{\cdot}$
\end{document}
mathtools
is defined withexpl3
. Ok, thanks