% \subsubsection{Abstract}
% \DescribeEnv{abstract}{Every activity should include a short abstract.}
%    \begin{macrocode}
%<*classXimera>
\let\abstract\relax
\let\endabstract\relax
% Use of environ package, may want to find a better way.
\NewEnviron{abstract}{\protected@xdef\theabstract{\BODY}}
%</classXimera>
%    \end{macrocode}
% The abstract has been stored in |\theabstract| and should be emitted
% as a div, but confusingly I guess |<div class="abstract">| is
% defined somewhere deeper inside tex4ht, so the code below is
% probably unnecessary.