\def\havemjotopology{1}
-% Needed for \operatorname.
-\usepackage{amsopn}
+\ifx\operatorname\undefined
+ \usepackage{amsopn}
+\fi
-\input{mjo-common}
+\input{mjo-common} % for \of, at least
% The ``interior of'' operator.
\newcommand*{\interior}[1]{ \operatorname{int}\of{{#1}} }