%
% Standard topological operations.
%
+\ifx\havemjotopology\undefined
+\def\havemjotopology{1}
-% Needed for \operatorname.
-\usepackage{amsopn}
-\input{mjo-common}
+\ifx\operatorname\undefined
+ \usepackage{amsopn}
+\fi
+
+\input{mjo-common} % for \of, at least
% The ``interior of'' operator.
\newcommand*{\interior}[1]{ \operatorname{int}\of{{#1}} }
% The ``closure of'' operator.
-\newcommand*{\closure}[1]{ \overline{{#1}} }
+\newcommand*{\closure}[1]{ \operatorname{cl}\of{{#1}} }
% And the ``boundary of'' operator.
\newcommand*{\boundary}[1]{ \operatorname{bdy}\of{{#1}} }
+
+
+\fi