\Configure{MathClass}{1}{*}{<mo\Hnewline
class="MathClass-op"><BREAK SIZE="small"/>}
{<BREAK SIZE="small"/></mo>}{}
\Configure{MathClass}{2}{*}{<mo\Hnewline
class="MathClass-bin"><BREAK SIZE="small"/>}
{<BREAK SIZE="small"/></mo>}{}
\Configure{MathClass}{3}{*}{<mo\Hnewline
class="MathClass-rel"><BREAK SIZE="small"/>}
{<BREAK SIZE="small"/></mo>}{}
\:CheckOption{mathml-} \if:Option
\Configure{MathClass}{4}{*}{<mo\Hnewline
class="MathClass-open">}
{</mo><BREAK SIZE="small"/>}{}
\Configure{MathClass}{5}{*}{<BREAK SIZE="small"/>%
<mo\Hnewline
class="MathClass-close">}
{</mo>}{}
\else
\Configure{MathClass}{4}{*}{<mfenced><mo\Hnewline
class="MathClass-open">}
{</mo><mrow><BREAK SIZE="small"/>}{}
\Configure{MathClass}{5}{*}{<BREAK SIZE="small"/>%
</mrow><mo\Hnewline
class="MathClass-close">}
{</mo></mfenced>}{}
\fi
-_-_-