On Text (over/under - end

\def\overset#1#2{{%
       \HCode{<.msup limits base .>}%
         #2%
         <.msup limits script super .>#1%
         <.close limits sup .>%
}}
\def\underset#1#2{{%
       \HCode{<.msub limits base .>}%
         #2%
         <.msub limits script sub .>#1%
         <.close limits sub .>%
}}

-_-_-

\def\sideset#1#2#3{{\Tg<mrow class="sideset"\Hnewline
>{\HCode{}}#1{\HCode{}#3}#2\Tg</mrow>}}

-_-_-