# Is there a Latex symbol that combines \top and \bot?

I'd like to have a symbol that is the exact overlap between \top and \bot so that it looks like the roman number "Ⅰ". I have searched a particular symbol, but I found nothing. And overlapping techniques in this and other forums are a little confusing.

Can someone help me?

• One very simple alternative: a similar-looking character in Unicode, which you could use with unicode-math, is U+2336, APL functional symbol I-beam(⌶). The accepted answer is great, though. – Davislor Feb 11 '18 at 21:37

The following code implements \bottop that combines \bot and \top with respecting the current math style:

\documentclass{article}

\makeatletter
\newcommand*{\bottop}{%
\mathpalette\@bottop{}%
}
\newcommand*{\@bottop}[2]{%
% #1: math style
% #2: unused
\rlap{$#1\bot\m@th$}% put \bot to the right without moving the current point
\top
}
\makeatother

\begin{document}
$\bottop \scriptstyle \bottop \scriptscriptstyle \bottop$
\end{document}


From http://tug.ctan.org/info/symbols/comprehensive/symbols-a4.pdf here is a possible implementation:

\documentclass{article}

\def\topbotatom#1{\hbox{\hbox to 0pt{$#1\bot$\hss}$#1\top$}}
\newcommand*{\topbot}{\mathrel{\mathchoice{\topbotatom\displaystyle}
{\topbotatom\textstyle}
{\topbotatom\scriptstyle}
{\topbotatom\scriptscriptstyle}}}
\begin{document}
$\topbot$
\end{document}