# how to put symbol on top of tensor product

How do I put a $\frown$ right on top of $\otimes$? I tried \stackrel but it leaves too much space between symbols.

• Welcome to SE. Please show, how you try so far ... Mar 26, 2016 at 3:34

Here's a possibility:

\documentclass{article}
\usepackage{amsmath}

\makeatletter
\DeclareRobustCommand\frownotimes{\mathbin{\mathpalette\frown@otimes\relax}}
\newcommand{\frown@otimes}[2]{%
\vbox{
\ialign{##\cr
\hidewidth$\m@th#1{}_\frown$\kern-\scriptspace\hidewidth\cr
\noalign{\nointerlineskip\kern-1pt}
$\m@th#1\otimes$\cr
}%
}%
}
\makeatother

\begin{document}

$A\frownotimes B_{x\frownotimes y}$

\end{document}

• Very nice. Exactly what I wanted. Mar 26, 2016 at 4:18
• Where does \hidewidth come from (amsmath )? Mar 26, 2016 at 18:53
• @daleif Plain TeX; it's essentially \hskip-1000pt plus 1fill Mar 26, 2016 at 19:06
\documentclass{article}
\usepackage{stackengine,scalerel}
\def\frownotimes{\mathbin{\ThisStyle{\ensurestackMath{\stackengine{-1.4\LMpt}{%
\SavedStyle\otimes}{\mkern1mu\SavedStyle_\frown}{O}{c}{F}{T}{S}}}}}
\begin{document}
$A \frownotimes B_{x \frownotimes y}$
\end{document}