I want to overlay one math symbol on over another -- not on top, but literally overlap. In the language of good-old typewriter (!): Type a character, moving one character back and retype another character at the same spot. Following
\subseteq + \circ as a single symbol ("open subset")
I came up with the following minimal working example:
\documentclass{amsart}
\begin{document}
$
\mathrel{\ooalign{\hss\circ\hss\cr\times}}
$
\end{document}
The symbols overlay the way I want, but I also got repeated error message
Missing $ inserted.
I am confused... Your help and comments are most appreciative!
(note: The example above is just to show what I was trying to do; I know that I can get this particular combo of symbols in other ways)