Positioning dot before text in math mode

Question

I only know of \dot, \cdot. How do I get the dot to appear in the top left position of the alphabet?

The following helps, to have a dot after the t.

$t^.$

Answer 1

Is this what you want?

\documentclass{standalone}
\begin{document}
if $s\in t^\bullet\setminus{}^\bullet t$
\end{document}