[Tex/LaTex] Symbols for symmetric difference

symbols

I have the problem with a symbol for symmetric difference (see http://en.wikipedia.org/wiki/Symmetric_difference). In commonly used is

\triangle
\ominus

But in Polish tradition often is used:

\dot{-}

and I would like to ask if it is possible to make dot be a little bit down to (close to) line (here where is the red dot).

enter image description here

Best Answer

I've shifted the dot down relative to \dot{-}. You may adjust the value of .2\LMex to suit.

EDITED to make it more robust and to achieve a more uniform vertical spacing at the smaller math styles.

\documentclass{article}
\usepackage{stackengine}
\usepackage{scalerel}% IF YOU NEED IT FOR SCRIPTSTYLE MATH
\newcommand\symdif{\ThisStyle{\mathrel{\ensurestackMath{%
  \stackengine{.2\LMex}{\SavedStyle-}{\SavedStyle\dot{}}{U}{c}{F}{F}{L}}}}}
\begin{document}
\( A \symdif B \)
\(\scriptstyle A \symdif B \)
\(\scriptscriptstyle A \symdif B \)
\end{document}

enter image description here