Why does smartdiagram replace the Greek letter \xi by a number?

Question

Consider the MWE

\documentclass{beamer}
\usepackage{smartdiagram}
\begin{document}
\begin{frame}[plain]
\smartdiagramanimated[descriptive diagram]{
      {$a$, $\alpha$},
  {$b$,$\beta$},
  {$x$,$\xi$}}
\end{frame}
\end{document}

Instead of the expected Greek letter ξ there is a 3. Why?

Answer 1

This is because \xi is used as an internal loop variable in the smartdiagram package. One way to fix this is

\documentclass{beamer}
\usepackage{smartdiagram}
\let\oldxi\xi
\begin{document}
\begin{frame}[plain]
\smartdiagramanimated[descriptive diagram]{
      {$a$, $\alpha$},
  {$b$,$\beta$},
  {$x$,$\oldxi$}}
\end{frame}
\end{document}

@Claudio: I will be very happy to remove these posts if you feel they are inappropriate. I really love your package(s)!