# redefine theorem environment with beamer

beamer seems to define theorem-environments such as definition, but i want to be able to define them myself. In particular I want to use thmtools.

\documentclass{beamer}
\usetheme{Singapore}

\usepackage{amsmath}
\usepackage{mathtools}
\usepackage{thmtools}
\usepackage[english]{babel}

\theoremstyle{definition}
\declaretheorem[style=definition]{definition}

\begin{document}
\title{thmtools + beamer}
\date{\today}
\begin{frame}[plain]
\titlepage
\end{frame}

\end{document}

Compiling this yields

! LaTeX Error: Command \definition already defined.

but I could not find anything like a \redeclaretheorem command.

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possible duplicate of Redefine block template for Beamer theorem-like environment –  Paul Gaborit Oct 8 '12 at 14:12