# Getting rid of “Package amsmath Warning Unable to redefine math accent \vec.”

When using the llncs style from Springer this conflicts with the definition of \vec from amsmath. Thus this can be overcome with your own def:

\let\origvec\vec
\documentclass{llncs}
\let\springervec\vec
\let\vec\origvec
\usepackage{amsmath}
\begin{document}
$\vec{a}$
$\springervec{a}$
\end{document}