documentclass{beamer}

mode<presentation> {
setbeamercovered{transparent}
useoutertheme{infolines}
usetheme{CambridgeUS}
usecolortheme{dolphin}
}
newtheorem{lema}{Lemma}[section]
begin{document}
begin{frame}

Suppose
\begin{lema}\label{le3}
        Suppose 
\end{lema}

end{frame}
end{document}
`