\begin{frame} \small \newcommand{\rc}{\tikz[baseline=-2pt]{\node{\includegraphics[width=6mm]% {../graphics/red.jpg}};}} \newcommand{\bc}{\tikz[baseline=-2pt]{\node{\includegraphics[width=6mm]% {../graphics/blue.jpg}};}} \newcommand{\gc}{\tikz[baseline=-2pt]{\node{\includegraphics[width=6mm]% {../graphics/green.jpg}};}} \begin{definition} \smallskip TRS $\RR$ over signature $\FF$ is \alert{string rewrite system} (\alert{SRS}) if $\FF$ consists of unary function symbols \end{definition} \bigskip \begin{example}<2-> \vspace{-1ex} \begin{xalignat*}{2} \alt<3>{\rc\gc}{\rc(\gc(x))} &~\to~ \alt<3>{\bc\bc}{\bc(\bc(x))} & \alt<3>{\gc\rc}{\gc(\rc(x))} &~\to~ \alt<3>{\bc\bc}{\bc(\bc(x))} \\ \alt<3>{\bc\rc}{\bc(\rc(x))} &~\to~ \alt<3>{\gc\gc}{\gc(\gc(x))} & \alt<3>{\rc\bc}{\rc(\bc(x))} &~\to~ \alt<3>{\gc\gc}{\gc(\gc(x))} \\ \alt<3>{\gc\bc}{\gc(\bc(x))} &~\to~ \alt<3>{\rc\rc}{\rc(\rc(x))} & \alt<3>{\bc\gc}{\bc(\gc(x))} &~\to~ \alt<3>{\rc\rc}{\rc(\rc(x))} \end{xalignat*} \end{example} \end{frame}