\begin{frame} \frametitle{Association to the Left} \begin{block}{Association to the Left} A term $t_1 t_2 t_3 \ldots t_n$ restores to $((\ldots ((t_1 t_2) t_3) \ldots ) t_n)$ \end{block} \pause \begin{itemize} \item $xz(yz)$ restores to $(xz)(yz)$\\ not to $x(z(yz))$ \pause \item $Kxy$ restores to $(Kx)y$\\ not $K(xy)$ \pause \item Not all bracket pairs can be dropped:\\ $xzyz$ is when restored $((xz)y)z$\\ quite different from $xz(yz)$ \pause \item Note that the term $SIx$ does not contain a redex $Ix$. \end{itemize} \end{frame}