11/129
\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}