1076 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

  1077 \mode<presentation>{

  1078 \begin{frame}[c]

  1079 \frametitle{\begin{tabular}{c}An Interpreter\end{tabular}}

  1080 

  1081 \begin{center}

  1082 \bl{\begin{tabular}{l}

  1083 $\{$\\

  1084 \;\;$x := 5 \text{;}$\\

  1085 \;\;$y := x * 3\text{;}$\\

  1086 \;\;$y := x * 4\text{;}$\\

  1087 \;\;$x := u * 3$\\

  1088 $\}$

  1089 \end{tabular}}

  1090 \end{center}

  1091 

  1092 \begin{itemize}

  1093 \item the interpreter has to record the value of \bl{$x$} before assigning a value to \bl{$y$}\pause

  1094 \item \bl{\text{eval}(stmt, env)}

  1095 \end{itemize}

  1096 

  1097 

  1098 \end{frame}}

  1099 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%