447 

   447 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   

   448 

   448 

   449 % {

   450 % \setbeamercolor{background canvas}{bg=cream}

   451 % \begin{frame}[c]

   452 % \small

   453 

   454 % \begin{lstlisting}[language=Scala,numbers=none]

   455 % enum Rexp {

   456 %   case ZERO

   457 %   case ONE

   458 %   case CHAR(c: Char)

   459 %   case ALT(r1: Rexp, r2: Rexp)

   460 %   case SEQ(r1: Rexp, r2: Rexp)

   461 %   case STAR(r: Rexp)

   462 % }

   463 % \end{lstlisting}

   464 

   465 % \begin{lstlisting}[language=Scala,numbers=none]

   466 % enum Val {

   467 %   case Empty

   468 %   case Chr(c: Char)

   469 %   case Sequ(v1: Val, v2: Val)

   470 %   case Left(v: Val)

   471 %   case Right(v: Val)

   472 %   case Stars(vs: List[Val])

   473 % }

   474 % \end{lstlisting}

   475 

   476 % \end{frame}

   477 % }