7 #                   9        9                          
  $  
  $  
$    
$    
$   
2    
R    
R    
R    
R 
  
\ 
  
f    
f    x  
R           Y *      
$      Y    4 %  Y    Y        Y    Y    Y    Y    Y    Y    static unsigned long branches = 0;
static unsigned long nestdepth = 0;

void processtoken(long token)
{
   switch( token )
   {
      case IFTOKEN:
         if( conditional nest < (unsigned long)-1 )
         {
            nestdepth <<= 1;
            branches  <<= 1;
            nestdepth |= 1;
            branches  |= evaluateif() ? 1 : 0;
         }
         else
            nestedtoodeeperror();
         break;

      case ELSETOKEN:
         if( nestdepth )
            branches ^= 1;
         else
            elsewithoutiferror();
         break;

      case ENDIFTOKEN:
         if( nestdepth )
         {
            nestdepth >>= 1;
            branches  >>= 1;
         }
         else
            endifwithoutiferror();
         break;

      ... case statements for other commands follow ...

      case SOMECOMMAND:
         if( branches == nestdepth )
         {
            // we are in the true branch of a conditional (or none at all)
            // so we should evaluate this command
            DOSOMECOMMAND();
         }

      ... etceteras ...
   }
}


u .j~N{.jN{.jN{BWN{`> N{`.j?< N{X.j/,jN{x.jN{> N{`BWN{NxN{h ljZ Ph O g ljZ P P/Nz X ljV Ph g ljV P P/Nz X ljV Pp1@  ljZ P1@  ljN P1@  ljJ P1@     9  <                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
 @      
 :F         #  G  H  f  h  {            
  )  X  c  q                  .  /  F  _  j                )  *  B  g  r            0  5  7  8  9                                                                                                                                                                                                                                                    !  3               
               9   9      7  9P     @           <      9       
       ! "                                                                 	#$()GH]^_`"""""<">"?"@"""""""""""# ****3(3)3*3+3,3-3.3U888888:E:F:G:H:::    H H    (FG(    H H    (    d       '                     @                         =/  R    B      H 
-:LaserWriter 
        Times  :FB Letter Gothic Bold        9           ( e ( B    Cool Barbara  Cool Barbara                                                                                                                                                                                                                                                                                                                                                             