EXTENS                                                                 Page 1

Line Stmt Level
   1    1    0	program extens;
   2    1    0	{ this program does not demonstractte file I/O since that is }
   3    1    0	{ demonstrated in the fileio routine			   }
   4    1    0	
   5    1    0	const tabtop = 52;
   6    1    1	      tabtopp1 = tabtop+1;	{ notice expression of constants }
   7    1    1	{ use this type to show i/o of enumeration types }
   8    1    1	
   9    1    1	type color = ( red, yellow, blue, green, orange, violet );
  10    1    1	     anstyp = string 20;
  11    1    1	
  12    1    1	var  a,b: color;
  13    1    1	     answer: anstyp;
  14    1    1	
  15    1    1	procedure systemok; external;  { external routine to check the system }
  16    1    1	
  17    1    1	begin
  18    1    1	    systemok;		{ verify the system }
  19    2    1	    repeat
  20    3    2		write( 'Enter a color (red, yellow, blue, green, orange, violet): ' );
  21    4    2		readln( a );
  22    5    2		{ show a case statement with an else clause }
  23    5    2		case a of
  24    6    2		    red, yellow, blue: writeln( a:1, ' is a primary color' );
  25    7    2		    orange: writeln( 'orange is made from yellow and red' );
  26    8    2		    violet: writeln( 'violet is made from blue and red' );
  27    9    2		    else:  writeln( 'green is made from blue and yellow' );
  28   10    2		    end;
  29   10    2		write( 'Again? ' );
  30   11    2		readln( answer );
  31   12    2	    until answer = 'NO';
  32   13    1	end.