begin 
   procedure digit(I);
     value I;
     integer I;
   begin 
     if I = 0 then writetex(30, `0');
     if I = 1 then writetex(30, `1');
     if I = 2 then writetex(30, `2');
     if I = 3 then writetex(30, `3');
     if I = 4 then writetex(30, `4');
     if I = 5 then writetex(30, `5');
     if I = 6 then writetex(30, `6');
     if I = 7 then writetex(30, `7');
     if I = 8 then writetex(30, `8');
     if I = 9 then writetex(30, `9');
   end digit;

   procedure wrnum(i);
      value i;
      integer i;
    begin 
      if i < 0 then begin;
        writetex(30, `-');
        i := -i;
      end;
      if i > 10 then begin;
        wrnum(i / 10);
        i := i - ((i / 10) * 10);
      end;
      digit(i);
   end wrnum;

   open(30);
   writetex(30, `Hello World');
   wrnum(42);
   digit(6);
   close(30)
end