flood 0,0
SET AREA COLOR 0
FOR k=0 TO 5
   DRAW a(k)
   gsave STR$(k)&".gif"
NEXT k
END
EXTERNAL PICTURE a(n)
IF n=0 THEN
ELSEIF n=1 THEN
   PLOT AREA:1/3,1/3;2/3,1/3;2/3,2/3;1/3,2/3
ELSE
   FOR i=0 TO 2
      FOR j=0 TO 2
         DRAW a(n-1) WITH SCALE(1/3)*SHIFT(2*i/3,2*j/3)
      NEXT j
   NEXT i
END IF
END PICTURE