PICTURE D(n)
   IF n=18 THEN
      PLOT POINTS: 0,0
   ELSE 
      DRAW D(n+1) WITH SCALE(1,-1)*ROTATE(PI/4)*SCALE(1/SQR(2))
      DRAW D(n+1) WITH SHIFT(-1,0)*ROTATE(PI/4)*SCALE(1/sqr(2))*SHIFT(1,0)
   END IF
END PICTURE
SET WINDOW -1/2 , 3/2 , -1 , 1
SET POINT STYLE 1
DRAW D(0)
GSAVE "levycurve.bmp"
WAIT DELAY 1
CLEAR
WAIT DELAY 2
GLOAD "levycurve.bmp"
END