DECLARE EXTERNAL PICTURE gasket
LET n=7
DRAW gasket(n)
END
EXTERNAL PICTURE gasket(n)
IF n=0 THEN
   PLOT LINES: 0,0;  1,0
ELSE
   DRAW gasket(n-1) WITH SCALE(1,-1)*SCALE(1/2)*ROTATE(PI/3) 
   DRAW gasket(n-1) WITH SCALE(1/2)*SHIFT(1/4, SQR(3)/4)
   DRAW gasket(n-1) WITH SCALE(1,-1)*SCALE(1/2)*ROTATE(-PI/3)*SHIFT(3/4,SQR(3)/4)
END IF
END PICTURE
