def circle(pts):
     return dcircle(pts, 0, 0, 1)
 def circle_with_a_hole(pts):
     return ddiff(dcircle(pts, 0, 0, 1), dcircle(pts, 0.5, 0, 0.4))
 def circle_with_a_hole(pts):
     return ddiff(dcircle(pts, 0, 0, 1), dcircle(pts, 0.5, 0, 0.4))
 def circle(pts):
     return dcircle(pts, 0, 0, 1)