):
    def func(*args,**kwds):
      fx = f(*args,**kwds)
      return a*fx**2 + b*fx + c
    return func
  return dec
zs    def func(*args, **kwds):
      x = f(*args, **kwds)
      if inverted[0]: x = -x
      return a*x**2 + b*x + c
)