docs: def unit_tophat_ee (x):
      """Tophat function on the unit interval, left-exclusive and right-exclusive.
      Returns 1 if 0 < x < 1, 0 otherwise.
  
      """
      x = np.asarray (x)
      x1 = np.atleast_1d (x)
      r = ((0 < x1) & (x1 < 1)).astype (x.dtype)
      if x.ndim == 0:
          return np.asscalar (r)
      return r