code: def _log_erfc(x: float) -> float:
      r"""Computes :math:`log(erfc(x))` with high accuracy for large ``x``.
  
      Helper function used in computation of :math:`log(A_\alpha)`
      for a fractional alpha.
  
      Args:
          x: The input to the function
  
      Returns:
          :math:`log(erfc(x))`
      """
      return math.log(2) + special.log_ndtr(-x * 2**0.5)
  
file_path: opacus/opacus/accountants/analysis/rdp.py
imports: import math
  import warnings
  from typing import List, Tuple, Union
  import numpy
  from scipy import special
label_desc: Use image node_id 6 for calling a global function with example usage: _log_erfc(x) and returns: unknown