code: def erfc(x):
      """
      erfc of a real number.
      """
      x = float(x)
      if x != x:
          return x
      if x < 0.0:
          if x < -6.0:
              return 2.0
          return 2.0 - erfc(-x)
      if x > 9.0:
          return _erfc_asymp(x)
      if x >= 1.0:
          return _erfc_mid(x)
      return 1.0 - _erf_taylor(x)
  
imports: import operator
  import math
  import cmath
label_desc: Use image node_id 24 for calling a global function with example usage: erfc(x) and returns: unknown, x, unknown, _erfc_asymp, _erfc_mid, int