code: def _erfc_asymp(x):
      # Asymptotic expansion assuming x >= 9
      x2 = x * x
      v = exp(-x2) / x * 0.56418958354775628695
      r = t = 0.5 / x2
      s = 1.0
      for n in range(1, 22, 4):
          s -= t
          t *= r * (n + 2)
          s += t
          t *= r * (n + 4)
          if abs(t) < 1e-17:
              break
      return s * v
  
imports: import operator
  import math
  import cmath
label_desc: Use image node_id 22 for calling a global function with example usage: _erfc_asymp(x) and returns: unknown