code: def _erfc_mid(x):
      # Rational approximation assuming 0 <= x <= 9
      return (
          exp(-x * x)
          * _polyval(_erfc_coeff_P, x)
          / _polyval(_erfc_coeff_Q, x)
      )
  
imports: import operator
  import math
  import cmath
label_desc: Use image node_id 21 for calling a global function with example usage: _erfc_mid(x) and returns: unknown