q_gamma            25 missing/erf.c  static double q_gamma(double, double, double);
q_gamma            34 missing/erf.c      if (x >= 1 + a) return 1 - q_gamma(a, x, loggamma_a);
q_gamma            87 missing/erf.c      if (x >= 0) return  q_gamma(0.5, x * x, LOG_PI_OVER_2);