p_gamma            53 missing/erf.c      if (x < 1 + a) return 1 - p_gamma(a, x, loggamma_a);
p_gamma            76 missing/erf.c      if (x >= 0) return   p_gamma(0.5, x * x, LOG_PI_OVER_2);
p_gamma            77 missing/erf.c      else        return - p_gamma(0.5, x * x, LOG_PI_OVER_2);
p_gamma            87 missing/erf.c      else        return  1 + p_gamma(0.5, x * x, LOG_PI_OVER_2);