\left|\left(\left(\tan^{-1}_* \frac{\mathsf{expm1}\left(\left(\sin \left(\mathsf{expm1}\left(a\right)\right)\right)\right)}{\tan^{-1} a}\right) \bmod a\right)\right|double f(double a) {
double r8010 = a;
double r8011 = expm1(r8010);
double r8012 = sin(r8011);
double r8013 = expm1(r8012);
double r8014 = atan(r8010);
double r8015 = atan2(r8013, r8014);
double r8016 = fmod(r8015, r8010);
double r8017 = fabs(r8016);
return r8017;
}