\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 r8006 = a;
double r8007 = expm1(r8006);
double r8008 = sin(r8007);
double r8009 = expm1(r8008);
double r8010 = atan(r8006);
double r8011 = atan2(r8009, r8010);
double r8012 = fmod(r8011, r8006);
double r8013 = fabs(r8012);
return r8013;
}