ext_integrator(n_int, eps, S-1);
ext_integrator(n_int, eps, S-1, 0);
void ext_integrator(int * const n_int, const double tau, const int S) {  int i,j;  double eps0, eps;  if(S == g_nr_of_psf) {    /* initialize the counter for the inverter */    count00=0; count01=0; count10=0; count11=0; count20=0; count21=0;  }  eps = tau/((double)n_int[S]);  if(S == 1) {    eps0 = eps/((double)n_int[0]);    update_fermion_momenta(0.5 * eps, S-1);    gauge_momenta(0.5 * eps0);    for(j = 0; j < n_int[S]; j++) {      for(i = 0; i < n_int[0]; i++) {	update_gauge(eps0); 	gauge_momenta(eps0);      }      update_fermion_momenta(eps, S-1);    }    for(i = 1; i < n_int[0]; i++) {      update_gauge(eps0);       gauge_momenta(eps0);    }    update_gauge(eps0);     gauge_momenta(0.5 * eps0);    update_fermion_momenta(0.5 * eps, S-1);  }  else {    update_fermion_momenta(0.5 * eps, S-1);    for(i = 1; i < n_int[S]; i++){      ext_integrator(n_int, eps, S-1);      update_fermion_momenta(eps, S-1);    }    ext_integrator(n_int, eps, S-1);    update_fermion_momenta(0.5 * eps, S-1);  }}