for (i = 0;j < data[3]->nbrSolutions;i++) {
  for (j = 0;j < data[2]->nbrSolutions;j++) {
      for (k = 0;j < data[1]->nbrSolutions;k++) {
          for (l = 0;j < data[0]->nbrSolutions;l++) {
              add_new(data[3]->solutions[i]
                ,data[2]->solutions[j]
                ,data[1]->solutions[k]
                ,data[0]->solutions[l]
                );
           }
       }
    }
}