desc->add_options()("lemethod",boost::program_options::value<std::string>()->default_value("bicgstab")->notifier(&validateLeMethod),"Sets the method used for linear equation solving. Must be in {bicgstab, gmres, qmr}.");
desc->add_options()("lemethod",boost::program_options::value<unsigned>()->default_value(10000),"Sets the maximal number of iterations used for linear equation solving.");
desc->add_options()("precond",boost::program_options::value<std::string>()->default_value("ilu")->notifier(&validatePreconditioner),"Sets the preconditioner used for linear equation solving. Must be in {ilu, diagonal, ildlt}.");
desc->add_options()("restart",boost::program_options::value<unsigned>()->default_value(40),"Sets the number of iterations after which gmres is restarted.");