typedef submodel_vector_type::iterator submodel_vector_iterator;
submodel_vector_type submodels;
submodel_vector_type subsubmodels;
submodel_vector_iterator submodel_iterator, subsubmodel_iterator;
typedef submodel_vector_type::iterator submodel_vector_iterator;
submodel_vector_type submodels;
submodel_vector_type subsubmodels;
submodel_vector_iterator submodel_iterator, subsubmodel_iterator;