if (!old_left_neighbor || left_rank > Paper_column::get_rank (old_left_neighbor))
right_col->set_object ("left-neighbor", left_col->self_scm ());
}
if (!old_left_neighbor || left_rank > Paper_column::get_rank (old_left_neighbor))
right_col->set_object ("left-neighbor", left_col->self_scm ());
}