PROTODIR_LIST
if ((second_list.type == PROTODIR_LIST) &&
(first_list.type != PROTODIR_LIST)) {
if (!e && (first_list.type == PROTODIR_LIST) &&
(second_list.type != PROTODIR_LIST)) {
if (!e && (first_list.type != PROTODIR_LIST) &&
(second_list.type == PROTODIR_LIST)) {
list->type = PROTODIR_LIST;