memset(&st->avlname, 0, sizeof(avl));
memset(&st->variables_root_index, 0, sizeof(avl_tree_lock));
memset(&st->dimensions_index, 0, sizeof(avl_tree_lock));
memset(&st->avlname, 0, sizeof(avl));
memset(&st->variables_root_index, 0, sizeof(avl_tree_lock));
memset(&st->dimensions_index, 0, sizeof(avl_tree_lock));