w = x; if (x->tavl_tag[0] == TAVL_THREAD) { x->tavl_tag[0] = TAVL_CHILD; y->tavl_tag[1] = TAVL_THREAD; y->tavl_link[1] = x; } else y->tavl_link[1] = x->tavl_link[0]; x->tavl_link[0] = y; x->tavl_balance = y->tavl_balance = 0;