int m = bdd_makenode(LEVEL(r), res, BDDZERO);
int m = makenode_impl(LEVEL(r), res, (ZDD && LOW(r)==HIGH(r))?res:BDDZERO);
    int satone_rec(int r) {        if (ISCONST(r))            return r;        if (ISZERO(LOW(r))) {            int res = satone_rec(HIGH(r));            int m = bdd_makenode(LEVEL(r), BDDZERO, res);            PUSHREF(m);            return m;        } else {            int res = satone_rec(LOW(r));            int m = bdd_makenode(LEVEL(r), res, BDDZERO);            PUSHREF(m);            return m;        }    }