b = null;
gotoNext();
            public Object next() {                if (b == null) {                    gotoNext();                    if (a == null) {                        throw new NoSuchElementException();                    }                }                lastReturned = b.satOne(v, false);                b.applyWith(lastReturned.id(), BDDFactory.diff);                if (b.isZero()) {                    b.free();                    b = null;                }                return lastReturned;            }