public void restrictWith(BDD var) { restrictWith0((BuDDyBDD) var);
public BDD restrictWith(BDD var) { BuDDyBDD c = (BuDDyBDD) var; int b = restrict0(_id, c._id); addRef(b); delRef(_id); if (this != c) { delRef(c._id); c._id = INVALID_BDD; } _id = b; return this;
        public void restrictWith(BDD var) {            restrictWith0((BuDDyBDD) var);        }