public boolean compareResult(TruthType with) {
            if (with == TruthType.UNKNOWN)
                return false;
            switch(result) {
            case UNKNOWN:
                return false;
            case TAUTOLOGY:
            case SATISFIABLE:
            case CONTRADICTION:
                return (with == result);
            case NOT_TAUTOLOGY:
                return (with == TruthType.SATISFIABLE ||
                with == TruthType.CONTRADICTION);
            case NOT_CONTRADICTION:
                return (with == TruthType.SATISFIABLE ||
                with == TruthType.TAUTOLOGY);
            }
            return false;
        }