public boolean hasUnaryInput() {
		if (left instanceof LvalExpression &&
			    ((LvalExpression) left).hasUnaryInput()) {
			return true;
		}

		if (middle instanceof LvalExpression &&
			    ((LvalExpression) middle).hasUnaryInput()) {
			return true;
		}

		if (right instanceof LvalExpression &&
			    ((LvalExpression) right).hasUnaryInput()) {
			return true;
		}

		return false;
	}