Definition 18.7.2 (h-interval).label A h-interval is an interval of the form $(a, b] \subset \real$ where $-\infty < a \le b < \infty$.
Definition 18.7.2 (h-interval).label A h-interval is an interval of the form $(a, b] \subset \real$ where $-\infty < a \le b < \infty$.