A closed interval is an interval which has both a maximum and a minimum element. Closed intervals are denoted by where is the minimum and is the maximum. In the interval , is also the infimum (greatest lower bound) and is also the supremum (least upper bound). Alternatively, a closed interval is the set of all such that satisfies both of the inequalities and .
Every closed interval is a closed set.
For any real number , the set containing only is a closed interval.
This article is a stub. Help us out by.