Definition:Real Interval/Closed

Definition
Let $a, b \in \R$. The closed (real) interval from $a$ to $b$ is defined as:


 * $\left [{a \,.\,.\, b} \right] = \left\{{x \in \R: a \le x \le b}\right\}$

Also known as
Such an interval can also be referred to as compact.

Some sources do not explicitly define an open interval, and merely to a closed real interval as an interval. Such imprecise practice is usually discouraged.

Also see

 * Definition:Open Real Interval
 * Definition:Half-Open Real Interval
 * Definition:Unbounded Open Real Interval
 * Definition:Unbounded Closed Real Interval