Definition:Real Interval/Open

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


 * $\left ({a \,.\,.\, b} \right) := \left\{{x \in \R: a < x < b}\right\}$

Also see

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


 * Open Rectangle, a generalization to higher dimensional spaces