A set (of numbers) bounded by two elements - the endpoints or bounds. The interval may include or exclude either endpoint, leading to four possibilities:

 closed                   [a, b]  a <= x <= b
 open                     (a, b)  a < x < b
 left-open, right-closed  (a, b]  a < x <=b
 left-closed, right-open  [a, b)  a <= x < b

Intervals are typically defined on real numbers but may also be defined on integers or any other type that has an partial order.

Last updated: 2019-08-31

Nearby terms:


Try this search on Wikipedia, Wiktionary, Google, OneLook.