An interval in which one endpoint is included but not the other. A half-closed interval is denoted or and is also called a half-open interval. The non-standard notation and is sometimes also used.
Half-Closed Interval
See also
Closed Interval, Interval, Open IntervalExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Half-Closed Interval." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Half-ClosedInterval.html