C++ Programming/Half open

A range [a,b) or (a,b] is half-open in that it is "open" at one end (doesn't include its limit point) and "closed" at the other (does include its limit point).

$[a,b)$ is defined as $\{x|a\le x<b\}$

These terms have most meaning in a topological space, but are also useful in computer science.