For questions about the Sorgenfrey line ($\mathbb{R}$ with the lower limit topology) and closely related spaces.
The Sorgenfrey line is obtained by giving $\mathbb{R}$ the lower limit topology, i.e., the topology generated by the family of all half-open intervals of the form $[a,b)$ for $a < b$.
It is a standard counterexample in general topology, and was the first example of a paracompact space whose square (called the Sorgenfrey plane) is not paracompact.
This tag is meant for questions particularly about the Sorgenfrey line, and closely related space, such as it's square.
