Editing Counterexamples in Topology (section)

==Notation==
Several of the [[naming convention]]s in this book differ from more accepted modern conventions, particularly with respect to the [[separation axiom]]s. The authors use the terms T<sub>3</sub>, T<sub>4</sub>, and T<sub>5</sub> to refer to [[regular space|regular]], [[normal space|normal]], and [[completely normal space|completely normal]]. They also refer to  [[completely Hausdorff space|completely Hausdorff]] as [[Urysohn and completely Hausdorff spaces|Urysohn]]. This was a result of the different historical development of metrization theory and [[general topology]]; see [[History of the separation axioms]] for more.

The [[long line (topology)|long line]] in example 45 is what most topologists nowadays would call the 'closed long ray'.