An introduction to the extended real line, with its total order (extending the total order on the real line), and a metric (induced, via a suitable bijection, by the usual metric on [-1,1]).
Brief discussion of convergence in the extended real line.
Please note that at time 5:33, I intended to say 'is strictly
greater than the least upper bound.'
For more information and links to further resources, see my blog pagehttps://explainingmaths.wordpress.com/measure-theory/ 