But the article is saying that in Ruby, it's 1.5, right? So it's not the same as here? Or were you referring to the general notion of a midpoint of an infinite range?

Right again. The "also" is a reference to the parent comment.

> In surreal numbers [1], the midpoint between 0 and infinity would be the simplest number greater than 0, which is { 0 | } = 1

Oh, I see! For some reason I didn't spot the parent comment.