For those as confused as I was: "x^" is how the author renders "x̂" (or x-with-circumflex, for the font-challenged).

Something seems to be wrong with how Chrome renders this: http://imgur.com/a/z1tLz

Funny, works fine on mobile Chrome: http://imgur.com/ZZseIyB

It actually works fine for me on Chrome on Linux if I change the font to almost anything but Verdana. The mobile Chrome screenshot seems to be using Roboto, so that would explain the difference.

A bug in Verdana (as it seems to affect Firefox on Linux too)?

Is it even op to the font to decide this? It seems that there's some confusion about whether it should combine with the previous or the following character.

Combining characters are defined (in Unicode, at least) to always combine with the previous base character.

Not that it kept me awake at night, but the question did pop up in my head from time to time. It may be more a topic of cultural history than anything else, but it's nice to get close to an answer.

Ah, this makes much more sense considering the big lambda, that is just an angle, ie. a big ^, \hat, carret, whatchamacallit - not a topped over small y.

B^A counts functions from A to B. Curious if he was thinking about exponentials.