468060 (122) [Avatar] Offline
"Returns function 1, a selection....Returns function2, the selection.enter() function."

Functions can return other functions. However, these ones (1 and 3, p.30) don't: they return objects.
elijah.meeks (127) [Avatar] Offline
You're absolutely right, that's a sloppy way to express it. In my defense, I wrote this back when I was young and foolish.