They always go for the mathematical way of explaining stuff (this is not a compliment). Programmer English please, not Alien Math. (And that's me saying as someone who likes Alien math in general. But I just don't see the point in using it when programming).
Ok cool, your programming language now has two worlds, the functional world and the imperative world and they have two different syntaxes and you have to pass your world as an extra parameter and etc etc
And I personally find the syntactic sugar built on top of it confuses more than helps (ok, some of it is just Haskell being Haskell, but it confuses)