Hello Haskell gurus,<br><br>I am trying to understand "kind" <br><br>Prelude> :k Maybe<br>Maybe :: * -> *<br>Prelude> :k (->)<br>(->) :: ?? -> ? -> *<br><br clear="all">What are the question marks? Why are they different from *? How is this related to rank-2 polymorphism?<br>
<br>Thanks in advance,<br><br>Regards,<br>Amitava Shee<br><br>