First thing to do is to read the manual (comes with the snapshot, I hope), where I tried to document it. Mark and I are writing the paper! You could try "Putting type annotations to work" by Odersky and Laufer for some useful background Simon -----Original Message----- From: Sean Seefried [mailto:seefried@itee.uq.edu.au] Sent: 14 February 2002 00:52 To: glasgow-haskell-users@haskell.org Subject: A question about GHC-5.03 One of the new features of the latest snapshot of GHC is that : "The type system now supports arbitrary rank polymorphism, given appropriate type annotations." Could you point me to some literature on this feature and how it is used? I'm familiar with rank-2 polymorphic types. I am not however familiar with what an "appropriate type annotation" is. Sean Seefried