In Haskell it's generally considered bad form to omit type annotations for your top-level functions. There is even a compiler warning for this sort of thing. Thankfully, the Haskell plugins for good editors (vim or emacs) provide hotkeys to automatically insert an inferred type annotation for a function you specify.

Yeah this mysterious "typed haskell" thing seems to imply that the other version doesn't have types, while of course they are inferred.