[Haskell-cafe] RoseTree + Data.Typeable.Zipper

Hi list! Could you please give me a quick example of navigating throw Data.Typeable.Zipper built on top of a Rose Tree? eg. (See ??? in the last line - is my question) {-#LANGUAGE TemplateHaskell, DeriveDataTypeable, TypeOperators #-} import Data.Typeable.Zipper data Tree k a = Tree { _rules :: [(k,Tree k a)] } deriving(Show, Typeable) $(mkLabelsNoTypes [''Tree]) atree = Tree [(1, Tree []), (2, Tree []), (3, Tree [(11, Tree [])])] moveToLeftmostChild :: (Typeable k, Typeable a) => Zipper1 (Tree k a) -> Zipper1 (Tree k a) moveToLeftmostChild z = moveTo ??? z Thanks, Sergey