clueless

GHCi, version 6.8.2: http://www.haskell.org/ghc/  :? for helpLoading package base ... linking ... done.Prelude> import Data.Graph.Inductive.ExamplePrelude Data.Graph.Inductive.Example> star 6<interactive>:1:0:    Ambiguous type variable `gr' in the constraint:      `Data.Graph.Inductive.Graph.Graph gr'        arising from a use of `star' at <interactive>:1:0-5    Probable fix: add a type signature that fixes these type variable(s)Prelude Data.Graph.Inductive.Example> Leaving GHCi.