[Haskell] Crazy class stuff

I tried this: class MonadTrans' i o where lift' :: i a -> o a instance (MonadTrans t, Monad m) => MonadTrans' m (t m) where lift' = lift instance (MonadTrans' a b, MonadTrans' b c) => MonadTrans' a c where lift' = lift' . lift' And it doesn't work. I know what I want it to do, how do I express it right? -- Taral <taralx@gmail.com> "You can't prove anything." -- Gödel's Incompetence Theorem