:2:10: error: • Found hole: _ :: f a Where: ‘f’, ‘a’ are rigid type variables bound by the inferred type of it :: Functor f => f (Maybe a) at :2:1-10 • In the second argument of ‘(<$>)’, namely ‘_’ In the expression: Just <$> _ In an equation for ‘it’: it = Just <$> _ • Relevant bindings include it :: f (Maybe a) (bound at :2:1) Constraints include Functor f (from :2:1-10)