tcfail080.hs:27:1: error:
    • Could not deduce (Collection c0 a)
      from the context: Collection c a
        bound by the inferred type for ‘q’:
                   forall {c :: * -> *} {a}. Collection c a => a -> Bool
        at tcfail080.hs:27:1-27
      The type variable ‘c0’ is ambiguous
    • In the ambiguity check for the inferred type for ‘q’
      To defer the ambiguity check to use sites, enable AllowAmbiguousTypes
      When checking the inferred type
        q :: forall {c :: * -> *} {a}. Collection c a => a -> Bool