splitAt :: Index -> Sequence a -> (Sequence a, Sequence a)
splitAt i (Sequence x) = (Sequence a, Sequence b)
  where
    (a, b) = FT.split (Size i <) x
splitAt :: Index -> Sequence a -> (Sequence a, Sequence a)
splitAt i (Sequence x) = (Sequence a, Sequence b)
  where
    (a, b) = FT.split (Size i <) x
splitAt i (Sequence x) = (Sequence a, Sequence b)
  where
    (a, b) = FT.split (Size i <) x