> data Vect : Nat -> Type -> Type where
>      Nil : Vect Z a
>      (::) : a -> Vect k a -> Vect (S k) a

> %name Vect xs, ys, zs

> transposeHelper : Vect m a -> (1 xs_trans : Vect m (Vect k a)) -> Vect m (Vect (S k) a)
