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

> %name Vect xs, ys, zs

> append : Vect n a -> Vect m a -> Vect (n + m) a
> append {n} xs ys = ?foo

> vadd : Num a => Vect n a -> Vect n a -> Vect n a
> vadd [] ys = ?bar
> vadd (x :: xs) ys = ?baz

> suc : (x : Nat) -> (y : Nat) -> x = y -> S x = S y
> suc x y prf = ?quux

> suc' : x = y -> S x = S y
> suc' {x} {y} prf = ?quuz