λ(nix : ../NixPrelude.dhall) →
  let NonEmpty = ./Type.dhall

  let Optional/default = ../Optional/default.dhall nix

  let last
      : ∀(a : Type) → NonEmpty a → a
      = λ(a : Type) →
        λ(xs : NonEmpty a) →
          Optional/default a xs.head (List/last a xs.tail)

  in  last