10 lines
243 B
Text
10 lines
243 B
Text
λ(nix : ../NixPrelude.dhall) →
|
|
let fold = ./fold.dhall nix
|
|
|
|
let null
|
|
: ∀(a : Type) → Optional a → Bool
|
|
= λ(a : Type) →
|
|
λ(xs : Optional a) →
|
|
fold a xs Bool (λ(_ : a) → True) False
|
|
|
|
in null
|