dhall-1.26.0: dhall-lang/tests/normalization/success/unit/OptionalBuildImplementationB.dhall
λ(T : Type) → λ(f : ∀(optional : Type) → (T → optional) → optional → optional) → f (Optional T) (λ(a : T) → Some a) (None T)
λ(T : Type) → λ(f : ∀(optional : Type) → (T → optional) → optional → optional) → f (Optional T) (λ(a : T) → Some a) (None T)