{- Empty type and negation in the ambient type theory. -} module basic.empty where open import basic.prelude private variable ℓ : Level --↓ Empty type. data 𝟘 : Type where --↓ Elimination from the empty type. 𝟘-elim : {A : 𝟘 → Type ℓ} → (v : 𝟘) → A v 𝟘-elim () --↓ Non-dependent elimination from the empty type. 𝟘-rec : {A : Type ℓ} → 𝟘 → A 𝟘-rec () --↓ Negation of a type. ¬_ : Type ℓ → Type ℓ ¬ A = A → 𝟘