{-# OPTIONS --without-K #-} module Iff where open import lib.Base public open import lib.types.Sigma public {- Standard notation: if and only if. -} _⇔_ : ∀ {j₁ j₂} → Set j₁ → Set j₂ → Set (lmax j₁ j₂) A ⇔ B = (A → B) × (B → A)