module Bijection where open import Equality open import Function open import Level record isBij {ℓ ℓ' : Level} {A : Set ℓ} {B : Set ℓ'} (f : A → B) : ------------ Set (ℓ ⊔ ℓ') where infix 8 _⁻¹ field _⁻¹ : B → A bijl : _⁻¹ ∘ f ≡ id bijr : f ∘ _⁻¹ ≡ id open isBij{{...}} public