------------------------------------------------------------------------ -- The Agda standard library -- -- Non-dependent product combinators for propositional equality -- preserving functions ------------------------------------------------------------------------ {-# OPTIONS --cubical-compatible --safe #-} module Data.Product.Function.NonDependent.Propositional where open import Data.Product.Base using (_×_; map) open import Data.Product.Function.NonDependent.Setoid open import Data.Product.Relation.Binary.Pointwise.NonDependent open import Function open import Function.Properties.Inverse as Inv open import Function.Related.Propositional open import Function.Construct.Composition as Compose open import Level using (Level; _⊔_) open import Relation.Binary hiding (_⇔_) open import Relation.Binary.PropositionalEquality using (setoid) private variable a b c d : Level A B C D : Set a ------------------------------------------------------------------------ -- Helper lemma private liftViaInverse : {R : ∀ {a b ℓ₁ ℓ₂} → REL (Setoid a ℓ₁) (Setoid b ℓ₂) (a ⊔ b ⊔ ℓ₁ ⊔ ℓ₂)} → (∀ {a b c ℓ₁ ℓ₂ ℓ₃} {S : Setoid a ℓ₁} {T : Setoid b ℓ₂} {U : Setoid c ℓ₃} → R S T → R T U → R S U) → (∀ {a b ℓ₁ ℓ₂} {S : Setoid a ℓ₁} {T : Setoid b ℓ₂} → Inverse S T → R S T) → (R (setoid A) (setoid C) → R (setoid B) (setoid D) → R (setoid A ×ₛ setoid B) (setoid C ×ₛ setoid D)) → R (setoid A) (setoid C) → R (setoid B) (setoid D) → R (setoid (A × B)) (setoid (C × D)) liftViaInverse trans inv⇒R lift RAC RBD = Inv.transportVia trans inv⇒R (Inv.sym Pointwise-≡↔≡) (lift RAC RBD) Pointwise-≡↔≡ ------------------------------------------------------------------------ -- Combinators for various function types infixr 2 _×-⇔_ _×-↣_ _×-↠_ _×-⤖_ _×-↩_ _×-↪_ _×-↔_ _×-⟶_ : A ⟶ B → C ⟶ D → (A × C) ⟶ (B × D) _×-⟶_ = liftViaInverse Compose.function Inv.toFunction _×-function_ _×-⇔_ : A ⇔ B → C ⇔ D → (A × C) ⇔ (B × D) _×-⇔_ = liftViaInverse Compose.equivalence Inverse⇒Equivalence _×-equivalence_ _×-↣_ : A ↣ B → C ↣ D → (A × C) ↣ (B × D) _×-↣_ = liftViaInverse Compose.injection Inverse⇒Injection _×-injection_ _×-↠_ : A ↠ B → C ↠ D → (A × C) ↠ (B × D) _×-↠_ = liftViaInverse Compose.surjection Inverse⇒Surjection _×-surjection_ _×-⤖_ : A ⤖ B → C ⤖ D → (A × C) ⤖ (B × D) _×-⤖_ = liftViaInverse Compose.bijection Inverse⇒Bijection _×-bijection_ _×-↩_ : A ↩ B → C ↩ D → (A × C) ↩ (B × D) _×-↩_ = liftViaInverse Compose.leftInverse Inverse.leftInverse _×-leftInverse_ _×-↪_ : A ↪ B → C ↪ D → (A × C) ↪ (B × D) _×-↪_ = liftViaInverse Compose.rightInverse Inverse.rightInverse _×-rightInverse_ _×-↔_ : A ↔ B → C ↔ D → (A × C) ↔ (B × D) _×-↔_ = liftViaInverse Compose.inverse id _×-inverse_ infixr 2 _×-cong_ _×-cong_ : ∀ {k} → A ∼[ k ] B → C ∼[ k ] D → (A × C) ∼[ k ] (B × D) _×-cong_ {k = implication} = _×-⟶_ _×-cong_ {k = reverseImplication} = _×-⟶_ _×-cong_ {k = equivalence} = _×-⇔_ _×-cong_ {k = injection} = _×-↣_ _×-cong_ {k = reverseInjection} = _×-↣_ _×-cong_ {k = leftInverse} = _×-↪_ _×-cong_ {k = surjection} = _×-↠_ _×-cong_ {k = bijection} = _×-↔_