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-rw-r--r--Functor/Instance/Multiset.agda60
1 files changed, 36 insertions, 24 deletions
diff --git a/Functor/Instance/Multiset.agda b/Functor/Instance/Multiset.agda
index 0adb1df..b961c7b 100644
--- a/Functor/Instance/Multiset.agda
+++ b/Functor/Instance/Multiset.agda
@@ -4,18 +4,20 @@ open import Level using (Level; _⊔_)
module Functor.Instance.Multiset {c ℓ : Level} where
-import Data.List as List
+import Data.Opaque.List as L
import Data.List.Properties as ListProps
import Data.List.Relation.Binary.Pointwise as PW
-open import Data.List.Relation.Binary.Permutation.Setoid using (↭-setoid; ↭-reflexive-≋)
-open import Data.List.Relation.Binary.Permutation.Setoid.Properties using (map⁺)
-
open import Categories.Category.Instance.Setoids using (Setoids)
open import Categories.Functor using (Functor)
-open import Data.Setoid using (∣_∣)
+open import Data.List.Relation.Binary.Permutation.Setoid using (↭-setoid; ↭-reflexive-≋)
+open import Data.List.Relation.Binary.Permutation.Setoid.Properties using (map⁺)
+open import Data.Opaque.Multiset using (Multisetₛ; mapₛ)
+open import Data.Setoid using (∣_∣; _⇒ₛ_)
open import Function.Base using (_∘_; id)
open import Function.Bundles using (Func; _⟶ₛ_; _⟨$⟩_)
+open import Function.Construct.Identity using () renaming (function to Id)
+open import Function.Construct.Setoid using (_∙_)
open import Relation.Binary using (Setoid)
open Functor
@@ -29,32 +31,42 @@ private
-- the Multiset functor takes a carrier A to lists of A
-- and the equivalence on A to permutation equivalence on lists of A
-Multisetₛ : Setoid c ℓ → Setoid c (c ⊔ ℓ)
-Multisetₛ x = ↭-setoid x
-
-- Multiset on morphisms applies the same function to every element of a multiset
-mapₛ : A ⟶ₛ B → Multisetₛ A ⟶ₛ Multisetₛ B
-mapₛ f .to = List.map (to f)
-mapₛ {A} {B} f .cong = map⁺ A B (cong f)
+opaque
+ unfolding mapₛ
+
+ map-id
+ : (xs : ∣ Multisetₛ A ∣)
+ → (open Setoid (Multisetₛ A))
+ → mapₛ (Id A) ⟨$⟩ xs ≈ xs
+ map-id {A} = reflexive (Multisetₛ A) ∘ ListProps.map-id
+
+opaque
+ unfolding mapₛ
-map-id
- : (xs : ∣ Multisetₛ A ∣)
- → (open Setoid (Multisetₛ A))
- → List.map id xs ≈ xs
-map-id {A} = reflexive (Multisetₛ A) ∘ ListProps.map-id
+ Multiset-homo
+ : (f : A ⟶ₛ B)
+ (g : B ⟶ₛ C)
+ → (xs : ∣ Multisetₛ A ∣)
+ → (open Setoid (Multisetₛ C))
+ → mapₛ (g ∙ f) ⟨$⟩ xs ≈ mapₛ g ⟨$⟩ (mapₛ f ⟨$⟩ xs)
+ Multiset-homo {C = C} f g = reflexive (Multisetₛ C) ∘ ListProps.map-∘
-Multiset-homo
- : (f : A ⟶ₛ B)
- (g : B ⟶ₛ C)
- → (xs : ∣ Multisetₛ A ∣)
- → (open Setoid (Multisetₛ C))
- → List.map (to g ∘ to f) xs ≈ List.map (to g) (List.map (to f) xs)
-Multiset-homo {C = C} f g = reflexive (Multisetₛ C) ∘ ListProps.map-∘
+opaque
+ unfolding mapₛ
+
+ Multiset-resp-≈
+ : (f g : A ⟶ₛ B)
+ → (let open Setoid (A ⇒ₛ B) in f ≈ g)
+ → (let open Setoid (Multisetₛ A ⇒ₛ Multisetₛ B) in mapₛ f ≈ mapₛ g)
+ Multiset-resp-≈ {A} {B} f g f≈g = ↭-reflexive-≋ B (PW.map⁺ (to f) (to g) (PW.refl f≈g))
Multiset : Functor (Setoids c ℓ) (Setoids c (c ⊔ ℓ))
Multiset .F₀ = Multisetₛ
Multiset .F₁ = mapₛ
Multiset .identity {A} {xs} = map-id {A} xs
Multiset .homomorphism {f = f} {g} {xs} = Multiset-homo f g xs
-Multiset .F-resp-≈ {A} {B} {f} {g} f≈g = ↭-reflexive-≋ B (PW.map⁺ (to f) (to g) (PW.refl f≈g))
+Multiset .F-resp-≈ {A} {B} {f} {g} f≈g = Multiset-resp-≈ f g f≈g
+
+module Multiset = Functor Multiset