module Algebra.Morphism where
open import Relation.Binary
open import Algebra
open import Algebra.FunctionProperties
import Algebra.Properties.Group as GroupP
open import Function
open import Level
import Relation.Binary.EqReasoning as EqR
module Definitions {f t ℓ}
(From : Set f) (To : Set t) (_≈_ : Rel To ℓ) where
Morphism : Set _
Morphism = From → To
Homomorphic₀ : Morphism → From → To → Set _
Homomorphic₀ ⟦_⟧ ∙ ∘ = ⟦ ∙ ⟧ ≈ ∘
Homomorphic₁ : Morphism → Fun₁ From → Op₁ To → Set _
Homomorphic₁ ⟦_⟧ ∙_ ∘_ = ∀ x → ⟦ ∙ x ⟧ ≈ (∘ ⟦ x ⟧)
Homomorphic₂ : Morphism → Fun₂ From → Op₂ To → Set _
Homomorphic₂ ⟦_⟧ _∙_ _∘_ =
∀ x y → ⟦ x ∙ y ⟧ ≈ (⟦ x ⟧ ∘ ⟦ y ⟧)
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : Semigroup c₁ ℓ₁)
(To : Semigroup c₂ ℓ₂) where
private
module F = Semigroup From
module T = Semigroup To
open Definitions F.Carrier T.Carrier T._≈_
record IsSemigroupMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
⟦⟧-cong : ⟦_⟧ Preserves F._≈_ ⟶ T._≈_
∙-homo : Homomorphic₂ ⟦_⟧ F._∙_ T._∙_
syntax IsSemigroupMorphism From To F = F Is From -Semigroup⟶ To
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : Monoid c₁ ℓ₁)
(To : Monoid c₂ ℓ₂) where
private
module F = Monoid From
module T = Monoid To
open Definitions F.Carrier T.Carrier T._≈_
record IsMonoidMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
sm-homo : IsSemigroupMorphism F.semigroup T.semigroup ⟦_⟧
ε-homo : Homomorphic₀ ⟦_⟧ F.ε T.ε
open IsSemigroupMorphism sm-homo public
syntax IsMonoidMorphism From To F = F Is From -Monoid⟶ To
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : CommutativeMonoid c₁ ℓ₁)
(To : CommutativeMonoid c₂ ℓ₂) where
private
module F = CommutativeMonoid From
module T = CommutativeMonoid To
open Definitions F.Carrier T.Carrier T._≈_
record IsCommutativeMonoidMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
mn-homo : IsMonoidMorphism F.monoid T.monoid ⟦_⟧
open IsMonoidMorphism mn-homo public
syntax IsCommutativeMonoidMorphism From To F = F Is From -CommutativeMonoid⟶ To
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : IdempotentCommutativeMonoid c₁ ℓ₁)
(To : IdempotentCommutativeMonoid c₂ ℓ₂) where
private
module F = IdempotentCommutativeMonoid From
module T = IdempotentCommutativeMonoid To
open Definitions F.Carrier T.Carrier T._≈_
record IsIdempotentCommutativeMonoidMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
mn-homo : IsMonoidMorphism F.monoid T.monoid ⟦_⟧
open IsMonoidMorphism mn-homo public
isCommutativeMonoidMorphism :
IsCommutativeMonoidMorphism F.commutativeMonoid T.commutativeMonoid ⟦_⟧
isCommutativeMonoidMorphism = record { mn-homo = mn-homo }
syntax IsIdempotentCommutativeMonoidMorphism From To F = F Is From -IdempotentCommutativeMonoid⟶ To
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : Group c₁ ℓ₁)
(To : Group c₂ ℓ₂) where
private
module F = Group From
module T = Group To
open Definitions F.Carrier T.Carrier T._≈_
record IsGroupMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
mn-homo : IsMonoidMorphism F.monoid T.monoid ⟦_⟧
open IsMonoidMorphism mn-homo public
⁻¹-homo : Homomorphic₁ ⟦_⟧ F._⁻¹ T._⁻¹
⁻¹-homo x = let open EqR T.setoid in T.uniqueˡ-⁻¹ ⟦ x F.⁻¹ ⟧ ⟦ x ⟧ $ begin
⟦ x F.⁻¹ ⟧ T.∙ ⟦ x ⟧ ≈⟨ T.sym (∙-homo (x F.⁻¹) x) ⟩
⟦ x F.⁻¹ F.∙ x ⟧ ≈⟨ ⟦⟧-cong (F.inverseˡ x) ⟩
⟦ F.ε ⟧ ≈⟨ ε-homo ⟩
T.ε ∎
syntax IsGroupMorphism From To F = F Is From -Group⟶ To
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : AbelianGroup c₁ ℓ₁)
(To : AbelianGroup c₂ ℓ₂) where
private
module F = AbelianGroup From
module T = AbelianGroup To
open Definitions F.Carrier T.Carrier T._≈_
record IsAbelianGroupMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
gp-homo : IsGroupMorphism F.group T.group ⟦_⟧
open IsGroupMorphism gp-homo public
syntax IsAbelianGroupMorphism From To F = F Is From -AbelianGroup⟶ To
module _ {c₁ ℓ₁ c₂ ℓ₂}
(From : Ring c₁ ℓ₁)
(To : Ring c₂ ℓ₂) where
private
module F = Ring From
module T = Ring To
open Definitions F.Carrier T.Carrier T._≈_
record IsRingMorphism (⟦_⟧ : Morphism) :
Set (c₁ ⊔ ℓ₁ ⊔ c₂ ⊔ ℓ₂) where
field
+-abgp-homo : ⟦_⟧ Is F.+-abelianGroup -AbelianGroup⟶ T.+-abelianGroup
*-mn-homo : ⟦_⟧ Is F.*-monoid -Monoid⟶ T.*-monoid
syntax IsRingMorphism From To F = F Is From -Ring⟶ To