Initial commit: definition of regular expression, algebraic properties of + and ;
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name: regex
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depend: standard-library-2.2
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include: src
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{-# OPTIONS --safe --without-K #-}
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open import Data.Nat.Base hiding (_+_)
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module Regex (α : ℕ) where
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import Algebra.Definitions
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open import Algebra.Structures
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open import Data.Bool.Base
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open import Data.Fin.Base using (Fin)
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open import Data.Fin.Properties using (_≟_)
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open import Data.List.Base
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open import Data.Product.Base
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open import Data.Sum.Base
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open import Function.Base
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open import Relation.Nullary
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open import Relation.Unary
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open import Relation.Binary hiding (Decidable)
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-- Note: we do not define negation or intersections.
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-- These can be derived, but only by a double-exponential blow-up in space.
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-- So in the future we should consider adding them.
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data Regex : Set where
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-- Do not recognize any strings
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Λ : Regex
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-- Union
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_+_ : Regex → Regex → Regex
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-- Sequencing: first one, and then the other
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_⨟_ : Regex → Regex → Regex
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-- Kleene star
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_⋆ : Regex → Regex
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-- Recognize a single character
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⁅_⁆ : Fin α → Regex
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ε : Regex
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ε = Λ ⋆
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-- Do we accept the empty string?
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data A : Regex → Set where
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+ₗ : ∀ {r₁ r₂} → A r₁ → A (r₁ + r₂)
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+ᵣ : ∀ {r₁ r₂} → A r₂ → A (r₁ + r₂)
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_⨟_ : ∀ {r₁ r₂} → A r₁ → A r₂ → A (r₁ ⨟ r₂)
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star : ∀ {r} → A (r ⋆)
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-- ε accepts the empty string
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Aε : A ε
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Aε = star
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-- A is decidable!
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A? : Decidable A
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A? Λ = no λ ()
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A? (r₁ + r₂) = map′
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[ +ₗ , +ᵣ ]′
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(λ { (+ₗ Ar₁) → inj₁ Ar₁
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; (+ᵣ Ar₂) → inj₂ Ar₂
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}
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)
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(A? r₁ ⊎-dec A? r₂)
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A? (r₁ ⨟ r₂) = map′
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(uncurry _⨟_)
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(λ { (Ar₁ ⨟ Ar₂) → Ar₁ , Ar₂})
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(A? r₁ ×-dec A? r₂)
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A? (r ⋆) = yes star
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A? ⁅ x ⁆ = no λ ()
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-- Take the Brzozowski derivative of a regular expression by a
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-- character
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δ : Regex → Fin α → Regex
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δ Λ i = Λ
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δ (r₁ + r₂) i = δ r₁ i + δ r₂ i
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δ (r₁ ⨟ r₂) i = if does (A? r₁)
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then δ r₂ i + (δ r₁ i ⨟ r₂)
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else (δ r₁ i ⨟ r₂)
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δ (r ⋆) i = δ r i ⨟ (r ⋆)
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δ ⁅ x ⁆ i = if does (x ≟ i) then ε else Λ
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-- Take the Brzozowski derivative of a regular expression by a
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-- string of characters
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δ⋆ : Regex → List (Fin α) → Regex
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δ⋆ = foldl δ
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-- Whether a regular expression expresses a particular string
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Accepts : Regex → List (Fin α) → Set
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Accepts r as = A (δ⋆ r as)
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-- Accepts is decidable!
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Accepts? : ∀ r as → Dec (Accepts r as)
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Accepts? r as = A? (δ⋆ r as)
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------------------------------------------------------------------------
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-- Relations on regeces
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_⊑_ : Rel Regex _
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r₁ ⊑ r₂ = ∀ as → Accepts r₁ as → Accepts r₂ as
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_⊒_ : Rel Regex _
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r₁ ⊒ r₂ = r₂ ⊑ r₁
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_≈_ : Rel Regex _
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r₁ ≈ r₂ = (r₁ ⊑ r₂) × (r₁ ⊒ r₂)
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{-# OPTIONS --safe --without-K #-}
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open import Data.Nat.Base using (ℕ)
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module Regex.Properties (α : ℕ) where
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open import Regex α
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import Regex.Properties.Sub α as ⊑
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import Regex.Properties.Super α as ⊒
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open import Algebra.Definitions _≈_
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open import Algebra.Structures _≈_
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open import Data.Product.Base using (_,_)
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open import Relation.Binary
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------------------------------------------------------------------------
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-- General properties
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≈-refl : Reflexive _≈_
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≈-refl = ⊑.refl , ⊒.refl
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≈-sym : Symmetric _≈_
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≈-sym (p , q) = q , p
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≈-trans : Transitive _≈_
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≈-trans (p , q) (r , s) = ⊑.trans p r , ⊒.trans q s
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≈-isEquivalence : IsEquivalence _≈_
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≈-isEquivalence = record
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{ refl = ≈-refl
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; sym = ≈-sym
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; trans = ≈-trans
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}
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setoid : Setoid _ _
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setoid = record { isEquivalence = ≈-isEquivalence }
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------------------------------------------------------------------------
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-- Algebraic properties
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-- Properties of _+_
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+-cong : Congruent₂ _+_
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+-cong (x⊑y , x⊒y) (u⊑v , u⊒v) = ⊑.+-cong x⊑y u⊑v , ⊒.+-cong x⊒y u⊒v
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+-assoc : Associative _+_
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+-assoc r₁ r₂ r₃ = ⊑.+-assoc r₁ r₂ r₃ , ⊒.+-assoc r₁ r₂ r₃
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+-comm : Commutative _+_
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+-comm r₁ r₂ = ⊑.+-comm r₁ r₂ , ⊒.+-comm r₁ r₂
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+-idem : Idempotent _+_
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+-idem r = ⊑.+-idem r , ⊒.+-idem r
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+-identityˡ : LeftIdentity Λ _+_
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+-identityˡ r = ⊑.+-identityˡ r , ⊒.+-identityˡ r
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+-identityʳ : RightIdentity Λ _+_
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+-identityʳ r = ⊑.+-identityʳ r , ⊒.+-identityʳ r
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+-identity : Identity Λ _+_
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+-identity = +-identityˡ , +-identityʳ
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-- Properties of _⨟_
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⨟-cong : Congruent₂ _⨟_
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⨟-cong (x⊑y , x⊒y) (u⊑v , u⊒v) = ⊑.⨟-cong x⊑y u⊑v , ⊒.⨟-cong x⊒y u⊒v
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⨟-distribˡ-+ : _⨟_ DistributesOverˡ _+_
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⨟-distribˡ-+ r₁ r₂ r₃ = ⊑.⨟-distribˡ-+ r₁ r₂ r₃ , ⊒.⨟-distribˡ-+ r₁ r₂ r₃
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⨟-distribʳ-+ : _⨟_ DistributesOverʳ _+_
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⨟-distribʳ-+ r₁ r₂ r₃ = ⊑.⨟-distribʳ-+ r₁ r₂ r₃ , ⊒.⨟-distribʳ-+ r₁ r₂ r₃
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⨟-distrib-+ : _⨟_ DistributesOver _+_
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⨟-distrib-+ = ⨟-distribˡ-+ , ⨟-distribʳ-+
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⨟-assoc : Associative _⨟_
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⨟-assoc r₁ r₂ r₃ = ⊑.⨟-assoc r₁ r₂ r₃ , ⊒.⨟-assoc r₁ r₂ r₃
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⨟-zeroˡ : LeftZero Λ _⨟_
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⨟-zeroˡ r = ⊑.⨟-zeroˡ r , ⊒.⨟-zeroˡ r
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⨟-zeroʳ : RightZero Λ _⨟_
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⨟-zeroʳ r = ⊑.⨟-zeroʳ r , ⊒.⨟-zeroʳ r
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⨟-zero : Zero Λ _⨟_
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⨟-zero = ⨟-zeroˡ , ⨟-zeroʳ
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⨟-identityˡ : LeftIdentity ε _⨟_
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⨟-identityˡ r = ⊑.⨟-identityˡ r , ⊒.⨟-identityˡ r
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⨟-identityʳ : RightIdentity ε _⨟_
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⨟-identityʳ r = ⊑.⨟-identityʳ r , ⊒.⨟-identityʳ r
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⨟-identity : Identity ε _⨟_
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⨟-identity = ⨟-identityˡ , ⨟-identityʳ
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------------------------------------------------------------------------
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-- Algebraic structures
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+-isMagma : IsMagma _+_
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+-isMagma = record
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{ isEquivalence = ≈-isEquivalence
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; ∙-cong = +-cong
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}
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+-isSemigroup : IsSemigroup _+_
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+-isSemigroup = record
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{ isMagma = +-isMagma
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; assoc = +-assoc
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}
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+-isMonoid : IsMonoid _+_ Λ
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+-isMonoid = record
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{ isSemigroup = +-isSemigroup
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; identity = +-identity
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}
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+-isCommutativeMonoid : IsCommutativeMonoid _+_ Λ
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+-isCommutativeMonoid = record
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{ isMonoid = +-isMonoid
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; comm = +-comm
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}
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+-⨟-isSemiringWithoutAnnihilatingZero : IsSemiringWithoutAnnihilatingZero _+_ _⨟_ Λ ε
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+-⨟-isSemiringWithoutAnnihilatingZero = record
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{ +-isCommutativeMonoid = +-isCommutativeMonoid
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; *-cong = ⨟-cong
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; *-assoc = ⨟-assoc
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; *-identity = ⨟-identity
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; distrib = ⨟-distrib-+
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}
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+-⨟-isSemiring : IsSemiring _+_ _⨟_ Λ ε
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+-⨟-isSemiring = record
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{ isSemiringWithoutAnnihilatingZero = +-⨟-isSemiringWithoutAnnihilatingZero
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; zero = ⨟-zero
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}
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+-⨟-isIdempotentSemiring : IsIdempotentSemiring _+_ _⨟_ Λ ε
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+-⨟-isIdempotentSemiring = record
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{ isSemiring = +-⨟-isSemiring
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; +-idem = +-idem
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}
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{-# OPTIONS --safe --without-K #-}
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open import Data.Nat.Base using (ℕ)
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module Regex.Properties.Core (α : ℕ) where
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open import Regex α
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open import Data.List.Base using ([]; _∷_)
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open import Data.Sum.Base using (_⊎_; inj₁; inj₂)
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open import Relation.Nullary.Negation.Core using (¬_)
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-- Λ does not accept any string
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end : ∀ as → ¬ Accepts Λ as
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end [] ()
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end (a ∷ as) p = end as p
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split : ∀ {r₁ r₂} as → Accepts (r₁ + r₂) as → Accepts r₁ as ⊎ Accepts r₂ as
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split [] (+ₗ p) = inj₁ p
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split [] (+ᵣ p) = inj₂ p
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split (a ∷ as) p = split as p
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join₁ : ∀ {r₁ r₂} as → Accepts r₁ as → Accepts (r₁ + r₂) as
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join₁ [] p = +ₗ p
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join₁ (a ∷ as) p = join₁ as p
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join₂ : ∀ {r₁ r₂} as → Accepts r₂ as → Accepts (r₁ + r₂) as
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join₂ [] p = +ᵣ p
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join₂ (a ∷ as) p = join₂ as p
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{-# OPTIONS --safe --without-K #-}
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open import Data.Nat.Base using (ℕ)
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module Regex.Properties.Sub (α : ℕ) where
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open import Regex α
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open import Regex.Properties.Core α
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open import Algebra.Definitions _⊑_
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open import Data.List.Base using ([]; _∷_)
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open import Data.Sum.Base using (inj₁; inj₂)
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open import Relation.Binary.Definitions
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open import Relation.Nullary.Decidable.Core using (no; yes)
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open import Relation.Nullary.Negation.Core using (contradiction)
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------------------------------------------------------------------------
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-- General properties
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refl : Reflexive _⊑_
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refl as p = p
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trans : Transitive _⊑_
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trans x y as p = y as (x as p)
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------------------------------------------------------------------------
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-- Algebraic properties
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-- Properties of _+_
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+-cong : Congruent₂ _+_
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+-cong x⊑y u⊑v as p with split as p
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... | inj₁ p′ = join₁ as (x⊑y as p′)
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... | inj₂ p′ = join₂ as (u⊑v as p′)
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+-congˡ : LeftCongruent _+_
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+-congˡ x⊑y = +-cong refl x⊑y
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+-congʳ : RightCongruent _+_
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+-congʳ x⊑y = +-cong x⊑y refl
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+-assoc : Associative _+_
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+-assoc r₁ r₂ r₃ [] (+ₗ (+ₗ p)) = +ₗ p
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+-assoc r₁ r₂ r₃ [] (+ₗ (+ᵣ p)) = +ᵣ (+ₗ p)
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+-assoc r₁ r₂ r₃ [] (+ᵣ p) = +ᵣ (+ᵣ p)
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+-assoc r₁ r₂ r₃ (a ∷ as) p = +-assoc _ _ _ as p
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+-comm : Commutative _+_
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+-comm r₁ r₂ [] (+ₗ p) = +ᵣ p
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+-comm r₁ r₂ [] (+ᵣ p) = +ₗ p
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+-comm r₁ r₂ (a ∷ as) p = +-comm _ _ as p
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+-idem : Idempotent _+_
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+-idem r [] (+ₗ p) = p
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+-idem r [] (+ᵣ p) = p
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+-idem r (a ∷ as) p = +-idem _ as p
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+-identityˡ : LeftIdentity Λ _+_
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+-identityˡ r [] (+ᵣ p) = p
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+-identityˡ r (a ∷ as) p = +-identityˡ _ as p
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+-identityʳ : RightIdentity Λ _+_
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+-identityʳ r [] (+ₗ p) = p
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+-identityʳ r (a ∷ as) p = +-identityʳ _ as p
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-- Properties of _⨟_
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⨟-cong : Congruent₂ _⨟_
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⨟-cong x⊑y u⊑v [] (p₁ ⨟ p₂) = x⊑y [] p₁ ⨟ u⊑v [] p₂
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⨟-cong {x = x} {y = y} x⊑y u⊑v (a ∷ as) p with A? x | A? y
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... | no ¬Ax | no ¬Ay = ⨟-cong (λ as′ → x⊑y (a ∷ as′)) u⊑v as p
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... | no ¬Ax | yes Ay = join₂ as (⨟-cong (λ as′ → x⊑y (a ∷ as′)) u⊑v as p)
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... | yes Ax | no ¬Ay = contradiction (x⊑y [] Ax) ¬Ay
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... | yes Ax | yes Ay with split as p
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... | inj₁ p′ = join₁ as (u⊑v (a ∷ as) p′)
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... | inj₂ p′ = join₂ as (⨟-cong (λ as′ → x⊑y (a ∷ as′)) u⊑v as p′)
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⨟-congʳ : RightCongruent _⨟_
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⨟-congʳ x⊑y = ⨟-cong x⊑y refl
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⨟-distribˡ-+ : _⨟_ DistributesOverˡ _+_
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⨟-distribˡ-+ r₁ r₂ r₃ [] (p₁ ⨟ +ₗ p₂) = +ₗ (p₁ ⨟ p₂)
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⨟-distribˡ-+ r₁ r₂ r₃ [] (p₁ ⨟ +ᵣ p₂) = +ᵣ (p₁ ⨟ p₂)
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⨟-distribˡ-+ r₁ r₂ r₃ (a ∷ as) p with A? r₁
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... | no ¬Ar₁ = ⨟-distribˡ-+ _ _ _ as p
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... | yes Ar₁ with split as p
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... | inj₁ p′ with split as p′
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... | inj₁ p″ = join₁ as (join₁ as p″)
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... | inj₂ p″ = join₂ as (join₁ as p″)
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⨟-distribˡ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₁ | inj₂ p′ with split as (⨟-distribˡ-+ _ _ _ as p′)
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... | inj₁ p″ = join₁ as (join₂ as p″)
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... | inj₂ p″ = join₂ as (join₂ as p″)
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⨟-distribʳ-+ : _⨟_ DistributesOverʳ _+_
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⨟-distribʳ-+ r₁ r₂ r₃ [] (+ₗ p₁ ⨟ p₂) = +ₗ (p₁ ⨟ p₂)
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⨟-distribʳ-+ r₁ r₂ r₃ [] (+ᵣ p₁ ⨟ p₂) = +ᵣ (p₁ ⨟ p₂)
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⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p with A? r₂ | A? r₃
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... | no ¬Ar₂ | no ¬Ar₃ = ⨟-distribʳ-+ r₁ (δ r₂ a) (δ r₃ a) as p
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... | no ¬Ar₂ | yes Ar₃ with split as p
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... | inj₁ p′ = join₂ as (join₁ as p′)
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... | inj₂ p′ with split as (⨟-distribʳ-+ r₁ _ _ as p′)
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... | inj₁ p″ = join₁ as p″
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... | inj₂ p″ = join₂ as (join₂ as p″)
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⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₂ | no ¬Ar₃ with split as p
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... | inj₁ p′ = join₁ as (join₁ as p′)
|
||||
... | inj₂ p′ with split as (⨟-distribʳ-+ r₁ (δ r₂ a) (δ r₃ a) as p′)
|
||||
... | inj₁ p″ = join₁ as (join₂ as p″)
|
||||
... | inj₂ p″ = join₂ as p″
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₂ | yes Ar₃ with split as p
|
||||
... | inj₁ p′ = join₁ as (join₁ as p′)
|
||||
... | inj₂ p′ with split as (⨟-distribʳ-+ _ _ _ as p′)
|
||||
... | inj₁ p″ = join₁ as (join₂ as p″)
|
||||
... | inj₂ p″ = join₂ as (join₂ as p″)
|
||||
|
||||
⨟-assoc : Associative _⨟_
|
||||
⨟-assoc r₁ r₂ r₃ [] ((p₁ ⨟ p₂) ⨟ p₃) = p₁ ⨟ (p₂ ⨟ p₃)
|
||||
⨟-assoc r₁ r₂ r₃ (a ∷ as) p with A? r₁
|
||||
... | no ¬Ar₁ = ⨟-assoc (δ r₁ a) r₂ r₃ as p
|
||||
... | yes Ar₁ with A? r₂
|
||||
... | no ¬Ar₂ with split as (⨟-distribʳ-+ _ _ _ as p)
|
||||
... | inj₁ p′ = join₁ as p′
|
||||
... | inj₂ p′ = join₂ as (⨟-assoc _ _ _ as p′)
|
||||
⨟-assoc r₁ r₂ r₃ (a ∷ as) p | yes Ar₁ | yes Ar₂ with split as p
|
||||
... | inj₁ p′ = join₁ as (join₁ as p′)
|
||||
... | inj₂ p′ with split as (⨟-distribʳ-+ _ _ _ as p′)
|
||||
... | inj₁ p″ = join₁ as (join₂ as p″)
|
||||
... | inj₂ p″ = join₂ as (⨟-assoc _ _ _ as p″)
|
||||
|
||||
⨟-zeroˡ : LeftZero Λ _⨟_
|
||||
⨟-zeroˡ r [] (() ⨟ _)
|
||||
⨟-zeroˡ r (a ∷ as) p = ⨟-zeroˡ r as p
|
||||
|
||||
⨟-zeroʳ : RightZero Λ _⨟_
|
||||
⨟-zeroʳ r [] (p₁ ⨟ p₂) = p₂
|
||||
⨟-zeroʳ r (a ∷ as) p with A? r
|
||||
... | no ¬Ar = ⨟-zeroʳ _ as p
|
||||
... | yes Ar with split as p
|
||||
... | inj₁ p′ = p′
|
||||
... | inj₂ p′ = ⨟-zeroʳ _ as p′
|
||||
|
||||
⨟-identityˡ : LeftIdentity ε _⨟_
|
||||
⨟-identityˡ r [] (star ⨟ p) = p
|
||||
⨟-identityˡ r (a ∷ as) p with split as p
|
||||
... | inj₁ p′ = p′
|
||||
... | inj₂ p′ = contradiction (⨟-zeroˡ _ as (⨟-assoc _ _ _ as p′)) (end as)
|
||||
|
||||
⨟-identityʳ : RightIdentity ε _⨟_
|
||||
⨟-identityʳ r [] (p ⨟ star) = p
|
||||
⨟-identityʳ r (a ∷ as) p with A? r
|
||||
... | no ¬Ar = ⨟-identityʳ _ as p
|
||||
... | yes Ar with split as p
|
||||
... | inj₁ p′ = contradiction (⨟-zeroˡ _ as p′) (end as)
|
||||
... | inj₂ p′ = ⨟-identityʳ _ as p′
|
||||
|
|
@ -0,0 +1,133 @@
|
|||
{-# OPTIONS --safe --without-K #-}
|
||||
|
||||
open import Data.Nat.Base using (ℕ)
|
||||
|
||||
module Regex.Properties.Super (α : ℕ) where
|
||||
|
||||
open import Regex α
|
||||
open import Regex.Properties.Core α
|
||||
|
||||
open import Algebra.Definitions _⊒_
|
||||
open import Data.List.Base using ([]; _∷_)
|
||||
open import Data.Sum.Base using (inj₁; inj₂)
|
||||
open import Relation.Binary.Definitions
|
||||
open import Relation.Nullary.Decidable.Core using (no; yes)
|
||||
open import Relation.Nullary.Negation.Core using (contradiction)
|
||||
|
||||
------------------------------------------------------------------------
|
||||
-- General properties
|
||||
|
||||
refl : Reflexive _⊒_
|
||||
refl as p = p
|
||||
|
||||
trans : Transitive _⊒_
|
||||
trans x y as p = x as (y as p)
|
||||
|
||||
------------------------------------------------------------------------
|
||||
-- Algebraic properties
|
||||
|
||||
+-cong : Congruent₂ _+_
|
||||
+-cong x⊒y u⊒v as p with split as p
|
||||
... | inj₁ p′ = join₁ as (x⊒y as p′)
|
||||
... | inj₂ p′ = join₂ as (u⊒v as p′)
|
||||
|
||||
+-assoc : Associative _+_
|
||||
+-assoc r₁ r₂ r₃ [] (+ₗ p) = +ₗ (+ₗ p)
|
||||
+-assoc r₁ r₂ r₃ [] (+ᵣ (+ₗ p)) = +ₗ (+ᵣ p)
|
||||
+-assoc r₁ r₂ r₃ [] (+ᵣ (+ᵣ p)) = +ᵣ p
|
||||
+-assoc r₁ r₂ r₃ (a ∷ as) p = +-assoc _ _ _ as p
|
||||
|
||||
+-comm : Commutative _+_
|
||||
+-comm r₁ r₂ [] (+ₗ p) = +ᵣ p
|
||||
+-comm r₁ r₂ [] (+ᵣ p) = +ₗ p
|
||||
+-comm r₁ r₂ (a ∷ as) p = +-comm _ _ as p
|
||||
|
||||
+-idem : Idempotent _+_
|
||||
+-idem r [] p = +ₗ p -- annoyingly not unique
|
||||
+-idem r (a ∷ as) p = +-idem _ as p
|
||||
|
||||
+-identityˡ : LeftIdentity Λ _+_
|
||||
+-identityˡ r [] p = +ᵣ p
|
||||
+-identityˡ r (a ∷ as) p = +-identityˡ _ as p
|
||||
|
||||
+-identityʳ : RightIdentity Λ _+_
|
||||
+-identityʳ r [] p = +ₗ p
|
||||
+-identityʳ r (a ∷ as) p = +-identityʳ _ as p
|
||||
|
||||
⨟-cong : Congruent₂ _⨟_
|
||||
⨟-cong x⊒y u⊒v [] (p₁ ⨟ p₂) = x⊒y [] p₁ ⨟ u⊒v [] p₂
|
||||
⨟-cong {x = x} {y = y} x⊒y u⊒v (a ∷ as) p with A? x | A? y
|
||||
... | no ¬Ax | no ¬Ay = ⨟-cong (λ as′ → x⊒y (a ∷ as′)) u⊒v as p
|
||||
... | no ¬Ax | yes Ay = contradiction (x⊒y [] Ay) ¬Ax
|
||||
... | yes Ax | no ¬Ay = join₂ as (⨟-cong (λ as′ → x⊒y (a ∷ as′)) u⊒v as p)
|
||||
... | yes Ax | yes Ay with split as p
|
||||
... | inj₁ p′ = join₁ as (u⊒v (a ∷ as) p′)
|
||||
... | inj₂ p′ = join₂ as (⨟-cong (λ as′ → x⊒y (a ∷ as′)) u⊒v as p′)
|
||||
|
||||
⨟-distribˡ-+ : _⨟_ DistributesOverˡ _+_
|
||||
⨟-distribˡ-+ r₁ r₂ r₃ [] (+ₗ (p₁ ⨟ p₂)) = p₁ ⨟ +ₗ p₂
|
||||
⨟-distribˡ-+ r₁ r₂ r₃ [] (+ᵣ (p₁ ⨟ p₂)) = p₁ ⨟ +ᵣ p₂
|
||||
⨟-distribˡ-+ r₁ r₂ r₃ (a ∷ as) p with A? r₁
|
||||
... | no ¬Ar₁ with split as p
|
||||
... | inj₁ p′ = ⨟-distribˡ-+ _ _ _ as (join₁ as p′)
|
||||
... | inj₂ p′ = ⨟-distribˡ-+ _ _ _ as (join₂ as p′)
|
||||
⨟-distribˡ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₁ with split as p
|
||||
... | inj₁ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as (join₁ as p″)
|
||||
... | inj₂ p″ = join₂ as (⨟-distribˡ-+ _ _ _ as (join₁ as p″))
|
||||
⨟-distribˡ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₁ | inj₂ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as (join₂ as p″)
|
||||
... | inj₂ p″ = join₂ as (⨟-distribˡ-+ _ _ _ as (join₂ as p″))
|
||||
|
||||
⨟-distribʳ-+ : _⨟_ DistributesOverʳ _+_
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ [] (+ₗ (p₁ ⨟ p₂)) = +ₗ p₁ ⨟ p₂
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ [] (+ᵣ (p₁ ⨟ p₂)) = +ᵣ p₁ ⨟ p₂
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p with A? r₂ | A? r₃
|
||||
... | no ¬Ar₂ | no ¬Ar₃ = ⨟-distribʳ-+ _ _ _ as p
|
||||
... | no ¬Ar₂ | yes Ar₃ with split as p
|
||||
... | inj₁ p′ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₁ as p′))
|
||||
... | inj₂ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as p″
|
||||
... | inj₂ p″ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₂ as p″))
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₂ | no ¬Ar₃ with split as p
|
||||
... | inj₂ p′ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₂ as p′))
|
||||
... | inj₁ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as p″
|
||||
... | inj₂ p″ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₁ as p″))
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₂ | yes Ar₃ with split as p
|
||||
... | inj₁ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as p″
|
||||
... | inj₂ p″ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₁ as p″))
|
||||
⨟-distribʳ-+ r₁ r₂ r₃ (a ∷ as) p | yes Ar₂ | yes Ar₃ | inj₂ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as p″
|
||||
... | inj₂ p″ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₂ as p″))
|
||||
|
||||
⨟-assoc : Associative _⨟_
|
||||
⨟-assoc r₁ r₂ r₃ [] (p₁ ⨟ (p₂ ⨟ p₃)) = (p₁ ⨟ p₂) ⨟ p₃
|
||||
⨟-assoc r₁ r₂ r₃ (a ∷ as) p with A? r₁ | A? r₂
|
||||
... | no ¬Ar₁ | no ¬Ar₂ = ⨟-assoc _ _ _ as p
|
||||
... | no ¬Ar₁ | yes Ar₂ = ⨟-assoc _ _ _ as p
|
||||
... | yes Ar₁ | no ¬Ar₂ with split as p
|
||||
... | inj₁ p′ = ⨟-distribʳ-+ _ _ _ as (join₁ as p′)
|
||||
... | inj₂ p′ = ⨟-distribʳ-+ _ _ _ as (join₂ as (⨟-assoc _ _ _ as p′))
|
||||
⨟-assoc r₁ r₂ r₃ (a ∷ as) p | yes Ar₁ | yes Ar₂ with split as p
|
||||
... | inj₂ p′ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₂ as (⨟-assoc _ _ _ as p′)))
|
||||
... | inj₁ p′ with split as p′
|
||||
... | inj₁ p″ = join₁ as p″
|
||||
... | inj₂ p″ = join₂ as (⨟-distribʳ-+ _ _ _ as (join₁ as p″))
|
||||
|
||||
⨟-zeroˡ : LeftZero Λ _⨟_
|
||||
⨟-zeroˡ r as p = contradiction p (end as)
|
||||
|
||||
⨟-zeroʳ : RightZero Λ _⨟_
|
||||
⨟-zeroʳ r as p = contradiction p (end as)
|
||||
|
||||
⨟-identityˡ : LeftIdentity ε _⨟_
|
||||
⨟-identityˡ r [] p = star ⨟ p
|
||||
⨟-identityˡ r (a ∷ as) p = join₁ as p
|
||||
|
||||
⨟-identityʳ : RightIdentity ε _⨟_
|
||||
⨟-identityʳ r [] p = p ⨟ star
|
||||
⨟-identityʳ r (a ∷ as) p with A? r
|
||||
... | no ¬Ar = ⨟-identityʳ _ as p
|
||||
... | yes Ar = join₂ as (⨟-identityʳ _ as p)
|
||||
Loading…
Reference in New Issue