agda-spa/Lattice.agda
Danila Fedorin 971d75bb2b Parameterize by equivalence type
Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>
2023-07-15 14:40:11 -07:00

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module Lattice where
import Data.Nat.Properties as NatProps
open import Relation.Binary.PropositionalEquality as Eq using (_≡_; sym)
open import Relation.Binary.Definitions
open import Data.Nat as Nat using (; _≤_)
open import Data.Product using (_×_; _,_)
open import Data.Sum using (_⊎_; inj₁; inj₂)
open import Agda.Primitive using (lsuc; Level)
open import NatMap using (NatMap)
record IsSemilattice {a} (A : Set a)
(_≈_ : A A Set a)
(_⊔_ : A A A) : Set a where
field
⊔-assoc : (x y z : A) ((x y) z) (x (y z))
⊔-comm : (x y : A) (x y) (y x)
⊔-idemp : (x : A) (x x) x
record IsLattice {a} (A : Set a)
(_≈_ : A A Set a)
(_⊔_ : A A A)
(_⊓_ : A A A) : Set a where
field
joinSemilattice : IsSemilattice A _≈_ _⊔_
meetSemilattice : IsSemilattice A _≈_ _⊓_
absorb-⊔-⊓ : (x y : A) (x (x y)) x
absorb-⊓-⊔ : (x y : A) (x (x y)) x
open IsSemilattice joinSemilattice public
open IsSemilattice meetSemilattice public renaming
( ⊔-assoc to ⊓-assoc
; ⊔-comm to ⊓-comm
; ⊔-idemp to ⊓-idemp
)
record Semilattice {a} (A : Set a) : Set (lsuc a) where
field
_≈_ : A A Set a
_⊔_ : A A A
isSemilattice : IsSemilattice A _≈_ _⊔_
open IsSemilattice isSemilattice public
record Lattice {a} (A : Set a) : Set (lsuc a) where
field
_≈_ : A A Set a
_⊔_ : A A A
_⊓_ : A A A
isLattice : IsLattice A _≈_ _⊔_ _⊓_
open IsLattice isLattice public
module IsSemilatticeInstances where
module ForNat where
open Nat
open NatProps
open Eq
NatIsMaxSemilattice : IsSemilattice _≡_ _⊔_
NatIsMaxSemilattice = record
{ ⊔-assoc = ⊔-assoc
; ⊔-comm = ⊔-comm
; ⊔-idemp = ⊔-idem
}
NatIsMinSemilattice : IsSemilattice _≡_ _⊓_
NatIsMinSemilattice = record
{ ⊔-assoc = ⊓-assoc
; ⊔-comm = ⊓-comm
; ⊔-idemp = ⊓-idem
}
module ForProd {a} {A B : Set a}
(_≈₁_ : A A Set a) (_≈₂_ : B B Set a)
(_⊔₁_ : A A A) (_⊔₂_ : B B B)
(sA : IsSemilattice A _≈₁_ _⊔₁_) (sB : IsSemilattice B _≈₂_ _⊔₂_) where
open Eq
open Data.Product
private
infix 4 _≈_
infixl 20 _⊔_
_≈_ : A × B A × B Set a
(a₁ , b₁) (a₂ , b₂) = (a₁ ≈₁ a₂) × (b₁ ≈₂ b₂)
_⊔_ : A × B A × B A × B
(a₁ , b₁) (a₂ , b₂) = (a₁ ⊔₁ a₂ , b₁ ⊔₂ b₂)
⊔-assoc : (p₁ p₂ p₃ : A × B) (p₁ p₂) p₃ p₁ (p₂ p₃)
⊔-assoc (a₁ , b₁) (a₂ , b₂) (a₃ , b₃) =
( IsSemilattice.⊔-assoc sA a₁ a₂ a₃
, IsSemilattice.⊔-assoc sB b₁ b₂ b₃
)
⊔-comm : (p₁ p₂ : A × B) p₁ p₂ p₂ p₁
⊔-comm (a₁ , b₁) (a₂ , b₂) =
( IsSemilattice.⊔-comm sA a₁ a₂
, IsSemilattice.⊔-comm sB b₁ b₂
)
⊔-idemp : (p : A × B) p p p
⊔-idemp (a , b) =
( IsSemilattice.⊔-idemp sA a
, IsSemilattice.⊔-idemp sB b
)
ProdIsSemilattice : IsSemilattice (A × B) _≈_ _⊔_
ProdIsSemilattice = record
{ ⊔-assoc = ⊔-assoc
; ⊔-comm = ⊔-comm
; ⊔-idemp = ⊔-idemp
}
module IsLatticeInstances where
module ForNat where
open Nat
open NatProps
open Eq
open IsSemilatticeInstances.ForNat
open Data.Product
private
max-bound₁ : {x y z : } x y z x z
max-bound₁ {x} {y} {z} x⊔y≡z
rewrite sym x⊔y≡z
rewrite ⊔-comm x y = m≤n⇒m≤o⊔n y (≤-refl)
min-bound₁ : {x y z : } x y z z x
min-bound₁ {x} {y} {z} x⊓y≡z
rewrite sym x⊓y≡z = m≤n⇒m⊓o≤n y (≤-refl)
minmax-absorb : {x y : } x (x y) x
minmax-absorb {x} {y} = ≤-antisym x⊓x⊔y≤x (helper x⊓x≤x⊓x⊔y (⊓-idem x))
where
x⊓x⊔y≤x = min-bound₁ {x} {x y} {x (x y)} refl
x⊓x≤x⊓x⊔y = ⊓-mono-≤ {x} {x} ≤-refl (max-bound₁ {x} {y} {x y} refl)
-- >:(
helper : x x x (x y) x x x x x (x y)
helper x⊓x≤x⊓x⊔y x⊓x≡x rewrite x⊓x≡x = x⊓x≤x⊓x⊔y
maxmin-absorb : {x y : } x (x y) x
maxmin-absorb {x} {y} = ≤-antisym (helper x⊔x⊓y≤x⊔x (⊔-idem x)) x≤x⊔x⊓y
where
x≤x⊔x⊓y = max-bound₁ {x} {x y} {x (x y)} refl
x⊔x⊓y≤x⊔x = ⊔-mono-≤ {x} {x} ≤-refl (min-bound₁ {x} {y} {x y} refl)
-- >:(
helper : x (x y) x x x x x x (x y) x
helper x⊔x⊓y≤x⊔x x⊔x≡x rewrite x⊔x≡x = x⊔x⊓y≤x⊔x
NatIsLattice : IsLattice _≡_ _⊔_ _⊓_
NatIsLattice = record
{ joinSemilattice = NatIsMaxSemilattice
; meetSemilattice = NatIsMinSemilattice
; absorb-⊔-⊓ = λ x y maxmin-absorb {x} {y}
; absorb-⊓-⊔ = λ x y minmax-absorb {x} {y}
}
module ForProd {a} {A B : Set a}
(_≈₁_ : A A Set a) (_≈₂_ : B B Set a)
(_⊔₁_ : A A A) (_⊓₁_ : A A A)
(_⊔₂_ : B B B) (_⊓₂_ : B B B)
(lA : IsLattice A _≈₁_ _⊔₁_ _⊓₁_) (lB : IsLattice B _≈₂_ _⊔₂_ _⊓₂_) where
private
module ProdJoin = IsSemilatticeInstances.ForProd _≈₁_ _≈₂_ _⊔₁_ _⊔₂_ (IsLattice.joinSemilattice lA) (IsLattice.joinSemilattice lB)
module ProdMeet = IsSemilatticeInstances.ForProd _≈₁_ _≈₂_ _⊓₁_ _⊓₂_ (IsLattice.meetSemilattice lA) (IsLattice.meetSemilattice lB)
infix 4 _≈_
infixl 20 _⊔_
_≈_ : (A × B) (A × B) Set a
(a₁ , b₁) (a₂ , b₂) = (a₁ ≈₁ a₂) × (b₁ ≈₂ b₂)
_⊔_ : (A × B) (A × B) (A × B)
(a₁ , b₁) (a₂ , b₂) = (a₁ ⊔₁ a₂ , b₁ ⊔₂ b₂)
_⊓_ : (A × B) (A × B) (A × B)
(a₁ , b₁) (a₂ , b₂) = (a₁ ⊓₁ a₂ , b₁ ⊓₂ b₂)
open Eq
open Data.Product
private
absorb-⊔-⊓ : (p₁ p₂ : A × B) p₁ (p₁ p₂) p₁
absorb-⊔-⊓ (a₁ , b₁) (a₂ , b₂) =
( IsLattice.absorb-⊔-⊓ lA a₁ a₂
, IsLattice.absorb-⊔-⊓ lB b₁ b₂
)
absorb-⊓-⊔ : (p₁ p₂ : A × B) p₁ (p₁ p₂) p₁
absorb-⊓-⊔ (a₁ , b₁) (a₂ , b₂) =
( IsLattice.absorb-⊓-⊔ lA a₁ a₂
, IsLattice.absorb-⊓-⊔ lB b₁ b₂
)
ProdIsLattice : IsLattice (A × B) _≈_ _⊔_ _⊓_
ProdIsLattice = record
{ joinSemilattice = ProdJoin.ProdIsSemilattice
; meetSemilattice = ProdMeet.ProdIsSemilattice
; absorb-⊔-⊓ = absorb-⊔-⊓
; absorb-⊓-⊔ = absorb-⊓-⊔
}