agda-spa/Lattice/Builder.agda
Danila Fedorin 14f1494fc3 Provide a definition of partial congruence
Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>
2025-07-22 18:01:48 +02:00

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module Lattice.Builder where
open import Lattice
open import Equivalence
open import Data.Maybe as Maybe using (Maybe; just; nothing; _>>=_; maybe)
open import Data.Maybe.Properties using (just-injective)
open import Data.Unit using (; tt)
open import Data.List.NonEmpty using (List⁺; tail; toList) renaming (_∷_ to _∷⁺_)
open import Data.List using (List; _∷_; [])
open import Data.Sum using (_⊎_; inj₁; inj₂)
open import Data.Product using (Σ; _,_)
open import Data.Empty using (⊥; ⊥-elim)
open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl; sym; trans; cong; subst)
open import Agda.Primitive using (lsuc; Level) renaming (_⊔_ to _⊔_)
maybe-injection : {a} {A : Set a} (x : A) just x nothing
maybe-injection x ()
data lift-≈ {a} {A : Set a} (_≈_ : A A Set a) : Maybe A Maybe A Set a where
≈-just : {a₁ a₂ : A} a₁ a₂ lift-≈ _≈_ (just a₁) (just a₂)
≈-nothing : lift-≈ _≈_ nothing nothing
lift-≈-map : {a b} {A : Set a} {B : Set b} (f : A B)
(_≈ᵃ_ : A A Set a) (_≈ᵇ_ : B B Set b)
( a₁ a₂ a₁ ≈ᵃ a₂ f a₁ ≈ᵇ f a₂)
m₁ m₂ lift-≈ _≈ᵃ_ m₁ m₂ lift-≈ _≈ᵇ_ (Maybe.map f m₁) (Maybe.map f m₂)
lift-≈-map f _≈ᵃ_ _≈ᵇ_ ≈ᵃ→≈ᵇ (just a₁) (just a₂) (≈-just a₁≈a₂) = ≈-just (≈ᵃ→≈ᵇ a₁ a₂ a₁≈a₂)
lift-≈-map f _≈ᵃ_ _≈ᵇ_ ≈ᵃ→≈ᵇ nothing nothing ≈-nothing = ≈-nothing
instance
lift-≈-Equivalence : {a} {A : Set a} {_≈_ : A A Set a} {{isEquivalence : IsEquivalence A _≈_}} IsEquivalence (Maybe A) (lift-≈ _≈_)
lift-≈-Equivalence {{isEquivalence}} = record
{ ≈-trans =
(λ { (≈-just a₁≈a₂) (≈-just a₂≈a₃) ≈-just (IsEquivalence.≈-trans isEquivalence a₁≈a₂ a₂≈a₃)
; ≈-nothing ≈-nothing ≈-nothing
})
; ≈-sym =
(λ { (≈-just a₁≈a₂) ≈-just (IsEquivalence.≈-sym isEquivalence a₁≈a₂)
; ≈-nothing ≈-nothing
})
; ≈-refl = λ { {just a} ≈-just (IsEquivalence.≈-refl isEquivalence)
; {nothing} ≈-nothing
}
}
PartialCong : {a} {A : Set a} (_≈_ : A A Set a) (_⊗_ : A A Maybe A) Set a
PartialCong {a} {A} _≈_ _⊗_ = {a₁ a₂ a₃ a₄} a₁ a₂ a₃ a₄ lift-≈ _≈_ (a₁ a₃) (a₂ a₄)
PartialAssoc : {a} {A : Set a} (_≈_ : A A Set a) (_⊗_ : A A Maybe A) Set a
PartialAssoc {a} {A} _≈_ _⊗_ = (x y z : A) lift-≈ _≈_ ((x y) >>= (_⊗ z)) ((y z) >>= (x ⊗_))
PartialComm : {a} {A : Set a} (_≈_ : A A Set a) (_⊗_ : A A Maybe A) Set a
PartialComm {a} {A} _≈_ _⊗_ = (x y : A) lift-≈ _≈_ (x y) (y x)
PartialIdemp : {a} {A : Set a} (_≈_ : A A Set a) (_⊗_ : A A Maybe A) Set a
PartialIdemp {a} {A} _≈_ _⊗_ = (x : A) lift-≈ _≈_ (x x) (just x)
data Trivial a : Set a where
instance
mkTrivial : Trivial a
data Empty a : Set a where
record IsPartialSemilattice {a} {A : Set a}
(_≈_ : A A Set a)
(_⊔?_ : A A Maybe A) : Set a where
_≈?_ : Maybe A Maybe A Set a
_≈?_ = lift-≈ _≈_
_≼_ : A A Set a
_≼_ x y = (x ⊔? y) ≈? (just y)
field
≈-equiv : IsEquivalence A _≈_
≈-⊔-cong : PartialCong _≈_ _⊔?_
⊔-assoc : PartialAssoc _≈_ _⊔?_
⊔-comm : PartialComm _≈_ _⊔?_
⊔-idemp : PartialIdemp _≈_ _⊔?_
open IsEquivalence ≈-equiv public
open IsEquivalence (lift-≈-Equivalence {{≈-equiv}}) public using ()
renaming (≈-trans to ≈?-trans; ≈-sym to ≈?-sym; ≈-refl to ≈?-refl)
≈-≼-cong : {a₁ a₂ a₃ a₄} a₁ a₂ a₃ a₄ a₁ a₃ a₂ a₄
≈-≼-cong {a₁} {a₂} {a₃} {a₄} a₁≈a₂ a₃≈a₄ a₁≼a₃ = ≈?-trans (≈?-trans (≈?-sym (≈-⊔-cong a₁≈a₂ a₃≈a₄)) a₁≼a₃) (≈-just a₃≈a₄)
-- curious: similar property (properties?) to partial commutative monoids (PCMs)
-- from Iris.
≼-partialˡ : {a a₁ a₂} a₁ a₂ (a ⊔? a₁) nothing (a ⊔? a₂) nothing
≼-partialˡ {a} {a₁} {a₂} a₁≼a₂ a⊔a₁≡nothing
with a₁ ⊔? a₂ | a₁≼a₂ | a ⊔? a₁ | a⊔a₁≡nothing | ⊔-assoc a a₁ a₂
... | just a₁⊔a₂ | ≈-just a₁⊔a₂≈a₂ | nothing | refl | aa₁⊔a₂≈a⊔a₁a₂
with a ⊔? a₁⊔a₂ | aa₁⊔a₂≈a⊔a₁a₂ | a ⊔? a₂ | ≈-⊔-cong (≈-refl {a = a}) a₁⊔a₂≈a₂
... | nothing | ≈-nothing | nothing | ≈-nothing = refl
≼-partialʳ : {a₁ a₂ a} a₁ a₂ (a₁ ⊔? a) nothing (a₂ ⊔? a) nothing
≼-partialʳ {a₁} {a₂} {a} a₁≼a₂ a₁⊔a≡nothing
with a₁ ⊔? a | a ⊔? a₁ | a₁⊔a≡nothing | ⊔-comm a₁ a | ≼-partialˡ {a} {a₁} {a₂} a₁≼a₂
... | nothing | nothing | refl | ≈-nothing | refl⇒a⊔a₂=nothing
with a₂ ⊔? a | a ⊔? a₂ | ⊔-comm a₂ a | refl⇒a⊔a₂=nothing refl
... | nothing | nothing | ≈-nothing | refl = refl
≼-refl : (x : A) x x
≼-refl x = ⊔-idemp x
≼-refl' : {a₁ a₂ : A} a₁ a₂ a₁ a₂
≼-refl' {a₁} {a₂} a₁≈a₂ = ≈-≼-cong ≈-refl a₁≈a₂ (≼-refl a₁)
x⊔?x≼x : (x : A) maybe (λ x⊔x x⊔x x) (Empty a) (x ⊔? x)
x⊔?x≼x x
with x ⊔? x | ⊔-idemp x
... | just x⊔x | ≈-just x⊔x≈x = ≈-≼-cong (≈-sym x⊔x≈x) ≈-refl (≼-refl x)
x≼x⊔?y : (x y : A) maybe (λ x⊔y x x⊔y) (Trivial a) (x ⊔? y)
x≼x⊔?y x y
with x ⊔? y in x⊔?y= | x ⊔? x | ⊔-idemp x | ⊔-assoc x x y | x⊔?x≼x x
... | nothing | _ | _ | _ | _ = mkTrivial
... | just x⊔y | just x⊔x | ≈-just x⊔x≈x | ⊔-assoc-xxy | x⊔x≼x
with x⊔x ⊔? y in xx⊔?y= | x ⊔? x⊔y
... | nothing | nothing =
⊥-elim (maybe-injection _ (trans (sym x⊔?y=) (≼-partialʳ x⊔x≼x xx⊔?y=)))
... | just xx⊔y | just x⊔xy rewrite (sym xx⊔?y=) rewrite (sym x⊔?y=) =
≈?-trans (≈?-sym ⊔-assoc-xxy) (≈-⊔-cong x⊔x≈x (≈-refl {a = y}))
record HasAbsorbingElement : Set a where
field
x : A
x-absorbˡ : (a : A) (x ⊔? a) ≈? just x
x-absorbʳ : (a : A) (a ⊔? x) ≈? just x
x-absorbʳ a = ≈?-trans (⊔-comm a x) (x-absorbˡ a)
not-partial : (a₁ a₂ : A) Σ A (λ a₃ (a₁ ⊔? a₂) just a₃)
not-partial a₁ a₂
with a₁ ⊔? a₂ | ≼-partialˡ {a = a₁} (x-absorbʳ a₂)
... | just a₁⊔a₂ | _ = (a₁⊔a₂ , refl)
... | nothing | refl⇒a₁⊔?x=nothing
with a₁ ⊔? x | refl⇒a₁⊔?x=nothing refl | x-absorbʳ a₁
... | nothing | refl | ()
record IsPartialLattice {a} {A : Set a}
(_≈_ : A A Set a)
(_⊔?_ : A A Maybe A)
(_⊓?_ : A A Maybe A) : Set a where
field
{{partialJoinSemilattice}} : IsPartialSemilattice _≈_ _⊔?_
{{partialMeetSemilattice}} : IsPartialSemilattice _≈_ _⊓?_
absorb-⊔-⊓ : (x y : A) maybe (λ x⊓y lift-≈ _≈_ (x ⊔? x⊓y) (just x)) (Trivial _) (x ⊓? y)
absorb-⊓-⊔ : (x y : A) maybe (λ x⊔y lift-≈ _≈_ (x ⊓? x⊔y) (just x)) (Trivial _) (x ⊔? y)
open IsPartialSemilattice partialJoinSemilattice
renaming (HasAbsorbingElement to HasGreatestElement)
public
open IsPartialSemilattice partialMeetSemilattice using ()
renaming
( HasAbsorbingElement to HasLeastElement
; ≈-⊔-cong to ≈-⊓-cong
; ⊔-assoc to ⊓-assoc
; ⊔-comm to ⊓-comm
; ⊔-idemp to ⊓-idemp
)
public
record PartialLattice {a} (A : Set a) : Set (lsuc a) where
field
_≈_ : A A Set a
_⊔?_ : A A Maybe A
_⊓?_ : A A Maybe A
{{isPartialLattice}} : IsPartialLattice _≈_ _⊔?_ _⊓?_
open IsPartialLattice isPartialLattice public
greatest-⊓-identʳ : (le : HasGreatestElement) (x : A)
(x ⊓? HasGreatestElement.x le) ≈? (just x)
greatest-⊓-identʳ le x
with x ⊔? (HasGreatestElement.x le) | HasGreatestElement.x-absorbʳ le x | absorb-⊓-⊔ x (HasGreatestElement.x le)
... | just x⊔greatest | ≈-just x⊔greatest≈greatest | x⊓xgreatest≈?x = ≈?-trans (≈?-sym (≈-⊓-cong (≈-refl {a = x}) x⊔greatest≈greatest)) x⊓xgreatest≈?x
greatest-⊓-identˡ : (le : HasGreatestElement) (x : A)
(HasGreatestElement.x le ⊓? x) ≈? (just x)
greatest-⊓-identˡ le x = ≈?-trans (⊓-comm (HasGreatestElement.x le) x) (greatest-⊓-identʳ le x)
least-⊔-identʳ : (le : HasLeastElement) (x : A)
(x ⊔? HasLeastElement.x le) ≈? (just x)
least-⊔-identʳ le x
with x ⊓? (HasLeastElement.x le) | HasLeastElement.x-absorbʳ le x | absorb-⊔-⊓ x (HasLeastElement.x le)
... | just x⊓least | ≈-just x⊓least≈least | x⊔xleast≈?x = ≈?-trans (≈?-sym (≈-⊔-cong (≈-refl {a = x}) x⊓least≈least)) x⊔xleast≈?x
least-⊔-identˡ : (le : HasLeastElement) (x : A)
(HasLeastElement.x le ⊔? x) ≈? (just x)
least-⊔-identˡ le x = ≈?-trans (⊔-comm (HasLeastElement.x le) x) (least-⊔-identʳ le x)
record PartialLatticeType (a : Level) : Set (lsuc a) where
field
EltType : Set a
{{partialLattice}} : PartialLattice EltType
open PartialLattice partialLattice public
Layer : (a : Level) Set (lsuc a)
Layer a = List⁺ (PartialLatticeType a)
data LayerLeast {a} : Layer a Set (lsuc a) where
instance
MkLayerLeast : {T : Set a}
{{ partialLattice : PartialLattice T }}
{{ hasLeast : PartialLattice.HasLeastElement partialLattice }}
LayerLeast (record { EltType = T; partialLattice = partialLattice } ∷⁺ [])
data LayerGreatest {a} : Layer a Set (lsuc a) where
instance
MkLayerGreatest : {T : Set a}
{{ partialLattice : PartialLattice T }}
{{ hasGreatest : PartialLattice.HasGreatestElement partialLattice }}
LayerGreatest (record { EltType = T; partialLattice = partialLattice } ∷⁺ [])
interleaved mutual
data Layers a : Set (lsuc a)
head : {a} Layers a Layer a
data Layers where
single : Layer a Layers a
add-via-least : (l : Layer a) {{ least : LayerLeast l }} (ls : Layers a) Layers a
add-via-greatest : (l : Layer a) (ls : Layers a) {{ greatest : LayerGreatest (head ls) }} Layers a
head (single l) = l
head (add-via-greatest l _) = l
head (add-via-least l _) = l
ListValue : {a} List (PartialLatticeType a) Set a
ListValue [] = Empty _
ListValue (plt plts) = PartialLatticeType.EltType plt ListValue plts
-- Define LayerValue and Path' as functions to avoid increasing the universe level.
-- Path' in particular needs to be at the same level as the other lattices
-- in the builder to ensure composability.
LayerValue : {a} Layer a Set a
LayerValue l⁺ = ListValue (toList l⁺)
Path' : {a} Layers a Set a
Path' (single l) = LayerValue l
Path' (add-via-least l ls) = LayerValue l Path' ls
Path' (add-via-greatest l ls) = LayerValue l Path' ls
record Path {a} (Ls : Layers a) : Set a where
constructor MkPath
field path : Path' Ls
valueAtHead : {a} (ls : Layers a) (lv : LayerValue (head ls)) Path' ls
valueAtHead (single _) lv = lv
valueAtHead (add-via-least _ _) lv = inj₁ lv
valueAtHead (add-via-greatest _ _) lv = inj₁ lv
CombineForPLT : a Set (lsuc a)
CombineForPLT a = (plt : PartialLatticeType a) PartialLatticeType.EltType plt PartialLatticeType.EltType plt Maybe (PartialLatticeType.EltType plt)
lvCombine : {a} (f : CombineForPLT a) (l : List (PartialLatticeType a)) (lv₁ lv₂ : ListValue l) Maybe (ListValue l)
lvCombine _ [] _ _ = nothing
lvCombine f (plt plts) (inj₁ v₁) (inj₁ v₂) = Maybe.map inj₁ (f plt v₁ v₂)
lvCombine f (_ plts) (inj₂ lv₁) (inj₂ lv₂) = Maybe.map inj₂ (lvCombine f plts lv₁ lv₂)
lvCombine _ (_ plts) (inj₁ _) (inj₂ _) = nothing
lvCombine _ (_ plts) (inj₂ _) (inj₁ _) = nothing
lvJoin : {a} (l : List (PartialLatticeType a)) (lv₁ lv₂ : ListValue l) Maybe (ListValue l)
lvJoin = lvCombine PartialLatticeType._⊔?_
lvMeet : {a} (l : List (PartialLatticeType a)) (lv₁ lv₂ : ListValue l) Maybe (ListValue l)
lvMeet = lvCombine PartialLatticeType._⊓?_
pathJoin' : {a} (Ls : Layers a) (p₁ p₂ : Path' Ls) Maybe (Path' Ls)
pathJoin' (single l) lv₁ lv₂ = lvJoin (toList l) lv₁ lv₂
pathJoin' (add-via-least l ls) (inj₁ lv₁) (inj₁ lv₂) = Maybe.map inj₁ (lvJoin (toList l) lv₁ lv₂)
pathJoin' (add-via-least l ls) (inj₁ lv₁) (inj₂ p₂) = just (inj₁ lv₁)
pathJoin' (add-via-least l ls) (inj₂ p₁) (inj₁ lv₂) = just (inj₁ lv₂)
pathJoin' (add-via-least l@(plt ∷⁺ []) {{MkLayerLeast {{hasLeast = hasLeast}}}} ls) (inj₂ p₁) (inj₂ p₂)
with pathJoin' ls p₁ p₂
... | just p = just (inj₂ p)
... | nothing = just (inj₁ (inj₁ (IsPartialSemilattice.HasAbsorbingElement.x hasLeast)))
pathJoin' (add-via-greatest l ls) (inj₁ lv₁) (inj₁ lv₂) = Maybe.map inj₁ (lvJoin (toList l) lv₁ lv₂)
pathJoin' (add-via-greatest l ls) (inj₁ lv₁) (inj₂ p₂) = just (inj₁ lv₁)
pathJoin' (add-via-greatest l ls) (inj₂ p₁) (inj₁ lv₂) = just (inj₁ lv₂)
pathJoin' (add-via-greatest l ls {{greatest}}) (inj₂ p₁) (inj₂ p₂) = Maybe.map inj₂ (pathJoin' ls p₁ p₂) -- not our job to provide the least element here. If there was a "greatest" there, recursion would've found it (?)
pathMeet' : {a} (Ls : Layers a) (p₁ p₂ : Path' Ls) Maybe (Path' Ls)
pathMeet' (single l) lv₁ lv₂ = lvMeet (toList l) lv₁ lv₂
pathMeet' (add-via-least l ls) (inj₁ lv₁) (inj₁ lv₂) = Maybe.map inj₁ (lvMeet (toList l) lv₁ lv₂)
pathMeet' (add-via-least l ls) (inj₁ lv₁) (inj₂ p₂) = just (inj₂ p₂)
pathMeet' (add-via-least l ls) (inj₂ p₁) (inj₁ lv₂) = just (inj₂ p₁)
pathMeet' (add-via-least l ls) (inj₂ p₁) (inj₂ p₂) = Maybe.map inj₂ (pathMeet' ls p₁ p₂)
pathMeet' (add-via-greatest l ls {{greatest}}) (inj₁ lv₁) (inj₁ lv₂)
with lvMeet (toList l) lv₁ lv₂
... | just lv = just (inj₁ lv)
... | nothing
with head ls | greatest | valueAtHead ls
... | _ | MkLayerGreatest {{hasGreatest = hasGreatest}} | vah
= just (inj₂ (vah (inj₁ (IsPartialSemilattice.HasAbsorbingElement.x hasGreatest))))
pathMeet' (add-via-greatest l ls) (inj₁ lv₁) (inj₂ p₂) = just (inj₂ p₂)
pathMeet' (add-via-greatest l ls) (inj₂ p₁) (inj₁ lv₂) = just (inj₂ p₁)
pathMeet' (add-via-greatest l ls) (inj₂ p₁) (inj₂ p₂) = Maybe.map inj₂ (pathMeet' ls p₁ p₂)
eqL : {a} (L : List (PartialLatticeType a)) ListValue L ListValue L Set a
eqL [] ()
eqL (plt plts) (inj₁ v₁ ) (inj₁ v₂) = PartialLattice._≈_ (PartialLatticeType.partialLattice plt) v₁ v₂
eqL (plt plts) (inj₂ v₁ ) (inj₂ v₂) = eqL plts v₁ v₂
eqL (plt plts) (inj₁ _) (inj₂ _) = Empty _
eqL (plt plts) (inj₂ _) (inj₁ _) = Empty _
eqL-trans : {a} (L : List (PartialLatticeType a)) {lv₁ lv₂ lv₃ : ListValue L} eqL L lv₁ lv₂ eqL L lv₂ lv₃ eqL L lv₁ lv₃
eqL-trans [] {()}
eqL-trans (plt plts) {inj₁ v₁} {inj₁ v₂} {inj₁ v₃} v₁≈v₂ v₂≈v₃ = PartialLatticeType.≈-trans plt v₁≈v₂ v₂≈v₃
eqL-trans (plt plts) {inj₂ lv₁} {inj₂ lv₂} {inj₂ lv₃} lv₁≈lv₂ lv₂≈lv₃ = eqL-trans plts lv₁≈lv₂ lv₂≈lv₃
eqL-sym : {a} (L : List (PartialLatticeType a)) {lv₁ lv₂ : ListValue L} eqL L lv₁ lv₂ eqL L lv₂ lv₁
eqL-sym [] {()}
eqL-sym (plt plts) {inj₁ v₁} {inj₁ v₂} v₁≈v₂ = PartialLatticeType.≈-sym plt v₁≈v₂
eqL-sym (plt plts) {inj₂ lv₁} {inj₂ lv₂} lv₁≈lv₂ = eqL-sym plts lv₁≈lv₂
eqL-refl : {a} (L : List (PartialLatticeType a)) (lv : ListValue L) eqL L lv lv
eqL-refl [] ()
eqL-refl (plt plts) (inj₁ v) = IsEquivalence.≈-refl (PartialLatticeType.≈-equiv plt)
eqL-refl (plt plts) (inj₂ v) = eqL-refl plts v
instance
eqL-Equivalence : {a} {L : List (PartialLatticeType a)} IsEquivalence (ListValue L) (eqL L)
eqL-Equivalence {L = L} = record
{ ≈-trans = eqL-trans L
; ≈-sym = eqL-sym L
; ≈-refl = λ {lv} eqL-refl L lv
}
eqLv : {a} (L : Layer a) LayerValue L LayerValue L Set a
eqLv L = eqL (toList L)
eqLv-trans : {a} (L : Layer a) {lv₁ lv₂ lv₃ : LayerValue L} eqLv L lv₁ lv₂ eqLv L lv₂ lv₃ eqLv L lv₁ lv₃
eqLv-trans L {lv₁} {lv₂} {lv₃} = eqL-trans (toList L) {lv₁} {lv₂} {lv₃}
eqLv-sym : {a} (L : Layer a) {lv₁ lv₂ : LayerValue L} eqLv L lv₁ lv₂ eqLv L lv₂ lv₁
eqLv-sym L {lv₁} {lv₂} = eqL-sym (toList L) {lv₁} {lv₂}
eqLv-refl : {a} (L : Layer a) (lv : LayerValue L) eqLv L lv lv
eqLv-refl L = eqL-refl (toList L)
instance
eqLv-Equivalence : {a} {L : Layer a} IsEquivalence (LayerValue L) (eqLv L)
eqLv-Equivalence {L = L} = record
{ ≈-trans = λ {lv₁} {lv₂} {lv₃} eqLv-trans L {lv₁} {lv₂} {lv₃}
; ≈-sym = λ {lv₁} {lv₂} eqLv-sym L {lv₁} {lv₂}
; ≈-refl = λ {lv} eqLv-refl L lv
}
eqPath' : {a} (Ls : Layers a) Path' Ls Path' Ls Set a
eqPath' (single l) lv₁ lv₂ = eqLv l lv₁ lv₂
eqPath' (add-via-least l ls) (inj₁ lv₁) (inj₁ lv₂) = eqLv l lv₁ lv₂
eqPath' (add-via-least l ls) (inj₂ p₁) (inj₂ p₂) = eqPath' ls p₁ p₂
eqPath' (add-via-least l ls) (inj₁ lv₁) (inj₂ p₂) = Empty _
eqPath' (add-via-least l ls) (inj₂ p₁) (inj₁ lv₂) = Empty _
eqPath' (add-via-greatest l ls) (inj₁ lv₁) (inj₁ lv₂) = eqLv l lv₁ lv₂
eqPath' (add-via-greatest l ls) (inj₂ p₁) (inj₂ p₂) = eqPath' ls p₁ p₂
eqPath' (add-via-greatest l ls) (inj₁ lv₁) (inj₂ p₂) = Empty _
eqPath' (add-via-greatest l ls) (inj₂ p₁) (inj₁ lv₂) = Empty _
eqPath'-trans : {a} (Ls : Layers a) {p₁ p₂ p₃ : Path' Ls} eqPath' Ls p₁ p₂ eqPath' Ls p₂ p₃ eqPath' Ls p₁ p₃
eqPath'-trans (single l) {lv₁} {lv₂} {lv₃} lv₁≈lv₂ lv₂≈lv₃ = eqLv-trans l {lv₁} {lv₂} {lv₃} lv₁≈lv₂ lv₂≈lv₃
eqPath'-trans (add-via-least l ls) {inj₁ lv₁} {inj₁ lv₂} {inj₁ lv₃} lv₁≈lv₂ lv₂≈lv₃ = eqLv-trans l {lv₁} {lv₂} {lv₃} lv₁≈lv₂ lv₂≈lv₃
eqPath'-trans (add-via-least l ls) {inj₂ p₁} {inj₂ p₂} {inj₂ p₃} p₁≈p₂ p₂≈p₃ = eqPath'-trans ls p₁≈p₂ p₂≈p₃
eqPath'-trans (add-via-greatest l ls) {inj₁ lv₁} {inj₁ lv₂} {inj₁ lv₃} lv₁≈lv₂ lv₂≈lv₃ = eqLv-trans l {lv₁} {lv₂} {lv₃} lv₁≈lv₂ lv₂≈lv₃
eqPath'-trans (add-via-greatest l ls) {inj₂ p₁} {inj₂ p₂} {inj₂ p₃} p₁≈p₂ p₂≈p₃ = eqPath'-trans ls p₁≈p₂ p₂≈p₃
eqPath'-sym : {a} (Ls : Layers a) {p₁ p₂ : Path' Ls} eqPath' Ls p₁ p₂ eqPath' Ls p₂ p₁
eqPath'-sym (single l) {lv₁} {lv₂} lv₁≈lv₂ = eqLv-sym l {lv₁} {lv₂} lv₁≈lv₂
eqPath'-sym (add-via-least l ls) {inj₁ lv₁} {inj₁ lv₂}lv₁≈lv₂ = eqLv-sym l {lv₁} {lv₂} lv₁≈lv₂
eqPath'-sym (add-via-least l ls) {inj₂ p₁} {inj₂ p₂} p₁≈p₂ = eqPath'-sym ls p₁≈p₂
eqPath'-sym (add-via-greatest l ls) {inj₁ lv₁} {inj₁ lv₂}lv₁≈lv₂ = eqLv-sym l {lv₁} {lv₂} lv₁≈lv₂
eqPath'-sym (add-via-greatest l ls) {inj₂ p₁} {inj₂ p₂} p₁≈p₂ = eqPath'-sym ls p₁≈p₂
eqPath'-refl : {a} (Ls : Layers a) (p : Path' Ls) eqPath' Ls p p
eqPath'-refl (single l) lv = eqLv-refl l lv
eqPath'-refl (add-via-least l ls) (inj₁ lv) = eqLv-refl l lv
eqPath'-refl (add-via-least l ls) (inj₂ p) = eqPath'-refl ls p
eqPath'-refl (add-via-greatest l ls) (inj₁ lv) = eqLv-refl l lv
eqPath'-refl (add-via-greatest l ls) (inj₂ p) = eqPath'-refl ls p
instance
eqPath'-Equivalence : {a} {Ls : Layers a} IsEquivalence (Path' Ls) (eqPath' Ls)
eqPath'-Equivalence {Ls = Ls} = record
{ ≈-trans = eqPath'-trans Ls
; ≈-sym = eqPath'-sym Ls
; ≈-refl = λ {x} eqPath'-refl Ls x
}
-- Now that we can compare paths for "equality", we can state and
-- prove theorems such as commutativity and idempotence.
data Expr {a} (A : Set a) : Set a where
`_ : A Expr A
__ : Expr A Expr A Expr A
map : {a b} {A : Set a} {B : Set b} (f : A B) Expr A Expr B
map f (` x) = ` (f x)
map f (e₁ e₂) = map f e₁ map f e₂
eval : {a} {A : Set a} (_⊔?_ : A A Maybe A) (e : Expr A) Maybe A
eval _⊔?_ (` x) = just x
eval _⊔?_ (e₁ e₂) = (eval _⊔?_ e₁) >>= (λ v₁ (eval _⊔?_ e₂) >>= (v₁ ⊔?_))
-- a function is "partially sub-homomorphic" for some subset of B (image of f) if
-- for (f A), it preserves the structure of operations _⊕ on A in B.
PartiallySubHomo : {a b} {A : Set a} {B : Set b} (f : A B) (_⊕_ : A A Maybe A) (_⊗_ : B B Maybe B) Set (a ⊔ℓ b)
PartiallySubHomo {A = A} f _⊕_ _⊗_ = (a₁ a₂ : A) (f a₁ f a₂) Maybe.map f (a₁ a₂)
-- this evaluation property, which depends on PartiallySubHomo, effectively makes
-- it easier to talk about compound operations and the preservation of their
-- structure when _⊗_ is PartiallySubHomo.
--
-- i.e., if (f a) ⊗ (f b) = Maybe.map f (a ⊕ b), then we can make similar claims about f (a ⊕ b ⊕ c)
eval-subHomo : {a b} {A : Set a} {B : Set b} (f : A B) (_⊕_ : A A Maybe A) (_⊗_ : B B Maybe B) (e : Expr A)
PartiallySubHomo f _⊕_ _⊗_
eval _⊗_ (map f e) Maybe.map f (eval _⊕_ e)
eval-subHomo f _⊕_ _⊗_ (` _) psh = refl
eval-subHomo f _⊕_ _⊗_ (e₁ e₂) psh
rewrite eval-subHomo f _⊕_ _⊗_ e₁ psh rewrite eval-subHomo f _⊕_ _⊗_ e₂ psh
with eval _⊕_ e₁ | eval _⊕_ e₂
... | just x₁ | just x₂ = psh x₁ x₂
... | nothing | nothing = refl
... | just x₁ | nothing = refl
... | nothing | just x₂ = refl
lvCombine-homo₁ : {a} plt plts (f : CombineForPLT a) (e : Expr (PartialLatticeType.EltType plt)) eval (lvCombine f (plt plts)) (map inj₁ e) Maybe.map inj₁ (eval (f plt) e)
lvCombine-homo₁ plt plts f e = eval-subHomo inj₁ (f plt) (lvCombine f (plt plts)) e (λ a₁ a₂ refl)
lvCombine-homo₂ : {a} plt plts (f : CombineForPLT a) (e : Expr (ListValue plts)) eval (lvCombine f (plt plts)) (map inj₂ e) Maybe.map inj₂ (eval (lvCombine f plts) e)
lvCombine-homo₂ plt plts f e = eval-subHomo inj₂ (lvCombine f plts) (lvCombine f (plt plts)) e (λ a₁ a₂ refl)
pathJoin'-homo-least₁ : {a} (l : Layer a) (ls : Layers a) least (e : Expr (LayerValue l)) eval (pathJoin' (add-via-least l {{least}} ls)) (map inj₁ e) Maybe.map inj₁ (eval (lvJoin (toList l)) e)
pathJoin'-homo-least₁ l ls least e = eval-subHomo inj₁ (lvJoin (toList l)) (pathJoin' (add-via-least l {{least}} ls)) e (λ a₁ a₂ refl)
pathJoin'-homo-greatest₁ : {a} (l : Layer a) (ls : Layers a) greatest (e : Expr (LayerValue l)) eval (pathJoin' (add-via-greatest l ls {{greatest}})) (map inj₁ e) Maybe.map inj₁ (eval (lvJoin (toList l)) e)
pathJoin'-homo-greatest₁ l ls greatest e = eval-subHomo inj₁ (lvJoin (toList l)) (pathJoin' (add-via-greatest l ls {{greatest}})) e (λ a₁ a₂ refl)
pathJoin'-homo-greatest₂ : {a} (l : Layer a) (ls : Layers a) greatest (e : Expr (Path' ls)) eval (pathJoin' (add-via-greatest l ls {{greatest}})) (map inj₂ e) Maybe.map inj₂ (eval (pathJoin' ls) e)
pathJoin'-homo-greatest₂ l ls greatest e = eval-subHomo inj₂ (pathJoin' ls) (pathJoin' (add-via-greatest l ls {{greatest}})) e (λ a₁ a₂ refl)
lvCombine-assoc : {a} (f : CombineForPLT a)
( plt PartialAssoc (PartialLatticeType._≈_ plt) (f plt))
(L : List (PartialLatticeType a))
PartialAssoc (eqL L) (lvCombine f L)
lvCombine-assoc f f-assoc L@(plt plts) (inj₁ v₁) (inj₁ v₂) (inj₁ v₃)
rewrite lvCombine-homo₁ plt plts f (((` v₁) (` v₂)) (` v₃))
rewrite lvCombine-homo₁ plt plts f ((` v₁) ((` v₂) (` v₃)))
= lift-≈-map inj₁ _ _ (λ _ _ x x) _ _ (f-assoc plt v₁ v₂ v₃)
lvCombine-assoc f f-assoc L@(plt plts) (inj₂ _) (inj₁ v₂) (inj₁ v₃)
with f plt v₂ v₃
... | just _ = ≈-nothing
... | nothing = ≈-nothing
lvCombine-assoc f f-assoc L@(plt plts) (inj₁ _) (inj₂ _) (inj₁ _) = ≈-nothing
lvCombine-assoc f f-assoc L@(plt plts) (inj₂ lv₁) (inj₂ lv₂) (inj₁ _)
with lvCombine f plts lv₁ lv₂
... | just _ = ≈-nothing
... | nothing = ≈-nothing
lvCombine-assoc f f-assoc L@(plt plts) (inj₁ v₁) (inj₁ v₂) (inj₂ _)
with f plt v₁ v₂
... | just _ = ≈-nothing
... | nothing = ≈-nothing
lvCombine-assoc f f-assoc L@(plt plts) (inj₂ _) (inj₁ _) (inj₂ _) = ≈-nothing
lvCombine-assoc f f-assoc L@(plt plts) (inj₁ _) (inj₂ lv₂) (inj₂ lv₃)
with lvCombine f plts lv₂ lv₃
... | just _ = ≈-nothing
... | nothing = ≈-nothing
lvCombine-assoc f f-assoc L@(plt plts) (inj₂ lv₁) (inj₂ lv₂) (inj₂ lv₃)
rewrite lvCombine-homo₂ plt plts f (((` lv₁) (` lv₂)) (` lv₃))
rewrite lvCombine-homo₂ plt plts f ((` lv₁) ((` lv₂) (` lv₃)))
= lift-≈-map inj₂ _ _ (λ _ _ x x) _ _ (lvCombine-assoc f f-assoc plts lv₁ lv₂ lv₃)
lvCombine-comm : {a} (f : CombineForPLT a)
( plt PartialComm (PartialLatticeType._≈_ plt) (f plt))
(L : List (PartialLatticeType a))
PartialComm (eqL L) (lvCombine f L)
lvCombine-comm f f-comm L@(plt plts) lv₁@(inj₁ v₁) (inj₁ v₂)
rewrite lvCombine-homo₁ plt plts f ((` v₁) (` v₂)) = lift-≈-map inj₁ _ _ (λ _ _ x x) _ _ (f-comm plt v₁ v₂)
lvCombine-comm f f-comm (plt plts) (inj₂ lv₁) (inj₂ lv₂) = lift-≈-map inj₂ _ _ (λ _ _ x x) _ _ (lvCombine-comm f f-comm plts lv₁ lv₂)
lvCombine-comm f f-comm (plt plts) (inj₁ v₁) (inj₂ lv₂) = ≈-nothing
lvCombine-comm f f-comm (plt plts) (inj₂ lv₁) (inj₁ v₂) = ≈-nothing
lvCombine-idemp : {a} (f : CombineForPLT a)
( plt PartialIdemp (PartialLatticeType._≈_ plt) (f plt))
(L : List (PartialLatticeType a))
PartialIdemp (eqL L) (lvCombine f L)
lvCombine-idemp f f-idemp (plt plts) (inj₁ v) = lift-≈-map inj₁ _ _ (λ _ _ x x) _ _ (f-idemp plt v)
lvCombine-idemp f f-idemp (plt plts) (inj₂ lv) = lift-≈-map inj₂ _ _ (λ _ _ x x) _ _ (lvCombine-idemp f f-idemp plts lv)
lvJoin-assoc : {a} (L : List (PartialLatticeType a)) PartialAssoc (eqL L) (lvJoin L)
lvJoin-assoc = lvCombine-assoc PartialLatticeType._⊔?_ PartialLatticeType.⊔-assoc
lvJoin-comm : {a} (L : List (PartialLatticeType a)) PartialComm (eqL L) (lvJoin L)
lvJoin-comm = lvCombine-comm PartialLatticeType._⊔?_ PartialLatticeType.⊔-comm
lvJoin-idemp : {a} (L : List (PartialLatticeType a)) PartialIdemp (eqL L) (lvJoin L)
lvJoin-idemp = lvCombine-idemp PartialLatticeType._⊔?_ PartialLatticeType.⊔-idemp
lvMeet-assoc : {a} (L : List (PartialLatticeType a)) PartialAssoc (eqL L) (lvMeet L)
lvMeet-assoc = lvCombine-assoc PartialLatticeType._⊓?_ PartialLatticeType.⊓-assoc
lvMeet-comm : {a} (L : List (PartialLatticeType a)) PartialComm (eqL L) (lvMeet L)
lvMeet-comm = lvCombine-comm PartialLatticeType._⊓?_ PartialLatticeType.⊓-comm
lvMeet-idemp : {a} (L : List (PartialLatticeType a)) PartialIdemp (eqL L) (lvMeet L)
lvMeet-idemp = lvCombine-idemp PartialLatticeType._⊓?_ PartialLatticeType.⊓-idemp
lvJoin-greatest-total : {a} {L : Layer a} (lv₁ lv₂ : LayerValue L) LayerGreatest L lvJoin (toList L) lv₁ lv₂ nothing
lvJoin-greatest-total {L = plt ∷⁺ []} (inj₁ v₁) (inj₁ v₂) (MkLayerGreatest {{hasGreatest = hasGreatest}}) v₁⊔v₂≡nothing
with IsPartialLattice.HasGreatestElement.not-partial (PartialLatticeType.isPartialLattice plt) hasGreatest v₁ v₂
... | (v₁v₂ , v₁⊔v₂≡justv₁v₂)
with trans (cong (Maybe.map inj₁) (sym v₁⊔v₂≡justv₁v₂)) v₁⊔v₂≡nothing
... | ()
pathJoin'-greatest-total : {a} {Ls : Layers a} (p₁ p₂ : Path' Ls) LayerGreatest (head Ls) pathJoin' Ls p₁ p₂ nothing
pathJoin'-greatest-total {Ls = single L} lv₁ lv₂ layerGreatest lv₁⊔lv₂≡nothing = lvJoin-greatest-total {L = L} lv₁ lv₂ layerGreatest lv₁⊔lv₂≡nothing
pathJoin'-greatest-total {Ls = add-via-greatest L _} (inj₁ lv₁) (inj₁ lv₂) layerGreatest _
with nothing <- lvJoin (toList L) lv₁ lv₂ in lv₁⊔?lv₂=? = lvJoin-greatest-total {L = L} lv₁ lv₂ layerGreatest lv₁⊔?lv₂=?
pathJoin'-greatest-total {Ls = add-via-least L _} (inj₁ lv₁) (inj₁ lv₂) layerGreatest _
with nothing <- lvJoin (toList L) lv₁ lv₂ in lv₁⊔?lv₂=? = lvJoin-greatest-total {L = L} lv₁ lv₂ layerGreatest lv₁⊔?lv₂=?
pathJoin'-greatest-total {Ls = add-via-least (plt ∷⁺ []) {{MkLayerLeast {{hasLeast = hasLeast}}}} Ls'} (inj₂ p₁) (inj₂ p₂) (MkLayerGreatest {{hasGreatest = hasGreatest}}) inj₂p₁⊔inj₂p₂≡nothing
with pathJoin' Ls' p₁ p₂ | inj₂p₁⊔inj₂p₂≡nothing
... | nothing | ()
... | just _ | ()
pathJoin'-greatest-total {Ls = add-via-greatest L Ls {{layerGreatest}}} (inj₂ p₁) (inj₂ p₂) _ inj₂p₁⊔inj₂p₂≡nothing
with pathJoin' Ls p₁ p₂ in p₁⊔p₂=? | inj₂p₁⊔inj₂p₂≡nothing
... | just p₁⊔p₂ | ()
... | nothing | refl = pathJoin'-greatest-total {Ls = Ls} p₁ p₂ layerGreatest p₁⊔p₂=?
pathJoin'-comm : {a} {Ls : Layers a} PartialComm (eqPath' Ls) (pathJoin' Ls)
pathJoin'-comm {Ls = single l} lv₁ lv₂ = lvJoin-comm (toList l) lv₁ lv₂
pathJoin'-comm {Ls = add-via-least l ls} (inj₁ lv₁) (inj₁ lv₂) = lift-≈-map inj₁ _ _ (λ _ _ x x) _ _ (lvJoin-comm (toList l) lv₁ lv₂)
pathJoin'-comm {Ls = add-via-least l@(plt ∷⁺ []) {{MkLayerLeast {{hasLeast = hasLeast}}}} ls} (inj₂ p₁) (inj₂ p₂)
with pathJoin' ls p₁ p₂ | pathJoin' ls p₂ p₁ | pathJoin'-comm {Ls = ls} p₁ p₂
... | just p | just p' | ≈-just p≈p' = ≈-just p≈p'
... | nothing | nothing | ≈-nothing = ≈-just (eqLv-refl l (inj₁ (IsPartialSemilattice.HasAbsorbingElement.x hasLeast)))
pathJoin'-comm {Ls = add-via-least l ls} (inj₁ lv₁) (inj₂ p₂) = ≈-just (eqLv-refl l lv₁)
pathJoin'-comm {Ls = add-via-least l ls} (inj₂ p₁) (inj₁ lv₂) = ≈-just (eqLv-refl l lv₂)
pathJoin'-comm {Ls = add-via-greatest l ls} (inj₁ lv₁) (inj₁ lv₂) = lift-≈-map inj₁ _ _ (λ _ _ x x) _ _ (lvJoin-comm (toList l) lv₁ lv₂)
pathJoin'-comm {Ls = add-via-greatest l ls} (inj₂ p₁) (inj₂ p₂) = lift-≈-map inj₂ _ _ (λ _ _ x x) _ _ (pathJoin'-comm {Ls = ls} p₁ p₂)
pathJoin'-comm {Ls = add-via-greatest l ls} (inj₁ lv₁) (inj₂ p₂) = ≈-just (eqLv-refl l lv₁)
pathJoin'-comm {Ls = add-via-greatest l ls} (inj₂ p₁) (inj₁ lv₂) = ≈-just (eqLv-refl l lv₂)
pathMeet'-comm : {a} {Ls : Layers a} PartialComm (eqPath' Ls) (pathMeet' Ls)
pathMeet'-comm {Ls = single l} lv₁ lv₂ = lvMeet-comm (toList l) lv₁ lv₂
pathMeet'-comm {Ls = add-via-least l ls} (inj₁ lv₁) (inj₁ lv₂) = lift-≈-map inj₁ _ _ (λ _ _ x x) _ _ (lvMeet-comm (toList l) lv₁ lv₂)
pathMeet'-comm {Ls = add-via-least l ls} (inj₂ p₁) (inj₂ p₂) = lift-≈-map inj₂ _ _ (λ _ _ x x) _ _ (pathMeet'-comm {Ls = ls} p₁ p₂)
pathMeet'-comm {Ls = add-via-least l ls} (inj₁ lv₁) (inj₂ p₂) = ≈-just (eqPath'-refl ls p₂)
pathMeet'-comm {Ls = add-via-least l ls} (inj₂ p₁) (inj₁ lv₂) = ≈-just (eqPath'-refl ls p₁)
pathMeet'-comm {Ls = add-via-greatest l ls {{greatest}}} (inj₁ lv₁) (inj₁ lv₂)
with lvMeet (toList l) lv₁ lv₂ | lvMeet (toList l) lv₂ lv₁ | lvMeet-comm (toList l) lv₁ lv₂
... | just lv | just lv' | ≈-just lv≈lv' = ≈-just lv≈lv'
... | nothing | nothing | ≈-nothing
with ls | greatest | valueAtHead ls
-- begin dumb: don't know why, but abstracting on `head ls` leads to an ill-formed case
... | single l' | MkLayerGreatest {{hasGreatest = hasGreatest}} | vah
= ≈-just (eqLv-refl l' (vah (inj₁ (IsPartialSemilattice.HasAbsorbingElement.x hasGreatest))))
... | add-via-least l' {{least = least}} ls' | MkLayerGreatest {{hasGreatest = hasGreatest}} | vah
= ≈-just (eqPath'-refl (add-via-least l' {{least}} ls') (vah (inj₁ (IsPartialSemilattice.HasAbsorbingElement.x hasGreatest))))
... | add-via-greatest l' ls' {{greatest = greatest'}} | MkLayerGreatest {{hasGreatest = hasGreatest}} | vah
= ≈-just (eqPath'-refl (add-via-greatest l' ls' {{greatest'}}) (vah (inj₁ (IsPartialSemilattice.HasAbsorbingElement.x hasGreatest))))
-- end dumb
pathMeet'-comm {Ls = add-via-greatest l ls {{greatest}}} (inj₂ p₁) (inj₂ p₂) = lift-≈-map inj₂ _ _ (λ _ _ x x) _ _ (pathMeet'-comm {Ls = ls} p₁ p₂)
pathMeet'-comm {Ls = add-via-greatest l ls} (inj₁ lv₁) (inj₂ p₂) = ≈-just (eqPath'-refl ls p₂)
pathMeet'-comm {Ls = add-via-greatest l ls} (inj₂ p₁) (inj₁ lv₂) = ≈-just (eqPath'-refl ls p₁)
record _≈_ {a} {Ls : Layers a} (p₁ p₂ : Path Ls) : Set a where
field pathEq : eqPath' Ls (Path.path p₁) (Path.path p₂)
_⊔̇_ : {a} {Ls : Layers a} (p₁ p₂ : Path Ls) Maybe (Path Ls)
_⊔̇_ {a} {ls} p₁ p₂ = Maybe.map MkPath (pathJoin' ls (Path.path p₁) (Path.path p₂))
_⊓̇_ : {a} {Ls : Layers a} (p₁ p₂ : Path Ls) Maybe (Path Ls)
_⊓̇_ {a} {ls} p₁ p₂ = Maybe.map MkPath (pathMeet' ls (Path.path p₁) (Path.path p₂))
-- data ListValue {a : Level} : List (PartialLatticeType a) → Set (lsuc a) where
-- here : ∀ {plt : PartialLatticeType a} {pltl : List (PartialLatticeType a)}
-- (v : PartialLatticeType.EltType plt) → ListValue (plt ∷ pltl)
-- there : ∀ {plt : PartialLatticeType a} {pltl : List (PartialLatticeType a)} →
-- ListValue pltl → ListValue (plt ∷ pltl)