Add some cases for associativity lemma

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2026-02-16 15:08:57 -08:00
parent 3f923c2d7d
commit 9072da4ab6

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@@ -608,7 +608,9 @@ record Graph : Set where
}
module Tagged (noCycles : NoCycles) (total-⊔ : Total-⊔) (total-⊓ : Total-⊓) (𝓛 : Node Σ Set FiniteHeightLattice) where
open Basic noCycles total-⊔ total-⊓ using () renaming (_⊔_ to _⊔ᵇ_; _⊓_ to _⊓ᵇ_; ⊔-idemp to ⊔ᵇ-idemp; ⊔-comm to ⊔ᵇ-comm; ⊔-assoc to ⊔ᵇ-assoc; _≼_ to _≼ᵇ_)
open Basic noCycles total-⊔ total-⊓ using () renaming (_⊔_ to _⊔ᵇ_; _⊓_ to _⊓ᵇ_; ⊔-idemp to ⊔ᵇ-idemp; ⊔-comm to ⊔ᵇ-comm; ⊔-assoc to ⊔ᵇ-assoc; _≼_ to _≼ᵇ_; isJoinSemilattice to isJoinSemilatticeᵇ; isMeetSemilattice to isMeetSemilatticeᵇ; isLattice to isLatticeᵇ)
open IsLattice isLatticeᵇ using () renaming (≈-⊔-cong to ≡-⊔ᵇ-cong)
Elem : Set
Elem = Σ Node λ n (proj₁ (𝓛 n))
@@ -657,60 +659,85 @@ record Graph : Set where
... | no _ | no _ = ≈-lift (FiniteHeightLattice.≈-refl (proj₂ (𝓛 n)))
private
data Expr (A : Set) : Set where
`_ : A Expr A
_⊔ᵉ_ : Expr A Expr A Expr A
scary : (n₁ n₂ : Node) (p : n₁ n₂) (n₁ n₂) subst (λ n Dec (n₁ n)) p (yes refl)
scary n₁ n₂ refl with n₁ n₂
... | yes refl = refl
... | no n₁≢n₂ = ⊥-elim (n₁≢n₂ refl)
eval : {A} (A A A) Expr A A
eval _ (` v) = v
eval f (e ⊔ᵉ e₂) = f (eval f e₁) (eval f e₂)
payloadˡ : e₁ e₂ e₃ let n = proj₁ ((e₁ e₂) e₃)
in proj₁ (𝓛 n)
payloadˡ (n , l₁) (n₂ , l₂) (n₃ , l₃)
with n (n₁ ⊔ᵇ n₂) ⊔ᵇ n₃
using _⊔ⁿ_ FiniteHeightLattice._⊔_ (proj₂ (𝓛 n))
with n n₁ | n n₂ | n n₃
... | yes refl | yes refl | yes refl = (l₁ ⊔ⁿ l₂) ⊔ⁿ l₃
... | yes refl | yes refl | no _ = l₁ ⊔ⁿ l₂
... | yes refl | no _ | yes refl = l₁ ⊔ⁿ l₃
... | yes refl | no _ | no _ = l₁
... | no _ | yes refl | yes refl = l₂ ⊔ⁿ l₃
... | no _ | yes refl | no _ = l₂
... | no _ | no _ | yes refl = l₃
... | no _ | no _ | no _ = FiniteHeightLattice.⊥ (proj₂ (𝓛 n))
mapᵉ : {A B} (A B) Expr A Expr B
mapᵉ f (` a) = ` (f a)
mapᵉ f (e ⊔ᵉ e₂) = (mapᵉ f e₁) ⊔ᵉ (mapᵉ f e₂)
payloadʳ : e₁ e₂ e₃ let n = proj₁ (e₁ (e₂ e₃))
in proj₁ (𝓛 n)
payloadʳ (n , l₁) (n₂ , l₂) (n₃ , l₃)
with n n₁ ⊔ᵇ (n₂ ⊔ᵇ n₃)
using _⊔ⁿ_ FiniteHeightLattice._⊔_ (proj₂ (𝓛 n))
with n n₁ | n n₂ | n n₃
... | yes refl | yes refl | yes refl = l₁ ⊔ⁿ (l₂ ⊔ⁿ l₃)
... | yes refl | yes refl | no _ = l₁ ⊔ⁿ l₂
... | yes refl | no _ | yes refl = l₁ ⊔ⁿ l₃
... | yes refl | no _ | no _ = l₁
... | no _ | yes refl | yes refl = l₂ ⊔ⁿ l₃
... | no _ | yes refl | no _ = l₂
... | no _ | no _ | yes refl = l₃
... | no _ | no _ | no _ = FiniteHeightLattice.⊥ (proj₂ (𝓛 n))
filterᵉ : (n : Node) Expr Elem Maybe (Expr (proj₁ (𝓛 n)))
filterᵉ n (` (n' , l'))
with n n'
... | yes refl = just (` l')
... | no _ = nothing
filterᵉ n (e₁ ⊔ᵉ e)
with filterᵉ n e₁ | filterᵉ n e₂
... | just e₁' | just e₂' = just (e₁' ⊔ᵉ e₂')
... | just e₁' | nothing = just e₁'
... | nothing | just e₂' = just e₂'
... | nothing | nothing = nothing
Reassocˡ : e₁ e₂ e₃
((e₁ e₂) e₃) (proj₁ ((e₁ e₂) e₃) , payloadˡ e₁ e₂ e₃)
Reassocˡ (n₁ , l₁) (n₂ , l₂) (n₃ , l₃)
with n (n₁ ⊔ᵇ n₂) ⊔ᵇ n₃ in pⁿ
with n n₁ | n n₂ | n n₃
Reassocˡ (n₁ , l₁) (n₂ , l) (n₃ , l₃)
| yes refl | yes refl | yes refl
with (n₁ ⊔ᵇ n₁) n₁
... | no n₁≢n₁ = ⊥-elim (n₁≢n₁ (⊔ᵇ-idemp n₁))
... | yes p rewrite p
with n₁ n₁
... | no n₁≢n₁ = ⊥-elim (n₁≢n₁ refl)
... | yes refl = ≈-refl
Reassocˡ (n₁ , l₁) (n₂ , l₂) (n₃ , l₃)
| yes refl | yes refl | no _
with (n₁ ⊔ᵇ n₁) n₁
... | no n₁≢n₁ = ⊥-elim (n₁≢n₁ (⊔ᵇ-idemp n₁))
... | yes p rewrite p
with n₁ n₁
... | no n₁≢n₁ = ⊥-elim (n₁≢n₁ refl)
... | yes refl = ≈-refl
Reassocˡ (n₁ , l₁) (n₂ , l₂) (n₃ , l₃)
| yes p₁@refl | no n₁≢n₂ | yes p₃@refl
using n₁⊔n₂≡n₁ trans (trans (trans (≡-⊔ᵇ-cong (sym (⊔ᵇ-idemp n₁)) (refl {x = n₂})) (⊔ᵇ-assoc n₁ n₁ n₂)) (⊔ᵇ-comm n₁ (n₁ ⊔ᵇ n₂))) pⁿ
with (n₁ ⊔ᵇ n₂) n₁
... | no n₁⊔n₂≢n₁ = ⊥-elim (n₁⊔n₂≢n₁ n₁⊔n₂≡n₁)
... | yes p rewrite p
with n₁ n₁ | n₁ n₂
... | no n₁≢n₁ | _ = ⊥-elim (n₁≢n₁ refl)
... | _ | yes n₁≡n₂ = ⊥-elim (n₁≢n₂ n₁≡n₂)
... | yes refl | no _ = ≈-refl
Reassocˡ (n₁ , l₁) (n₂ , l₂) (n₃ , l₃)
| yes p₁@refl | no n₁≢n₂ | no n₁≢n₃ = {!!}
Node-homo : e proj₁ (eval _⊔_ e) eval _⊔ᵇ_ (mapᵉ proj₁ e)
Node-homo (` _) = refl
Node-homo (e₁ ⊔ᵉ e)
with IH₁ Node-homo e₁ with IH₂ Node-homo e₂
with (n₁ , l₁) eval _⊔_ e₁ with (n₂ , l₂) eval _⊔_ e₂
with n n₁ ⊔ᵇ n₂ in p
with n n₁ | n n₂
... | yes refl | yes refl rewrite sym IH₁ rewrite sym IH₂ = sym (⊔ᵇ-idemp n)
... | yes refl | no _ rewrite sym IH₁ rewrite sym IH₂ = sym p
... | no _ | yes refl rewrite sym IH₁ rewrite sym IH₂ = sym p
... | no _ | no _ rewrite sym IH₁ rewrite sym IH₂ = sym p
-- A key simplifying property is that notionally, only the
-- "elements with the final tag" in the expression matter. All
-- others are subsumed. If none of the elments have the final tag,
-- we've found a better supremum and the second element will be ⊥.
Expr-final : e let n = proj₁ (eval _⊔_ e)
⊥ⁿ = FiniteHeightLattice.⊥ (proj₂ (𝓛 n))
_⊔ⁿ_ = FiniteHeightLattice._⊔_ (proj₂ (𝓛 n))
in (eval _⊔_ e) (n , Maybe.maybe (eval _⊔ⁿ_) ⊥ⁿ (filterᵉ n e))
Expr-final = {!!}
Reassocʳ : e e₂ e₃
(e₁ (e₂ e₃)) (proj₁ (e₁ (e₂ e₃)) , payloadʳ e₁ e₂ e₃)
Reassocʳ (n₁ , l₁) (n₂ , l) (n₃ , l₃) = {!!}
⊔-assoc : (e₁ e₂ e₃ : Elem) ((e₁ e₂) e₃) (e₁ (e₂ e₃))
⊔-assoc e₁@(n₁ , l₁) e₂@(n₂ , l₂) e₃@(n₃ , l₃)
using exprˡ (((` e₁) ⊔ᵉ (` e₂)) (` e₃))
using exprʳ ((` e₁) ((` e₂) ⊔ᵉ (` e₃)))
with proj₁ (eval _⊔_ exprˡ) in
with proj₁ (eval _⊔_ exprʳ) in
with final₁ Expr-final exprˡ
with final₂ Expr-final exprʳ
with proj₁ ((e₁ e₂) e₃) in
with proj₁ (e₁ (e₂ e₃)) in
with final₁ Reassocˡ e₁ e₂ e₃
with final₂ Reassocʳ e₁ e₂ e₃
rewrite rewrite
rewrite ⊔ᵇ-assoc n₁ n₂ n₃
rewrite trans (sym )