module FOL.Syntax where
open import SOAS.Common
open import SOAS.Context
open import SOAS.Variable
open import SOAS.Families.Core
open import SOAS.Construction.Structure
open import SOAS.ContextMaps.Inductive
open import SOAS.Metatheory.Syntax
open import FOL.Signature
private
variable
Γ Δ Π : Ctx
α : FOLT
𝔛 : Familyₛ
module FOL:Terms (𝔛 : Familyₛ) where
data FOL : Familyₛ where
var : ℐ ⇾̣ FOL
mvar : 𝔛 α Π → Sub FOL Π Γ → FOL α Γ
⊥ : FOL * Γ
_∨_ : FOL * Γ → FOL * Γ → FOL * Γ
⊤ : FOL * Γ
_∧_ : FOL * Γ → FOL * Γ → FOL * Γ
¬_ : FOL * Γ → FOL * Γ
_≟_ : FOL N Γ → FOL N Γ → FOL * Γ
∀′ : FOL * (N ∙ Γ) → FOL * Γ
∃′ : FOL * (N ∙ Γ) → FOL * Γ
infixl 20 _∨_
infixl 20 _∧_
infixr 50 ¬_
infixl 20 _≟_
open import SOAS.Metatheory.MetaAlgebra ⅀F 𝔛
FOLᵃ : MetaAlg FOL
FOLᵃ = record
{ 𝑎𝑙𝑔 = λ where
(falseₒ ⅋ _) → ⊥
(orₒ ⅋ a , b) → _∨_ a b
(trueₒ ⅋ _) → ⊤
(andₒ ⅋ a , b) → _∧_ a b
(notₒ ⅋ a) → ¬_ a
(eqₒ ⅋ a , b) → _≟_ a b
(allₒ ⅋ a) → ∀′ a
(exₒ ⅋ a) → ∃′ a
; 𝑣𝑎𝑟 = var ; 𝑚𝑣𝑎𝑟 = λ 𝔪 mε → mvar 𝔪 (tabulate mε) }
module FOLᵃ = MetaAlg FOLᵃ
module _ {𝒜 : Familyₛ}(𝒜ᵃ : MetaAlg 𝒜) where
open MetaAlg 𝒜ᵃ
𝕤𝕖𝕞 : FOL ⇾̣ 𝒜
𝕊 : Sub FOL Π Γ → Π ~[ 𝒜 ]↝ Γ
𝕊 (t ◂ σ) new = 𝕤𝕖𝕞 t
𝕊 (t ◂ σ) (old v) = 𝕊 σ v
𝕤𝕖𝕞 (mvar 𝔪 mε) = 𝑚𝑣𝑎𝑟 𝔪 (𝕊 mε)
𝕤𝕖𝕞 (var v) = 𝑣𝑎𝑟 v
𝕤𝕖𝕞 ⊥ = 𝑎𝑙𝑔 (falseₒ ⅋ tt)
𝕤𝕖𝕞 (_∨_ a b) = 𝑎𝑙𝑔 (orₒ ⅋ 𝕤𝕖𝕞 a , 𝕤𝕖𝕞 b)
𝕤𝕖𝕞 ⊤ = 𝑎𝑙𝑔 (trueₒ ⅋ tt)
𝕤𝕖𝕞 (_∧_ a b) = 𝑎𝑙𝑔 (andₒ ⅋ 𝕤𝕖𝕞 a , 𝕤𝕖𝕞 b)
𝕤𝕖𝕞 (¬_ a) = 𝑎𝑙𝑔 (notₒ ⅋ 𝕤𝕖𝕞 a)
𝕤𝕖𝕞 (_≟_ a b) = 𝑎𝑙𝑔 (eqₒ ⅋ 𝕤𝕖𝕞 a , 𝕤𝕖𝕞 b)
𝕤𝕖𝕞 (∀′ a) = 𝑎𝑙𝑔 (allₒ ⅋ 𝕤𝕖𝕞 a)
𝕤𝕖𝕞 (∃′ a) = 𝑎𝑙𝑔 (exₒ ⅋ 𝕤𝕖𝕞 a)
𝕤𝕖𝕞ᵃ⇒ : MetaAlg⇒ FOLᵃ 𝒜ᵃ 𝕤𝕖𝕞
𝕤𝕖𝕞ᵃ⇒ = record
{ ⟨𝑎𝑙𝑔⟩ = λ{ {t = t} → ⟨𝑎𝑙𝑔⟩ t }
; ⟨𝑣𝑎𝑟⟩ = refl
; ⟨𝑚𝑣𝑎𝑟⟩ = λ{ {𝔪 = 𝔪}{mε} → cong (𝑚𝑣𝑎𝑟 𝔪) (dext (𝕊-tab mε)) } }
where
open ≡-Reasoning
⟨𝑎𝑙𝑔⟩ : (t : ⅀ FOL α Γ) → 𝕤𝕖𝕞 (FOLᵃ.𝑎𝑙𝑔 t) ≡ 𝑎𝑙𝑔 (⅀₁ 𝕤𝕖𝕞 t)
⟨𝑎𝑙𝑔⟩ (falseₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (orₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (trueₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (andₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (notₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (eqₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (allₒ ⅋ _) = refl
⟨𝑎𝑙𝑔⟩ (exₒ ⅋ _) = refl
𝕊-tab : (mε : Π ~[ FOL ]↝ Γ)(v : ℐ α Π) → 𝕊 (tabulate mε) v ≡ 𝕤𝕖𝕞 (mε v)
𝕊-tab mε new = refl
𝕊-tab mε (old v) = 𝕊-tab (mε ∘ old) v
module _ (g : FOL ⇾̣ 𝒜)(gᵃ⇒ : MetaAlg⇒ FOLᵃ 𝒜ᵃ g) where
open MetaAlg⇒ gᵃ⇒
𝕤𝕖𝕞! : (t : FOL α Γ) → 𝕤𝕖𝕞 t ≡ g t
𝕊-ix : (mε : Sub FOL Π Γ)(v : ℐ α Π) → 𝕊 mε v ≡ g (index mε v)
𝕊-ix (x ◂ mε) new = 𝕤𝕖𝕞! x
𝕊-ix (x ◂ mε) (old v) = 𝕊-ix mε v
𝕤𝕖𝕞! (mvar 𝔪 mε) rewrite cong (𝑚𝑣𝑎𝑟 𝔪) (dext (𝕊-ix mε))
= trans (sym ⟨𝑚𝑣𝑎𝑟⟩) (cong (g ∘ mvar 𝔪) (tab∘ix≈id mε))
𝕤𝕖𝕞! (var v) = sym ⟨𝑣𝑎𝑟⟩
𝕤𝕖𝕞! ⊥ = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! (_∨_ a b) rewrite 𝕤𝕖𝕞! a | 𝕤𝕖𝕞! b = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! ⊤ = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! (_∧_ a b) rewrite 𝕤𝕖𝕞! a | 𝕤𝕖𝕞! b = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! (¬_ a) rewrite 𝕤𝕖𝕞! a = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! (_≟_ a b) rewrite 𝕤𝕖𝕞! a | 𝕤𝕖𝕞! b = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! (∀′ a) rewrite 𝕤𝕖𝕞! a = sym ⟨𝑎𝑙𝑔⟩
𝕤𝕖𝕞! (∃′ a) rewrite 𝕤𝕖𝕞! a = sym ⟨𝑎𝑙𝑔⟩
FOL:Syn : Syntax
FOL:Syn = record
{ ⅀F = ⅀F
; ⅀:CS = ⅀:CompatStr
; mvarᵢ = FOL:Terms.mvar
; 𝕋:Init = λ 𝔛 → let open FOL:Terms 𝔛 in record
{ ⊥ = FOL ⋉ FOLᵃ
; ⊥-is-initial = record { ! = λ{ {𝒜 ⋉ 𝒜ᵃ} → 𝕤𝕖𝕞 𝒜ᵃ ⋉ 𝕤𝕖𝕞ᵃ⇒ 𝒜ᵃ }
; !-unique = λ{ {𝒜 ⋉ 𝒜ᵃ} (f ⋉ fᵃ⇒) {x = t} → 𝕤𝕖𝕞! 𝒜ᵃ f fᵃ⇒ t } } } }
open Syntax FOL:Syn public
open FOL:Terms public
open import SOAS.Families.Build public
open import SOAS.Syntax.Shorthands FOLᵃ public
open import SOAS.Metatheory FOL:Syn public
_⟹_ : FOL 𝔛 * Γ → FOL 𝔛 * Γ → FOL 𝔛 * Γ
p ⟹ q = ¬ p ∨ q